DEVELOPMENT DF A SINBLE-SLCIPE · 2018. 10. 23. · DEVELOPMENT OF A SINGLE-SLOPE CONCRETE MEDIAN BARRIER by W. Lynn Beason, H.E. Ross, Jr., H.S. Perera, Wanda Campise, and D.L. Bullard,Jr

[EXAS IRANSPORTATION [NSTITUTE

DEVELOPMENT DF A SINBLE-SLCIPE

CONCRETE ME·DIAN BARRIER

ey·

W. Lynn Beason, H.E. Ross, Jr.,

H.S. Perera, Wanda L. Campise and D.L. Bullard, Jr.

REPORT ND. ·&42SCDK-1

TEXAS TRANSPORTATION INSTITUTE

THE TEXAS A&M UNIVERSITY SYSTEM

COLLEGE STATION, TEXAS

STATE DIEPARTMENT OF HIGHWAYS

AND PUBLIC TRANSPORTATION

DEVELOPMENT OF A SINGLE-SLOPE CONCRETE MEDIAN BARRIER

by

W. Lynn Beason, H.E. Ross, Jr., H.S. Perera, Wanda Campise, and D.L. Bullard,Jr.

Research Report No. 9429CDK-1

Sponsored by State Department of Highways and Public Transportation

June 1989

Texas Transportation Institute The Texas A&M University System College Station, Texas 77843

-· -·

METRIC (SI*) CONVERSIO-N FACTORS APPROXIMATE C.ONVERSIONS TO SI UNITS

Symbol When Yau KIMM Multlply· ly To Find

In ft yd ml

tn• ftl

yd' ml• ac

oz lb T

LENGTH

mllllmetres metres m•trea

Inches feet yards mlles

2.54 0.3048 0.914 1.81 • ktlometrea

square lnchea square feet square yards square mlles acres

AREA

145.2 0.0929 0.838 U9 0.395

mUlhnetres squared metres squared metres squared kilometres squared hectares

MASS· (weight)

ounces 28.35 pounds 0.454 short tons (2000 lb) 0~907

VOLUME

grams kilograms megagrams

fl oz fluld ounces 29.57 mUUUtres gal gallons 3.785 litres ft• cubic feet 0.0328 metres cubed yd1 cubic yards 0.0765 metres cubed

NOTE: Volumes greater than 1000L shall be shown In m•.

TEMPERATURE (exact)

°F Fahrenheit 5/9 (after Celslua temperature . subtracting 32) temperature

• SI Is the symbol for the lnternaUonal System of Measurements

mm m m km

mm• m• m• km1

ha

g kg Mg

ml L m• m•

..

•

..

..

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•

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---= -------~ -----

----

=---=

= =

=-

=

.. ...

.. .. .. ..

=

.. •

..

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= .• = u

APPROXl·MATE CONVERSIONS TO SI UNITS Symbol WhM You Know

mm m m km

mUHmetres metres metres kilometres

Multlply By

LENGTH

0.039 3.28 1.09 0.621

AREA mm• millimetres squared 0.0018 m2 metres squared 10. 76' km' kilometres squared 0.39 ha hectares (10 000 ml) · 2.53

To Find

Inches feet yards miles

square Inches square feet square miles acres

MASS (weight)

0 kg

grams o.0353 kilograms 2.205

Mg megagrams (1000 kg) 1.103

ml mUllUtres L litres m1 metres cubed m• metres cubed

VOLUME

0.034 0.264 35.315 1.308

ounces pounds short tons

fluid ounces gallons cubic feet cubic yards

TEMPERATURE (exact)

oC Celsius 9/5 (then temperature add 32)

Fahrenheit temperature

OF Of 32 98.8 212

-f I I I ? I I 114:0 I I I ~ e l I 1~ I ' I 1~ e I t ~•I. i i I I i· .1 I I· I i .. " -.co -20 o 20 40 . eo ao 100 ~ ~ . ~

These factors conform to the requirement of FHWA Order 5190.1A.

tn ft yd ml

ln1

ft• mi• ac

oz lb T

fl oz gal ft1

yd*

DISCLAIMER

The contents of this report reflect the views of the authors, who are responsible for the opinions, findings, and conclusions presented herein. The contents do not necessarily reflect the official view or polici,es of the Texas State Department of Highways and Public Transportation (SOHPT}. This report does not constitute a standard, specification, or regulation.

KEY WORDS

Concrete Median Barrier, Crash Test(s}, Construction, Safety

ACKNOWLEDGMENTS

This research study was conducted under the sponsorship of the SDHPT. Messrs. Mark Marek, Harold Cooner, and Gary Humes of the SOHPT worked closely with the researchers. Their comments, suggestions, and cooperative spirit were appreciated.

iii

DEVELOPMENT OFA SINGLE-SLOPE CONCRETE MEDIAN BARRIER

ABSTRACT

A single-slope concrete median barrier (CMB) has been developed for use as either a permanent concrete median barrier or as a temporary construction zone barrier. The new barrier is designed to meet accepted criteria for the performance of longitudinal barriers. The new single-slope CMB is designed to be used in applications where the New Jersey CMB would be employed. The primary advantage of the new single-slope CMB is that the pavement adjacent to the new barrier can be overlaid several times without changing the performance of the barrier. This should help to reduce the maintenance costs associated with the use of permanent CMB' s. Results of four crash tests are presented which show that the performance of the new single-slope CMB is roughly equivalent to the performance of the New Jersey CMB. These tests were conducted with the new single-slope CMB deployed in both the permanent and temporary configurations.

iv

TABLE OF CONTENTS

INTRODUCTION •••••....••••.•... ~ . . . . • . . . • . • . . . • . • • . . . . . . . . . . • . . • • .. . . . • . . . 1

DEVELOPMENT OF THE SINGLE-SLOPE CMB .....••..........•••..•..•..•.••.... 3 F·ULL-SCALE CRA .. SH TES.T·S •.............................................. , . . • . 13

RESULTS FROM TEST 9429C-l.. . • • • . • • . . • . . . . . . • • • . . . . • . . . . . .. • . . • . . • • • 14 RESULTS FROM TEST 9429C-2 ••.•••.••..•.....•••••........ 94! ••••••••• 28 RE SUL TS FROM TEST 94 29C-3 • . . . . . . . . . • . . • . . . . . . . . . . . . • • • . . . • • . . . . • . . 3 7 RESULTS FROM TEST 9429K-l .••..•.•................ ~················ 47

CONC LUS I O·NS • ••••.•••••••••••••••••.•••••••••••• ·• • • • • • .• • • • • • • • . • • • • • • • • • • • 5 7

APPENDIX A. FABRICATION DETAILS FOR SINGLE-SLOPE CMB ......•......••... 59 APPENDIX B. SEQUENTIAL PHOTOGRAPHS OF CRASH TESTS .............•.•..... 62 APPENDIX C. ACCELEROMETER TRACES AND PLOTS OF

ROLL, PITCH, AND YAW RA TES. . . . . . . . . . . . . • . . . . • . . • . . . . . . . . • . 71 .REFER.E.N·CES •• •••••••••••••••• ~ • .• • • • • • • .• • • • • • • • • • • • • • • • • • • . • • • • • .• • • • • • • • • 88

v

Figure No. 1

2

3

4

5

6

LIST OF FIGURES

Page Idealized single-slope CMB ...•..•....•..............••.. 4 Idealized vehicle impact with single-slope CMB •......... 5 Typical cross-section of single-slope CMB ..............• 7 Comparison of single-slope and new jersey CMB's ......... 8 Temporary angle-splice connection ............•.•........ 11 Typical cross-section of permanently installed single-slope CMB ............... ~ ........................ 12

7 Permanent single-slope CMB installation ................. 15 8 Vehicle before test 9429C~l ............................. 17 9 Vehicle/barrier geometrics for test 9429C-1 ............. 18

10 Barrier before test 9429C-l ........•.•.................. 20 11 Test vehicle properties for test 9429C-l ................ 21 12 Barrier after test 9429C-l ...........................•.. 22 13 Barrier movement after test 9429C-1 ..................... 23 14 Vehicle after test 9429C-1 ...•.•.....•.................. 24 15 Damage to left rear of vehicle for test 9429C-l ..•...... 25 16 Summary of results for test 9429C-l. . . . . . . . . . . . . . . . . . . . . 27 17 Vehicle before test 9429C-2 .••...•.•.•.................. 29 18 Test installation before test 9429C~2 (impact side) .. 4 •• 30 19 Test installation before test 9429C-2 (rear side) ....... 31

. .

20 Test vehicle properties for test 9429C-2 ................ 32 21 Barrier after test 9429C-2 •...•......................... 33 22 Vehicle after test 9429C-2 .•.......•.......• 4 ••••••••••• 35 23 Summary of results for test 9429C-2 ...•.......•......... 36 24 Vehicle before test 9429C-3 ............................. 38 25 Barrier before test 9429C-3 ............................. 39 26 Test vehicle properties for test 9429C-3 ................ 40 27 Barrier after test 9429C-3 ....•......................... 42 28 Vehicle after test 9429C-3 .............................. 43 29 Damage to tires on left side for test 9429C-3 ........... 44

vi

Figure No. 30 31 32 33 34 35 36 37 38 39

40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

LIST OF FIGURES (CONTINUED)

Page Sununary of results for test 9429C-3 ......•......•....... 46 Vehicle/barrier geometrics for test 9429k-l. .......•.... 48 Vehicle before test 9429K-l .•.••.....•.................. 49 Barrier before test 9429k-l. •••••....................... 50 Test vehicle properties for test 9429K-1 ................ 51 Barrier after test 9429K-l •••••••.•.............•....... 53 Vehicle after test 9429K-l. .•..•.••....................• 54 Sununary of results for test 9429k-1 ......•.............. 56 Fabrication details for single-slope CMB ........••.•...• 60 Alternate wire mesh reinforcing scheme for single slope CM.B •• ................................................ 61

Sequential photographs for test 9429C-1 ........••.•.•... 63 Sequential photographs for test 9429C-2 ............•.... 65 Sequential photographs for test 9429C-3 ................. 67 Sequenti a 1 photographs for test 9429K- l. . . . . . . . . . . . . . . . . 69 Vehicle angular displacements for test 9429C-1 .......... 72 Longitudinal accelerometer trace for test 9429C-l ....... 73 Lateral accelerometer trace for test 9429C-l ..•.•..••... 74 Vertical accelerometer trace for test 9429C-l ...•..••... 75 Vehicle angular displacements for test 9429C-2 ......•... 76

. . . Longitudinal accelerometer trace for test 9429C-2 ....... 77 Lateral accelerometer trace for test 9429C-2 .......••..• 78 Vertical accelerometer trace for test 9429C-2 ........... 79 Vehicle angular displacements for test 9429C-3 .......... 80 Longitudinal accelerometer trace for test 9429C-3 ..•.•.• 81 Lateral accelerometer trace for test 9429C-3 ..•••..•..•• 82 Vertical accelerometer trace for test 9429C-3 ...•.....•. 83 Vehicle angular displacements for test 9429K-l .......•.. 84 Longitudinal accelerometer trace for test 9429K-1 .....•. 85

vii

Figure N(). 58

59

LIST OF FIGURES (CONTINUED)

Page Lateral accelero~eter trace for test 9429K-l ..•.•..••... 86 Vertical accelerometer trace for test 9429K-l. .....•.... 87

viii

LIST OF TABLES

Table No.

I Summary of crash test results .•••......•..•..•.••...•.•. 16

ix

INTRODUCTION

Over the past several years, New Jersey concrete median barriers (CMB)

have gained widespread acceptance. Further, other types of longitudinal

barriers employing the New Jersey shape, including bridge rails and

portable barriers, have become very popular. Full seal e crash tests have

shown that New Jersey longitudinal barriers are capable of smoothly

redirecting the standard vehicle tests specified in NCHRP 230 (1) including

both the strength and stability requirements.

While, the use of the New Jersey CMB has been successful, there are

disadvantages with its use. One of the biggest disadvantages is that the

profile of the New Jersey shape varies with height above grade. This means

that if the roadway is resurfaced, both the height of the barrier and the

shape of the barrier wil 1 be substant i a 1 ly changed. It may be that the

performance of the New Jersey safety shape is not negatively affected by

the addition of a few inches of pavement overlay. However, as the

thickness of the overlay is increased, the performance of the New Jersey

CMS will eventually become unsatisfactory if only because of the reduction

of the overall height of the barrier. Therefore, it has become fairly

standard practice to reset the New Jersey longitudinal barriers as the

pavement height is increased in the overlaying process. This process is

both expensiv~ ~nd time consuming.

The purpose of the research presented in this report was to develop a

new CMB shape whose performance is not impaired by the appl icatfon of

several inches of pavement overlays. Further, a major effort was made to

deve 1 op the geometry of the new CMB so that its effect on imp acting

vehicles is as good as or better than the effect of the New Jersey CMB.

The new barrier has a single slope face. This shape was suggested by

engineers with the Texas State Department of Highways and Public

Transportation (SDHPT). Because the barrier face has a single, constant

1

slope, its performance is not affected by overlaying the adjacent pavement.

Rather, the addi ti ona 1 pavement overlay serves to anchor the barrier more

securely at its base thus increasing its basic strength. The performance

of the single-slope CMB is ultimately controlled by its height and the slope -0f the barrier face.

The new single-slope CMB can be used in either a temporary or a permanent application. The performance of the new CMB was documented in a series of four crash tests. The first test was conducted to verify that the performance of the barrier is acceptable in a temporary application.

The second two tests were accomplished to establish the performance of the barrier in a permanent application as prescribed in NCHRP 230 {1). The

fourth test was conducted to establish the performance of the single-slope

barrier in an alternate temporary configuration.

The remainder of this report is divided into three major sections.

The next section presents a description of the newly developed single-slope

CMB. This is followed by a section on the full scale testing of the single-slope CMB. The final section presents conclusions and recommendations for the use of the single-slope CMB.

2

DEVELOPMENT OF THE SINGLE-SLOPE CMB

The objective of the research presented in this report was to develop a single-slope CMB which can be used interchangeably with the New Jersey

CMB. The design of the single-slope CMB is based on the results of a

series of computer simulations and engineering judgment as discussed below.

The basic constraints issued by engineers with the SDHPT were that the

single-slope CMB should be 42 in (106.7 cm) tall with a flat top that is a

minimum of 8 in (20.3 cm) wide. ln addition, it was required that the

impact face of the single-sl-0pe CMB incorporate a constant slope as shown

in Figure I.

It is known that a rigid barrier with a vert i ca 1 face results in the

minimum vehicle instability during impact. Vertical face rigid barriers

have undergone extensive testing with a variety of different vehicles

ranging from compact automobiles to tractor-trailers (2,3). Computer

simulations and practical experience suggest that if the face of the

barrier is sloped as shown in Figure 1, errant vehicles will be subjected

to increasing instabilities as the angle of the barrier face is increased.

If the angle of the barrier face becomes large enough, the vehicle

instabilities will lead to vehiele roll-over.

While vehicles are clearly more· stable during impacts ·with vertical

rigid barriers, there exists the possibility that the occupants in a

vehicle impacting a vertical barrier will be subjected to accelerations

that cause their heads to be propelled through the side windows of the

occupant compartment and against the vertical barrier surface. Such

movements of the occupants heads have been observed in crash tests which

incorporated anthropomorphic dummies. Therefore, it was decided to set the

angle of the barrier face so that the vehicle rolls away from the barrier

(Ref. fig. 2) to prevent this phenomenon.

- 3

e· 1 .. min. •I

Figure 1. Idealized single-slope CMB

4

Figure 2. Idealized vehicle impact with single-slope CMB

5

Computer simulations were used to study the effect of the barrier

slope on the vehicle roll. The computer program used to evaluate the

performance of the single-slope CMB was HVOSM {Highway-Vehicle-Object-

Simulation-Model) {4). The version of HVOSM used in the study was the RD2

version which incorporates modifications developed by researchers at the

Texas Transportation Institute {TTI). The TTI modifications permit the

structure of the vehicle to interact with the sloped faces of a multi-faced

rigid barrier. Studies of rigid New Jersey CMB's made with this modified

version -0f HVOSM have met with reasonably good success {5,6). Therefore,

the RD2 version of HVOSM was used to study the effects of various angles on

the performance of the single-slope CMB.

The performance of rigid longitudinal barriers is evaluated by the

stability of the vehicle after impact and the degree of deceleration due to

the impact. Angular response of the vehicle is the measure of stability

and occupant impact velocity is controlled to limit the deceleration.

Large barrier face angles {measured from vertical as shown in Figure 1)

increase the propensity for the vehicle to roll-over, while small angles

lead to high occupant impact velocities. The objective of the computer

simulation study was to select a moderate slope which will provide a good

compromise between ro 11-over tendency and occupant imp act velocities. The

HVOSM program was used to simulate the impact of a 4,500-lb {2,043 kg)

automobile traveling at 60 mph {96 km/h) with an angle of 25 degrees to

evaluate the performance of· different slopes. In addition, HVOSM was used

to examine the performance of 1,800-lb (817 kg) automobiles impacting the single-slope CMB.

Based on the above analyses and engineering judgment, it was

determined to construct the single-slope CMB so that it has a base width of

24 in (61 cm), a top width of 8 in (20.3 cm), and a height of 42 in (106.7

cm) as shown in Figure 3. Figure 4 compares the cross-section geometries

of the single-slope CMB and the New Jersey CMB. As can be seen in Figure

4, the single-slope CMB shape is approximately 30 percent taller than the

6

,.. a· ,.I

10.8°

Figure 3. Typical cross~section of single-slope CMB

7

I

1-c

112· -..)]-+-- 7"

I

r----, I \ I I I I I I I

I /

\ \ \ \

Single Slope CMB

New Jersey CMB

\ \ \

\ \

\

a· •Ill( a· •Ill( a· ~1 2·

•Ill( •Ill( a· 2· J+I( ,.,~ 7·~~112·

Figure 4. Comparison of single-slope and New Jersey CMB's

8

New Jersey CMB. The weight of the single-slope CMB is estimated to be 675

lb/ft (1000 kg/m). This estimated weight is approximately 40 percent more

than the New Jersey CMB. This weight increase is primarily due to the

increased height of the barrier. The resistance to overturning provided by

the dead weight of the single-slope CMB is approximately 20 percent more

than for the New Jersey CMB. Finally, the center-of-gravity of the single-

sl ope CMB is approximately 18 in ( 45. 7 cm) above the base compared with

approximately 11.5 in (29.2 cm) for the New Jersey CMB. The added height of the center-of-gravity results in a CMB center-of-gravity which is closer

to the center-of-gravity heights of typical automobiles. All of these

geometric factors combine to suggest that the single-slope CMB will display

a better impact response than the New Jersey CMS, particularly in the

temporary configuration.

The outputs from the computer simulations were used to determine the

angular vehicle responses and the occupant impact velocities according to

the procedures presented in NCHRP 230 ( 1). These results were compared

with analogous results for the New Jersey CMB. Based on these comparisons

it was determined that the single-slope CMB should induce approximately the

same vehicle response as achieved with the New Jersey CMB.

Complete fabrication drawings for the single-slope barrier are

presented in Figure 38 of Appendix A. As shown in Appendix A, it is

recommended that· the single-slope CMB ·be fabricated in 30 ft {9.1 m)

lengths. As shown in the fabrication drawings, two steel pipes are

embedded in the barrier segments approximately at the quarter points. The

procedure for lifting the barrier involves the insertion of solid steel

bars through the lifting pipes. Then chains can be draped around the

lifting ·bars and the barrier can be moved with either two pieces of light

lifting equipment such as fork lifts or a single piece of heavier lifting

equipment. In the current project the barrier segments were moved with two

fork lifts with approximately the same ease as moving similar 30 ft {9.1 m)

segments of the New Jersey CMB.

9

The ends of the single-slope CMB segments are equipped with provisions

for two different types of connections. The first type of connection

involves the use of external steel angles which are attached to the barrier

segment ends with specially fabricated bolts as shown in Figure 5 and in

the fabrication drawings presented in Figure 38 of Appendix A. This angle-

sp lice connection is recommended for temporary connections and is not

required when the barrier is installed in the permanent configuration.

The second connection deta i 1 involves a slot which is cast into both

ends of the barrier segments. A permanent connection is made by inserting

a reinforcing bar grid into the slots of both ends of mating barrier

segments and filling the slots and the space between the barrier ends with

grout. The grout used in this research consisted of a mixture of 1 part

cement and 2 parts sand, with water added to make a workable mix. The

permanent installation is completed by locking the barrier segment into

place with a minimum of 1 in (2.54 cm) of asphalt overlay placed next to

both faces of the barrier as shown in Figure 6. An alternative temporary

connection can be accomplished by simply inserting the reinforcing bar grid

into the slots without using the grout. While this temporary connection is

not as strong as the angle-splice connection it has been shown to be

adequate.

The barrier segments tested in this project were fabricated with

reinforcing bar placed as shown in Appendix A. Subsequent to the tests.

reported herein, an alternate reinforcing detail for the single-slope CMB

was developed. The alternate reinforcing scheme incorporates wire mesh in

the single-slope CMB away from the barrier ends as shown in Figure 39 in

Appendix A. It is recommended that the reinforcing bar detail contained in the original fabrication drawings presented in Figure 38 be continued for a total distance of at least 2 ft (0.60 m) from each end of the barrier segment with adequate a 11 owance provided for development lengths so that

the barrier will behave as though it is continuously reinforced.

10

. . !,_ -·.· ~ :~ .. ·,·~.". ;·. ~i-."!'>• ··..; - ..w;

gjlf-

Slngle Slope CMB

1 In. Asphalt Overlay

\Asphalt Subbase

Figure 6. Typical cross-section of permanently installed single-slope CMB

12

FULL-SCALE CRASH TESTS

Four full-scale crash tests were conducted on the single-slope CMB to

eva 1 uate its performance with respect to structural adequacy, occupant

risk, and vehicle exit trajectory. The first test involved a 4,500-lb

(2,043 kg) full-size automobile which impacted the single-slope CMB in a

temporary configuration. The second and third tests involved a 4,500-lb (2,043 kg) full-size automobile and a 1,800-lb (817 kg) subcompact automobile, respectively. The vehicles in the second and third tests impacted the single-slope CMB in the permanent configuration. The fourth

test involved a 4,500-lb (2,043 kg) full-size automobile which impa.cted the single-slope CMB in a temporary configuration.

The first three full-scale crash tests were conducted using four 30-ft

{9.1 m) single-slope CMB segments connected together to form a 120-ft

(36.4 m) longitudinal barrier. The fourth full-scale crash test was

conducted using six 30-ft (9.1 m) CMB segments for an overall length of 180 ft (54.6 m).

The barrier segments in the temporary barrier confi gurat i ans were

.positioned on an existing concrete surface at the TTI test track. In the

first crash test, the four barrier segments were joined with the angle-

spl ice temporary barrier connection without the reinforcing bar grid. In

the fourth crash test, the barrier segments were joined with the ungrouted

reinforcing bar temporary barrier connection. In both temporary

configurations, the single-slope CMB was not attached to the roadway surface. These installations represent typical temporary installations.

The four 30-ft (9.1 m) barrier segments in the permanent barrier configuration were positioned on a specially prepared subbase consisting of

2 in (5.1 cm) of type D hot mix asphalt which was pl aced on top of 4 in

(10.2 cm) of compacted crushed limestone. The subbase was prepared in an

area immediately adjacent to the concrete test track. The subbase area was

13

approximately 125 ft {37.9 m) long and 8 ft {2.4 m) wide as shown in Figure

7.

The four barrier segments were a 1 i gned on the. subbase such that the

impact surface of the barrier was set back approximately 1 ft { .3 m) from

the front of the subbase as shown in Figure 7. Then, the reinforcing bar

grids were put into the slots at the ends of the barri~r segments. Next,

another 1 in (2.54 cm) of typ:e D hot mix asphalt was added to the subbase

in front of the barrier and behind the barrier. This final application of

asphalt resulted in a 1 ft (.3 m) wide addition of asphalt on the impact side of the barrier and a 5 ft {1.5 m) wide addition of asphalt on the

opposite side of the barrier as shown in Figure 7. Finally, the barrier

slots, the gap b.etween the barrier segment ends, and the angle-splice

tnsets on the ends of the barrier were all grouted with a mixture of one

part sand and two parts cement. The grout was applied so that the 120-ft

(36. 4 m) barrier had the appearance of a continuous barrier. The use of

the angle-splice connection in the permanent configuration is optional. It

was not used in the permanent installation described in this report.

In all of the full-scale crash tests, the vehicle impacted the

longitudinal barrier at a point approximately 5 ft (1.5 m) upstream of the

middle barrier segment joint. This impact location was chosen to provide

· the most cri ti ca 1 impact situation with respect to both strength and

snaggi.ng. Test statistics fo.r the four crash tests rire summarized in Table.

1. Sequential photographs of the tests are presented in Appendix B.

Accelerometer traces and plots of roll, pitch, and yaw are presented in

Appendix C.

RESULTS FROM TEST 9429C-l

In this test, a 1980 Cadillac Sedan DeVille was directed into the

single-slope CMB deployed in a temporary configuration with the angle-

spl ice connection. Figures 8 and 9 show the vehicle prior to the impact.

14

..... U'I

Figure 7. Permanent single-slop CMS installation

...... m

Test No.

Vehicle Weight, 1 b (kg)

Impact Speed, mi/h (km/hr)

Exit Angle, degrees

Impact Angle, degrees

Displacement, in (cm)

Occupant Impact Velocity ft/s (m/s)

Longitudinal Lateral

Occupant Ridedown Acceleration g's

Longitudinal Lateral

Vehicle Damage Classification TAD CDC

Table 1. Summary of crash test results

9429C-1 9429C-2

4500(2043) 1800(817)

60.3(97.0) 60.7(97.70)

0.5 4.3

15.2 19.9

7.0(17.8) 0.0(0.0)

14.4(4.4) 15.7(4.8) 17.6(5.4) 27.7(8.4)

-2.5 -2.3 -7.7 -9.2

11LFQ4 llLFQS 11FLEK2& 11LFEW3 11LFEW3

9429C-3 9429K-1 ------

4500.( 2043) 4500(2043)

63.1(101.5) 62.0(99.8)

8.5 3.5

26.5 15.1

0.0(0.0) 6.0(15.2)

22.1(6.7) 16.3(5.0) 28.9(8.8) 18.4(5.6)

-4.2 -3.2 -10.7 -6.2

11LFQ5 11FLQ4 11LFAW3 11FLEK2&

llLFEWl

Figure 8. Vehicle before test 9429C-l.

17

Figure 9. Vehicle/barrier geometrics for test 9429C-l.

18

The vehicle was propelled into the barrier using a reverse tow and guidance

system. Figure 10 presents the temporary barrier prior to the impact. The

test inertia mass of the vehicle was 4,500 lb (2,043 kg). The height to

the 1 ower edge of the vehi c 1 e bumper was 12. 5 in ( 31. 8 cm) and it was

21.0 in (53.3 cm) to the top of the bumper. Other dimensions and

information on the test vehicle are presented in Figure 11. The vehicle

was free-wheeling and unrestrained just prior to the impact.

The speed of the vehicle at impact was 60.3 mi/h (97.0 km/h) and the

angle of impact was 15.2 degrees. The vehicle impacted the barrier

approximately 55 ft (16.8 m) from the upstream end of the barrier. The

left front wheel of the vehicle made contact with the barrier at

approximately 0.029 seconds after impact and shortly thereafter the tire

began to ride up the face of the barrier. The vehicle began to redirect at

0.049 seconds. At about 0.160 seconds, the rear of the vehicle struck the barrier and by 0.173 seconds the vehicle was traveling parallel to the

barrier at a speed of 51.9 mi/h (83.5 km/h). The vehicle lost contact with

the barrier at 0.462 seconds traveling at a velocity of 51.3 mi/h

(82.5 km/h) and with an -angle of 0.5 degrees away from the barrier. The

brakes were then applied and the vehicle yawed in a counter-clockwise

direction and subsequently came to rest 240 ft {73 m) from the point of

impact. Sequential photographs of the impact are shown in Figure 40 in Appendix B.

As shown in Figures 12 and 13, the barrier received only minimal

cosmetic damage. There were ti re marks on the face of the barrier to a

maximum height of 31 in {79 cm). The bumper scraped the barrier at a

height of 42 in (107 cm). The vehicle was in contact with the barrier for 17 ft (5.2 m). The maximum lateral movement of the barrier was 7 in

(17.8 cm) at the middle joint of the barrier.

The vehicle sustained moderate damage to the left side as shown in

Figures 14 and 15. Maximum crush at the left front corner at bumper height

19

Figure 1 O. Barrier before test 9429C-l~

20

Date: __ 1_1_·-_2_1_-_88_· __ Test No. : _ __,._9_42_9_C_-_l __ VIN: 6069A915850

Make: __ c.;.;a::..;:d....,i .... 1 ..... 1-=a-=c- Model: Sedan DeYi 1 le Year: 1980 Odometer~ 1-05688 ---------Tire Size: P225 75Rl5 Ply Rating: 4 ------ Bias Ply: _ Belted: Radial: X

Tire dia------~~ Accelerometers ~.Jheel dia ___ ....._..,.

j g

h

c

f

4-wheel weight for e.g. det. tf 1162 rf 1257 .t.r 1032 rr 1049

Mass - pounds Curb Test Inertial Gross Static

Ml 2368 2419

M2 1799 2081

MT 4159. 4500

Note any damage to vehicle prior to test:

*d = overall height of vehicle .

Tire Condition: good ~ fair x -

badly worn_

Vehicle Geometry - inches

a 77 .25 'b 42.0

c 121.25 Q* 56.75

e 57.0 f 220.25

9 h 56 .1

j 34.0

k 19.0 l 39.0

m 2] .0 n 5.0

0 12.5 p 61.0

r 2715 s 16125

Engine Type: ___ v_a __ _ Engine CID: 5.7 liter Transmission Type:

Automatic or Manual FWD or RWD or 4WD

Body Type: 4 door Steer"ing Column Col lapse

Mechanism:

Behindwheel units -Convoluted tube -Cylindrical mesh units -Embedded ba 11 -NOT collapsible

Other energy absorption _Unknown

Brakes:

Front: discL drum_

Rear: disc drum.25._

Figure 11. Test vehicle properties for test 9429C-1

21

Fi qure 12. Barrier after test 9429C-l.

22

Figure 13. Barrier movement after test 9429C-l.

23

~~;·~·· .. ..... 'I

· . ..,,.

Fiqure 14. Vehicle after test 9429C-l.

24

Figure 15. Damage to left rear of vehicle for test 9429-1

25

was 12.0 in (30.7 cm). The left front rim was bent and the tire damaged. There was damage to the hood, grill, bumper, left front quarter panel, the left front ?lnd rear doors, the left rear quarter panel and the rear bumper.

As stated previously, the impact speed was 60.3 mi/h (97 .0 km/h) and the angle of impact was 15.2 degrees. The vehicle lost contact with the barrier traveling at 51.3 mi/h (82.5 km/h) and 0.5 degrees. NCHRP 230 describes occupant risk evaluation criteria and places limits on these for acceptable performance for tests conducted with 1,800 lb-(817 kg) vehicles (1). These limits do not apply to tests conducted with 4,500-lb (2,043 kg) vehic 1 es but were computed and reported for info.rmat ion on 1 y. The occupant impact velocity was 14.4 ft/s {4.4 m/s) in the longitudinal direction and 17.6 ft/s (65.4 m/s) in the lateral direction. The highest 0.010 second occupant ridedown accelerations were -2.5 g (longitudinal) and -7.7 g (1atera1). These data and other pertinent i nformatton from the test are summarized in Figure 16.

Vehicular angular displacements are displayed in Figure 44 of Appendix B. Vehicular accelerations versus ti me traces filtered at 300 Hz are presented in Figures 45 through 47 in Appendix C. These data were further analyzed to obtain the 0.050 second average accelerations. The maximum 0.050 second average accelerations measured near the vehicle center-of-gravity were -3.3 g (longitudinal) and -6.8 g (lateral).

These test results show that the barrier contained and smoothly redirected the test vehicle with 1 ittle lateral movement of the barrier. There was no intrusion into the occupant compartment and minimal deformation of the occupant compartment. The vehicle remained upright and relatively stable during the collision. The vehicle trajectory at loss of contact indicates minimum intrusion into the adjacent traffic lanes.

26

0.000 s

r-a •n-4

42 In

!-•.,--! J.-•"':!T r-241n

0 .127 s 0.254 s 0.381 s

Test No ........ 9429C-l Date ......•.. 11/22/88 Test Installation Single Slope

Concrete Barrier Installation Length .. 120 ft (36.6 m) Vehicle ....... 1980 Cadillac

Sedan DeVille Vehicle Weight

Test Inertia .... 4,500 lb {2,043. kg) Vehicle Damage Classification

TAD ........ 11LFQ4 CDC •....... 11FLEK2 & lllfEW3

Maximum Vehicle Crush. 12.0 in {30.5 cm) Max. Barrier Movement. 7.0 in {17~8 cm)

Impact Speed •.. 60.3 mi/h (97.0 km/h) Impact Angle .•• 15~2 deg Ex it S.peed. • . . 5 L 3 ( 82 . 5 km/h) Exit Trajectory . 0.5 deg Vehicle Accel~rations

(Max. 0.050-sec Avg) Longitudinal .• -3.3 g Lateral ...• -6.8 g

Occupant Impact Velocity Longitudi na 1. . 14. 4 ft/s ( 4. 4 m/s) Lateral . . . . 17 . 6 ft/ s ( 5 . 4 m/ s )

Occupant Ridedown Accelerations· Longitudinal .. -2.5 g Lateral .... -7. 7 g

Figure 16. Summary of results for test 9429C-l.

RESULTS FROM TEST 9429C--2

In this test, a 1980 Honda Civic was dire~ted into the single-slope barrier dep 1 oyed in a permanent configuration using a reverse tow and

guidance system. Figure 17 presents the vehicle prior to the impact.

Figures 18 and 19 show the single-slope CMB in the permanent configuration prior to the impact. The test inertia mass of the veh i c 1 e was 1, 800 lb (817 kg). The height to the lower edge of the vehicle bumper was 13.5 in

(34.3 cm) and it was 18.5 in (47 .0 cm) to the top of the bumper. Other

dimensions and information on the test vehicle are given in Figure 20. The vehicle was free wheeling and unrestrained just prior tn impact.

The speed of. the vehicle at impact was 60. 7 mi/h (97. 7 km/h) and the angle of impact was 19.9 degrees. The vehicle impacted the barrier approximately 55 ft (16.7 m) from the upstream end of the barrier. The left front wheel made 'Contact with the barrier at approximately 0.016 seconds after impact and shortly thereafter the tire began to be pushed up

the face of the barrier. The vehicle began to redirect at 0.034 seconds and at 0.076 seconds the left front tire aired out. By 0.129 seconds, the vehicle was traveling parallel with the barrier and at about 0.134 seconds the rear of the vehicle struck the barrier. The vehicle lost contact with

the barrier at 0.273 seconds traveling at 52.1 mi/h (83.8 km/h) and 4.3 degrees away from the barrier. The brakes were then app 1 i ed and the

vehicle subsequently came to rest 160 ft (49 m) from the po,int of impact.

Sequential photographs of this test are shown in Figure 41 of Appendix B.

As shown in Figure 21, the barrier received minimal cosmetic damage.

There were tire marks on the face of the barrier to a maximum height of 24 in (61 cm). The bumper scraped the barrier at a height of 30 in (776 cm) and there were sheet metal scrapings at 35 in (89 cm). The vehicle was in contact with the barrier for 9.5 ft (2.9 m). There was no discernible

movement of the barrier.

28

..... ~, .... .-,.

Figure 18. Test installation before test 9429C-2 (impact side).

30

Figure l 9o Test installation before test 9429C-2 {rear side).

31

Date: ____ 1_2-_0....,...5_-_88 __ _ Test No. : ______ 94.;;..;;9~2--..C_..-2...__ __ VIN: 5L-Cl034430

Make: __ H_o ___ nd_a_· __ _ Mode 1 : ___ C.....,.i ....... v l ....... · c _____ _ Year: 1980 Odometer: 59391

Tire Size: . P155/80R12 Ply Rating_: __ 3 __ _ Bias Ply: _ Belted: Radial: x

Accelerometers

f f a p

L_

Ti re di a-------+oiE~ .. Accelerometers

Wheel dia---..+-+-~

j

f

4-wheel· weight for e.g. det. lf 587 rf 558 lr 325 rr 330


1,145

655

1,800


*d = overall height of vehicle

Ti re Condition: good _ fair x

badly worn_


a 62. 25

c 0 88.25

e 28.75 9 ___ ___

k 15.5 --------m 18. 5

0 13. 5 ------r 21. 25

b

d*

f

h

j

l

n

p

s

29.0

51.75

146.0

32. 1

28.5

28.0

4.5

54.0

13.25

Engine Type: 4 cylinder

Engine CID: -------Transmission Type:

Automatic or Manual FWD or RWD or 4WD

Body Type: 2-door Hatch Steering Column Collapse

Mechanism: Behind wheel units

-Convoluted tube -Cylindrical mesh units -Embedded ba 11

NOT collapsible Other energy absorption

-Unknown

Brakes: Front: disc~ drum_ Rear: disc drum_x_


32

Figure 21 c Barrier after test 9429C-2.

33

The vehicle sustained moderate damage to the left side as shown in

Figure 22. Maximum crush at the left front corner at bumper height was 7.0

in (17 .8 cm):. The left front and rear struts were damaged, the 1 eft front

rim was bent, and the tire was damaged. There was damage to the hood,

grill, front bumper, left front quarter panel, the left door, the left rear

quarter panel and the rear bumper.

As stated previously, the impact speed was 60.7 mi/h (97.7 km/h) and

the angle of impact was 19.9 degrees. The vehicle lost contact with the

barrier traveling at 52.1 mi/h (83.8 km/h) and with an angle of 4.3

degrees with the barrier. NCHRP 230 describes occupant risk eva 1 uat ion criteria and places limits on these for acceptable performance for tests

conducted with 1,800-lb (817 kg} vehicles impacting longitudinal barriers

with a speeds of 60 mph (96 km/h) and angles of 15 degrees (1). These

limits do not apply to this particular test because the impact angle was 20

degrees. However, these limits were computed and reported for information

purposes only. The occupant impact velocity was 15.7 ft/s (4.8 m/s} in the

longitudinal direction and 27.7 ft/s (8.4 m/s) in the lateral direction.

The highest 0.010 second occupant ridedown accelerations were -2.3 g

(longitudinal) and -9.2 g (lateral}. These data and other pertinent

information from the test are summarized in Figure 23.

Vehicle angular displacements are displayed in Figure 48 in Appendix

B. ·Vehicular accelerations versus time traces filtered at 300 Hz are

p.resented in Figures 49 through 51 in Appendix B. These data were further

analyzed to obtain 0.050 second average accelerations versus time. The

maximum 0.050 second averages measured at the center-of-gravity were -6.5 g

(longitudinal) and -15.3 g (lateral).

The barrier contained and smoothly redirected the test vehicle with no

lateral movement of the barrier. There was minimal intrusion into the

occupant compartment and minimal deformation of the cpmpartment. The

vehicle remained upright and relatively stable during the collision. The

34

,/·

Figure 22. Vehicle after test 9429C-2.

35

0.000 s 0.073 s

Test No. . . • . . . . 9429C-2 Date • • . . . . . . . 12/05/88 Test Installation Single Slope

Concrete Barrier I nsta 1 lat i of) Length. . 120 ft (36. 6 m) Vehicle . • • • 1980 Honda

Civic Vehicle Weight

Test Inertia .... 1,800 lb (817 kg) Vehicle Damage Classification

TAD ........ lllFQS CDC ••••..•• 11LFEW3

Maximum Vehicle Crush. 7.0 in (17.8 cm)

0.146 s 0.248 s

Impact Speed. 60. 7 mi/h (97. 7 km/h) Impact Angle ... 19.9 deg Exit Speed. • • • 52 .1 (83 .8 km/h) Exit Trajectory . 4.3 deg Vehicle Accelerations

(Max. 0.050-sec Avg) Longi tudi na l. . -6. 5 g Lateral .... -15.3 g

Occupant Impact Velocity Longitudinal; . 15.7 ft/s (4.8 m/s) Lateral .... 27 .7 ft/s (8.4 m/s)

Occupant Ridedown Accelerations longitudinal •. -2.3 g Lateral .... -9.2 g

Figure 23.. Summary of results for test 9429C-2.

vehicle trajectory at the loss of contact indicates minimum intrusion into

adjacent traffic lanes with the change in velocity being within recommended

NCHRP limits for a 15 degree impact. The longitudinal occupant/compartment

impact velocity was within the limit recommended in NCHRP 230 for 15degree

impacts. The lateral impact velocity exceeded the recommended NCHRP 230

limit for 15 degree impacts. However, the lateral impact velocity was less

than the limiting value presented fn NCHRP 230 and is consistent with the

performance of other vehicles impacting rigid barriers under similar

conditions (7 ,8). It should also be noted that new impact performance

standards are currently being considered to replace the current NCHRP 230

criteria (9). Finally, comparisons of the current tests with similar tests

conducted on New Jersey barriers show that the vehicle redirection with the

new single-slope barrier is more stable than similar impacts with the New

Jersey shape barriers.

RESULTS FROM TEST 9429C-3

This test involved the impact of a 1979 Caddil ac Sedan deVil le as

shown in Figure 24. The vehicle was directed into the barrier using a

reverse tow and guidance system. Figure 25 presents the single-slope

barrier prior to the impact. The barrier shown in Figure 25 is the same

barrier used in the previous test with paint added for cosmetic purposes.

The test inertia mass of the vehicle was 4,500 lb {2,043 kg). The height

to the lower edge· of the vehicle bumper·was 12.0 in (30.5 cm) ·and it was

23.0 in {58.4 cm) to the top of the bumper. Other dimensions and

information on the test vehicle are presented in Figure 26. The vehicle

was free-wheeling and unrestrained just prior to impact.

The speed of the vehicle at impact was 63.1 mi/h (101.5 km/h) and the

angle of impact was 26.5 degrees. The vehicle impacted the barrier

approximately 54 ft (16.5 m) from the upstream end of the barrier. The

1 eft front wheel made contact with the barrier at approximately 0. 024

seconds after impact and shortly thereafter the tire began to be pushed up

37

.. c .~FW _: . .:;;;; :--:::.:s

~-· . .• ~·-

- . -- . - ::. ·-·· .... - ... : ... _ ., _, .. ·. ~

'\.. i:· ~· ... -_ ....

.. ·-~~;;_~;.·~ ·: :-,'..: .. ·. ~ ... ,

~ ~·:;.o.:·-.;.:-.:·';J .• !·t·~~.=~;.: .. 1-:. " ;

;.

- --·~

.·

Figure 24. Vehicle before test 9429C-3.

38

·.~

·· .. ~·.

a rft --- . •L-1-«.t:t..._...__._._ .... ___ .... --~ -~ .... ....._.. .......... ......._.,,__ .. ~ . ..;:;... .. _._. --·· - ·"--·-~-·

Rear of barrier

.....

--· ~ .- ~ .~··

... _. ~·;..·.

Impact side

Figure 25. Barrier before test 9429C-3.

39

.:

Date: Test No.: 9429C-3 6D6959C360077 ------- --~----Cadillac Make: ------ Odometer: 136868

Tire Size: P235/75Rl5 Ply Rating: _..-.2 __ _ Bias Ply: _ Belted: Radial: _x_

Tire dia ---~~

~~heel dia --.--~.----

j

4-wheel weight

· Acee 1 erometers

Accelerometers

f

for e.g. det. lf 1,175 rf 1,291 tr l,041 rr 990


Ml 2,415 2,469

M2 1,720 21 031

MT 4,135 42500


Cracked windshield - driver's side

*d = overall height ·of vehicle

Tire Condition: good _ fair~

badly worn_

Vehicle Geometry .. inches

ct 76.0 - b 43.5

c 121.25 c;I* 59 .. 0

e 56.0 f 220. 75 g ___ _

k 21.5 _ ___. .............. .,.....__ m 23.0 ----0 12.0 ----r __ 2_8_ ...... 5 ____

h 54.7

j 36.0

l 39.0

n __ 5_.o __

p 62.5

s 16. 25

Engine Type: V-8 ------Engine CID: 7~0 litre Transmission Type: . Automatic or Manual

FWD or RWD or 4WD Body Type: 4•door

Steering Column Collapse Mechanism:

Behind wheel units -Convoluted tube -. ·Cylindrical mesh units -Embedded ba 11

NOT collapsible _Other energy absorption _Unknown

Brakes: · Front: disc~ drum_ Rear: disc_· drum x


40

the face of the barrier. The vehicle beg.an to redirect at 0.034 seconds

and at about 0.171 seconds the rear of the veMcle struck the barrier. The

left side of the vehicle became airborne at 0.188 seconds. By 0.198

seconds the vehicle was traveling parallel with the barrier at a speed of

53.2 mi/h {85.6 km/h). The vehicle became completely airborne at 0.295

seco.nds. While st i 11 airborne, the vehicle lost contact with the barrier

at 0.360 seconds traveling at SL8 mi/h (83.3 km/h) and 8.5 degrees away

from the barrier. The right front tire touched ground at 0. 726 seconds

after i mpa.ct. The brakes were then applied and the vehicle subsequently came to rest 165 ft ( 5·0 m) from the point of impact. -Se.quent i al

photographs of this test are presented in Figure 42 in Appendix B.

As shown in Figure 27, the barrier received minimal cosmetic damage.

There were tire marks on the face of the barrier to a maximum height of 34

in (86 cm). The- bumper scraped the barrier at a height of 4-0 in (102 cm) and there were sheet metal scrapings to the top of the barrier. Examinations of the high speed movies and direct measurements of the

markings on the barrier shown that the center of the automobile wheel hub

rose to a height of 26 to 30 in (66 to 76 cm) before losing contact with the barrier. The vehicle was in contact with the barrier for 13 ft (4 m).

There was no discernible movement of the barrier.

The vehicle sustained seve:re damage to the left side as shown in· Figures 28 and 29. Maximum crush at the left front corner at bumper height

. .

was 12. 0 in (30. 5. cm). The floorpan and subframe were bent and the 1 eft

side of the rear axle was damaged. The left front rim was bent and the

ti re was damaged. There was damage to the hood, g·ril 1, radiator and fan,

front bumper, left front quarter panel , the left front and rear doors, the

1 eft rear quarter panel, and the rear bum.per. The right front quarter

panel was bent when the front of the vehicle shifted to the right about

Sin (13 cm).

41

- 1-.·~-· -·-

Figure 27" Barri er after test 9429C-3.

42

.......... -:-- --........

: ....... :i,-.

. -~ ':"- -

Figure 280 Vehicle after test 9429C-3.

43

Figure 29.

Left rear tire

Left front tire

Damage to tires on left side for test 9429C-3

44

As stated previously, the impact speed was 63.1 mi/h (101.5 km/h) and

the angle of impact was 26.5 degrees. The vehicle lost contact with the

barrier traveling at 51.8 mi/h (83.3 km/h) and 8.5 degrees. NCHRP 230

describes occupant risk criteria and places limits on these for acceptable

performance for tests involving 1,800-lb (817 kg) impacting at 15 degrees

with a velocity of 60 mph (96 km/h) (1). These 1 imits do not apply to

tests involving 4,500-lb automobiles impacting at 25 degree angles but were

computed and reported for information only. The occupant impact velocity

was 22.1 ft/s (6.7 m/s) in the longitudinal direction and 28.9 ft/s

(8.8 m/s) in the lateral direction. The highest 0.010 second occupant

ridedown accelerations were -4.2 g (longitudinal) and -10.7 g (lateral).

These data and other pertinent information from the test are summarized in

Figure 30.

Vehicular angular displacements are displayed in Figure 52 in

Appendix 8. Vehicular accelerations versus time traces filtered at 300 Hz

are presented in Figures 53 through 55. These data were further analyzed

to obtain 0.050 second average accelerations versus time. The maximum

0.050 second average accelerations measured near the vehicle center of

gravity were -6.4 g (longitudinal) and -13.l g (lateral).

The barrier contained and smoothly redirected the test vehicle with no

1atera1 movement of the barrier. There was some deformation of the

·occupant compartment. · However, there was ·minimal intrusion into the

occupant compartment. The vehicle remained upright and relatively stable

during the collision. The vehicle trajectory at loss of contact indicates

minimum intrusion into adjacent traffic lanes and the change in velocity

was within the recommended limit set forth in NCHRP 230 {l).

It should be noted when interpreting the data associated with this

test that both the velocity and and impact angle associated with this test

were higher than required by NCHRP 230 (1). The following formula

presented in NCHRP 230 allows the impact severity, IS, of impacts to be

45

0.000 s .... ..,,,.... ' ,,..:r~ ' ·,.

•. A. . . ... . (' ___ ...... ·.:· .;~~/' ~· - ""

... -- ..... -0.120 s

·'tf"":··->

........ ... ~:;..;·.-(° ;--..... ............ ,. ....

0.240 s 0.363 s

,llfi'r: -... ~. ,'

Impact Speed. . . 63. I rni/h ( 101. 5 km/h) Impact Angle ... 26.5 deg Exit Speed .... 51.8 (83.3 km/h} Exit Traje·ctory . 8. 5 deg Vehicl~ Accelerations

(Max. 0.050-sec Avg) Longitudinal .. -6.4 g Lateral .... -13.1 g

Occupant Impact Velocity Long i tud i na 1. . 2 2 • 1 ft/ s ( 6 . 7 m/ s } Lateral .... 28.9 ft/s (8.8 m/s)

Occupant Ridedown Accelerations Longitudinal .. -4~Z g Lateral .... -10.7 g

Figure 300 Summary of results for test 9429C-3.

quantified in terms of impact velocity, V; vehicle mass, m; and impact angle,

a.

IS = 1/2 m v2 (sin a)2 (1)

The impact severity calculated for the actual test conditions is

approximately 25 percent greater than the intended impact severity

associated with a 4,500-lb (2,043 kg)/60 mph (96 km/h)/25 degree impact.

This deviation suggests that the impact force between the barrier and the

vehicle would be approximately 25 percent greater than would have been the

case at the intended condittons. Thi~ additional impact force resulted in

a more severe impact than required under NCHRP 230. Despite the increased

severity of this .impact the vehicle was smoothly redirected and remained

upright throughout the test.

RESULTS FROM TEST 9429K-l

In this test, a 1981 Pontiac Bonneville was directed into the single-

sl ope CMB deployed in a temporary configuration with the ungrouted reinforcing bar grid connection. Figures 31 and 32 show the vehicle prior

to the impact. The vehicle was propelled into the barrier using a reverse

tow and guidance system. The barrier segments used in thts test were the

same barrier segments used in the previous tests. The reinforcing bar

grids which were grouted into the barriers during the permanent

configuration were removed by drilling and chipping. Figure 33 presents

the barrier prior to the impact. The test· inertia mass of the vehicle was

4,500 lb (2,043 kg). The height to the lower edge of the vehicle bumper

was 10.5 in (26.7 cm) and it was 19.5 in (49.5 cm) to the top of the

bumper. Other dimensions and information on the vehicle are presented in

Figure 34. The vehicle was free-wheeling and unrestrained just prior to

the impact.

47

Figure 31. Vehicle/barrier geometrics for test 9429K-l.

48

.. _..... .,L __ ...---.--t- . -·

----... __ o:::-_,_c:;:-: ••• ..; •• ,

.-. •. ;,"· . " , .... ......

-" · ... ,,.

. -. { ·~:·~--)t.-~~ .. ;.~::£fr>' -

. .. . ·.-:. :: "'.. ·" .. : ~- ·; ~ .. ~.:...;_ •. _.; .

. -· ... -:-· __ ., __ -;;:- ··> .... -. ::~r-;. ~'. :~ · •.

Figure 32. Vehicle before test 9429K-l.

49

az

Figure

.,., : ..

...... - _ ..

~-~ .. --------~··-------

33. Barrier before test 9429K-1.

50

'•

Date: 04-27-89 Test No.: 9429K-1 VIN! 2G2AN69N2B1754097

Make: GM Pontiac Model: Bonneville Year: 1981 Odometer: 69,785

Tire Siie: P205/75Rl5 Ply Rating: _4 _____ _ Bi as Ply: _ Belted: Radial: ..x_

Height: 26 11

-----152-3/411 ~ Tire dia ------~-.i Accelerometers

ilhee l di a ___ ,___

j

c

f

4-wheel weight , for e.g. det. £.f 1308 rf 1214 ir 988 rr 990

Mass .;.. pounds Curb Test Inertial Gross Static

Ml 2379 2522

Mz 1605 1978 MT 3984 4500


*d = overall height of vehicle

Tire Condition: good_ fair _x_

badly worn -·


a 74 11 .b 40"

c 115 11 ~* 56"

e 54 11 f 209 11

g h 50.5 11

i j 31.5"

k 19 11 .e. 33-3L4"

m 1912" n 4~"

0 lO!a" p 61~"

r 27 11 s 16~"

Engine Type: V-8 Diesel Engine CID: 350 -----Transmission Type:

Automatic X«~X*»~M~X XXWllXmt' RWD )OO{X)tKOC

Body Type: 4-door Steering Column Collapse

Mechanism! · Behind wheel units

-Convoluted tube -Cylindrical mesh units -Embedded ba 11 -NOT collapsible -Other energy absorption -Unknown

Brakes: Front: disc_x_ drum_. Rear: disc drum X

Figure 34. Test vehicle properties for test 9429K-1.

51

The speed of the vehi c 1 e at impact was 62. O mi/h { 99. 8 km/h) and the angle of impact was 15.1 degrees. The vehicle impacted the barrier approximately 85 ft (26.0 m) from the upstream end of the barrier. Upon

impact, the left front of the vehicle began to deform and shortly

thereafter, the left front of the vehicle began to climb up the face of the

barrier. At app¥'oximately 0.042 seconds after the impact, the vehicle

began to redirect and by 0.173 seconds, the rear of the vehicle had .

contacted the barrier. The vehicle traveled parallel to the barrier at

. 57.3 mi/h (92.2 km/h{). Shortly thereafter, the vehicle lost contact with

the barrier at approximately 0.307 seconds after impact. The exit speed

was 57. 0 mi/h (91. 7 km/h) with an exit angle of 3. 5 degrees. As the

vehicle exited the barrier, the brakes were applied. The vehicle then

yawed counter-clockwise and came to rest approximately 240.0 ft {73.2 m)

from the point of impact. Sequent i a 1 photographs of the imp act are shown

in Figure 43 in Appendix a.

As shown in Figure 35, the barrier received only minimal cosmetic

damage. The barrier was displaced laterally a maximum distance of 6.0 in

{15.2 cm) at the joint closest to the impact point. The maximum height of vehicle-rail interaction was 32 in {81.3 cm). The vehicle was in contact

with the barrier for a total length of 16.0 ft {2.4 m). Further~ it should

be noted that the barrier segments at the impact joint experienced relative

lateral movement as shown in Figure 35. This relative lateral movement

caused the impacting vehicle to be subjected to an abrupt. change in the

barrier face. Prior to the conducting this test, there was a question as

to whether or not this relative lateral movement of the barrier ends.would

be sufficient to cause the vehicle to snag. However, as evidenced by the

test results, the vehicle was successfully redirected.

The vehicle received minor damage as shown in Figure 36. The maximum

crush was 8.0 in (20.3 cm) at the left front corner of the vehicle. The left control arm, wheel, fender, and hood were severely b~nt. In addition,

52

• .. . f, ..... ' ... . ' : ..

... l ..

...&.·

......... -

Figure 35. Barrier after test 9429K-1.

53

Figure 36. Vehicle after test 9429K-l.

54

the left wheel was pushed rearward 1.0 in (2.5 cm} and the rear axle was

bent. The entire left side of the vehicle was dented and scraped.

As stated previously, the impact speed was 62.0 mi/h (99.8 km/h} and

the impact angle was 15.l degrees. The vehicle lost contact with the

barrier with a speed of 57.0 mi/h (91.7 km/h} with an exit angle of 3.5

degrees. NCHRP 230 describes occupant risk evaluation criteria and places

limits on these for acceptable performance for tests conducted with 1, 800

lb (817 kg) vehicles (1). These limits do not apply to tests conducted

with 4,500 lb (2.043 kg} vehicles but were computed and reported for

information only. The occupant impact velocity was 16.3 ft/s (5.0 m/s) in

the longitudinal direction and 18.4 ft/s (5.6 m/s) in the lateral direction. The highest 0.010 second occupant ridedown accelerations were

-3.2 g (longitudinal) and -6.2 g (lateral). These data and other pertinent

information from the test are summarized in Figure 37.

Vehicle angular displacements are displayed in Figure 56 of Appendix

B. Ve hi cul ar acce 1 erat ions versus time traces filtered at 300 Hz are

presented in Figures 57 through 59 in Appendix C. These data were further

analyzed to obtain the 0.050 second average accelerations. The maximum

0.050 second average accelerations measured near the vehicle center-of-

gravity· were -5.3 g (longitudinal) and -7.3 g (lateral).

· These test results show that the barrier · contained and smoothly

redirected the test vehicle with little lateral movement of the barrier.

There was minimal damage to the barrier and the vehicle. There was no

debris or detached elements. There was minimal deformation and intrusion

into the occupant compartment. The vehicle remained upright and stable

during the initial test period and after leaving the barrier. The vehicle

trajectory at loss of contact indicates minimal intrusion into the adjacent

traffic lanes.

55

J+-e •n-1

42 In

0.000 s 0.099 s

Test No •...... 9429K-1 Date . . . . 04/27/89 Test Installation .. Stngle Slope Concrete

Median Barrier Install at ion Length . 180 ft ( 54. 9 m) Vehicle . . . . . 1981 Pontiac

Bonneville Vehicle Weight

Test Inertia 4,500 lb (2,043 kg) Vehicle Damage Classification

TAD ......... 11FLQ4 4 '" CDC . . . . . . . . 11 FLEK2 & 11 LFEWI

__ _j_ Maximum Vehicle Crush 8.0 in (20.3 cm) Maximum Barrier

0 .198 s 0.307 s

Impact Speed ..•. 62.0 mi/h (99.8 km/h) Impact Angle . 15.l deg Speed at Para 11e1. . 57. 3 mi/h (92. 2 km/h) Exit Speed . • . . . 57. O mi/h (91. 7 km/h) Exit Trajectory . . 3.5 deg Veh.icle Accelerations

(Max. 0.050-sec Avg) Longitudinal ... -5.3 g Lateral . • . . • -7.3 g

Occupant Impact Velocity Longi tudi na 1 . • • 16. 3 ft/s ( 5. O m/s) Lateral ..... 18.4 ft/s (5.6 m/s)

Occupant Ridedo~n Accelerations Longitudinal ... -3.2 g Lateral ....• -6.2 g ~.~ .. ~T Movement ••••• 6.0 in (15.2 cm)

Figure 37. Summary of results for test 9429K-l.

CONCLUSIONS

A new single-slope CMB has been developed. The new single-slope CMB can be used as a either a temporary or permanent barrier. The new barrier was designed to redirect both heavy and light automobiles with approximately the same response characteristics as the New Jersey CMB. The new single-slope CMB was designed to redirect a 4,500-lb {2043 kg) automobile traveling at 60 mph { 96. 6 km/h) with an imp act angle of 25 degrees with only cosmetic damage when deployed in the permanent configuration. Further, it was designed to redirect a 4,500- lb {2043 kg) automobile traveling at 60 mph (96.6 km/h) with an impact angle of 15 degrees when deployed in either of two different temporary configurations. It is probable that the new single-slope barrier will be able to successfully redirect more severe impacts involving heavier vehicles with higher centers of gravity.

The primary advantage of the new single-slope CMB is that it will not be necessary to reset the barrier each time that the surrounding pavement is overlaid as required with the New Jersey CMB. As stated in the previous section, the center of the wheel hub of the vehicle in the third test rose to a maximu~ height of no more than 30 in {76 cm) before losing contact with the barrier. Experience suggests that the barrier would continue to redirect the vehicle as 1 ong as the contact height of the center of the wheel hub does not exceed the height of the barrier. Therefore, it is anticipated that the overall height of the barrier can be reduced to at least 30 in (76 cm) by adjacent pavement overlays without significantly affecting the performance of the barrier for the test conditions presented in this report. It is possible that the barrier would continue to perform satisfactorily at lower heights; however, it is not recommended that it be used at heights below 30 in {76 cm) unless further tests are conducted.

Another advantage of the new single-slope barrier is that the redirection of the 1,800-lb {817 kg) vehicle appeared to be much more

57

stable than analogous redirections observed with the New Jersey CMB (8). While further study is required to make a definitive statement on this

matter it is believed that the new single-slope CMB will result in fewer roll-over crashes than occur with the New Jersey CMB. This is particularly true with nontracking, high angle, low velocity impacts of small vehicles.

A total of four full-scale tests were conducted on the new single-

s 1 ope CMB. The first test i nvo 1 ved a 4, 500-1 b ( 2043 kg) automobile impacting the new barrier in a temporary configuration. The second and

third tests involved an 1,800-lb (817 kg) automobile and a 4,500-lb

(2043 kg) automobile impacting the single-slope CMB in a permanent

configuration. The fourth test involved a 4,500 lb (2043 kg) automobile

impacting the single-slope CMB in an alternate temporary configuration. In all cases, the vehicles were smoothly redirected with no snagging. Results

from these tests were within acceptable limits for roll, pitch, yaw,

acceleration as described in NCHRP 230 (1). As such the new single-slope

CMS is recommended for immediate use.

58

APPENDIX A.

FABRICATION DETAILS FOR

SINGLE~SLOPE CMB

59

0\ 0

H2 BM

NOTE: M'PRO)(. 1• SPACE: BEl'«EN AOJOIHllG

---------BM-llEll __ · SEC-110NS- }-- li" -i i----------------3tl- o- 1..0.A. I I ...., __________ ,,._ O"--------

, 1 /r Slttl. pp[ l.OC;ATED AT CIUNUElt l'ON~. ro AID IN

UF11NC M BARRIER (7.5 ft. FROM EACH ENO)

17 1/r ,_.~·. . . . I 8 BARS l 7 l(4" # t BAAS

REBAR GRID

PLAN VfEW (~ABOUT CENltR UNES)

. . . I t I -.----·----· I I I I I I -"'----,-----,. t• I I I I I -... -- - ----... I I I I I I _..,. ____ .,. __ _ I I I I I I _.__ -__ ._ _ --_ ... . . '

ELEVATION TYPICAL PROFILE

(SWMETAICAL ABOUT CENlER LINES) i-------------------s-e·---------------~· l.5° 4.5°

5/11" 5/18°

DETAIL 1 DETAIL 2 ·

Y2 llM (I ., • ., GRAOE 40)

YI BAR (I ..... GRADE 40)

REINF"ORCING STEEL DETAILS

H2 8Nt

ASn C-50 1/'Z" Pu.TE

r SECTION

10 112· A572 C-50 I" DIA. ·Ra>

L _[,I/•" I- 3• -I n_j_

I 1irT WIUIAMS C2T 5lOP nPt COUPLING. OR COUfVAl..ENl

DETAIL 3

, t/r STEn ppt l.DCAlED liT OUAIUER

POIN'l'S TO AIO IN UF11NO 1HE BARRIER

(7.S rt.· fllQM EACH ENO)

1 'J/4" (1'1'. CCMll)

SECTION B-B

I. ANClE · SECllONS AND AU. Stm.. PUTES SHAU. CONFORM 10 . AS'IM OE'SIONAllON AJe.

2. BEARING PAO$ SHAU. BE llAOE Of AN o.ASl'CJMElRIC MATERIAi,. WllH A·HARONEss °'so DUltOM£1[R ANO All[ TO BE E:POXlf:D TO EliOf ENO Of BARRIER ~r AflER CliSTINO.

·AU. COIO£l!: SHALL 11£ CUSS A, C. OR H, \K.ESS OTHERWISE SPECIFIED.

4'. ALL RENFORONO STECl. SHALL BE GRAOE to. UNLESS OTHERWISE: SPECIFIED.

5. ~· BARRIER SHAU. BE DEU-.Om Wl1" 2 SPUCE L 5" X 'J" X 1/2" SECTIONS AND CONNECTINO HAllC>WAllL

I. Wff£N. BMRl£1t IS TO 8E Pl.ACED 14 A Q.lltWjC. AWGtlMENT. M AN(LE SEC1IONS llAY BE HEATED AT iHE MiDPOINT. AND PRE-BENT.

7. CHAMFER ENO EOG£S l/~.

a. REINf'ORCtlQ s~ BOLTS, NUTS. WASHDtS, ANGLE SEC'llOMS, ANO ANCHORACE Pl.Aft$ SHALL BE~ SUBSIDIARY TO IHE BID ITEM.

SINGLE SLOPE CONCRETE BARRIER

PORTABLE & PERMANENT PRO.ECT NO.

9&29 - D """"·BY

W.L.B. ORA'lllN BY

J.t..

SCALE HON[

Figure 38. Fabrication details for single-slope CMB

I 13-112·

Welded Wire Fabric 3x12 - 018 x 020

6·0 kst minimum yield strength

_L_ ENO VIEW

I

~

J

I

12·

I

t

'

I

I

l

'

SIDE VIEW

Fi'gure 39. Alternate wire mesh reinforcing scheme for single slope CMB

\

l ~ I I~

' ~ , I

I

I

j . , j , I

I

1 I

I

APPENDIX B.

SEQUENTIAL PHOTOGRAPHS OF CRASH TESTS

62

o.ooo s

0.064 s

0.127 s

0.191 s

Figure 40. Sequential photographs for test 9429C-1.

63

Figure 40.

0.254 s

0.318 s

0.381 s

0.445 s

Sequential photographs for test 9429C-l (continued).

64

0.000 s

0.037 s

0.073 s

0 .110 s

. .... - " -" ~ ~ ~' . .: ""~ -~.

..... ' -.. ~- \ . ". -s-t-fer I •; -M> • .,.

.... .,, ' ., ·. - ; - . . -

. ... ' - . . ; . ' . . '•


65

' .. . :-,,, .. • . ;: I .-

0.146 s

• "f . - ~ . 1 -

o.1a3 s

. . .. ,, . . . .... . ' .

0.248 s

' .*+,~ ~ ~ ·~· . , . .

o. 309 s


66

.... ....... .: ·-·

. . . .. .... .......... ~ ..... h tr ~ ......... "'"' -

0.000 s

\

0.060 s

\ . t

0.120 s

0.180 s

..........

........ .;:. - .

i"~.· ·tiibJ.·'.~ '.;~~~..... ;r.,;.·.• .,,.' -~-/:~\ -~

.• '-!'.

•.'f"'. .. •J.. •· ~. - -· -....... ,...; ... . .p-> . ./'

,...... . ~ ...

:w

Figure 42,

. ..-· ... : ····x··· ....... ·i; .. -..

# l

ij.1'*;1~; .. -.. ,. ~

::.Jt~ ,._';- ~-... r·~"· ..

0.240 s

0.300 s

'

;··Ji . 'R

'

1'·,

,'.".::~-.' .. 1'· ·.' ~ .. ~ '· ~ : ·"' :.

o.~63 s

0.450 s

·.!~ ··"11-~-·· ./

. ..:~~ : ' . .:,..;~ ... -..A'* .........

·. "tt;~\' ~~-llJ!::·· ·~.,;:''·~ ~.-·'-~

Sequential photographs for test 9429C-3. (Continued)

68

0.000 s

,.I: .... ;i:.- ,··!

0.049 s

0.099 s

i I f

• ·11-.-

l

---~.,

Cr

- - ~. :· * ;~}

_-.:::.,. ..

.,--_ , .. · :.-~---·~·1:

_ .. ;!"~........ '

-lJJ ___ .. 0 .148 s

Figure 43. Sequential photographs of test 9429K-1.

69

0.198 s

,;~~;-~:~;·1~ ;::_:'.··:~ 4., -'--=--~Ii.:·'. "'~:.~·.

0.247 s

•fl~ -. ~ .,,;

0.307 s

r~~··· --\ .

't ..

'"\ _J i 1 .

.. ·,. ~~;;."~·.1 .

. ;. "'" ··,:._.

0.371 s

Figure 43. Sequential photographs of test 9429K-1 (continued).

70

APPENDIX C ..

ACCELEROMETER TRACES AND PLOTS OF

ROLL, PITCH, AND YAW RATES

71

• an

• 0 -

• _in (f) UJ UJ ~ (..!)

Wo Cl • -t-z UJ l:: • w"? u cc __. tl.. Cf) • t-tO

01

• U> -I

• 0 N

I

TIME .3

Axes are vehicle fixed. Sequence for determining orientation is:

1. Yaw 2. Pitch 3. Roll

Roll

Yaw

Figure 44. Vehicle angular displacements for test 9429C-1.

72

TEST 9429C-1 300 Hz F1Jter

20 I 1-- - - Max· mum 0.050-second Ave' ·age = -3. 2 g -

15 I

" 1 • a 10 v

I

I z 0

~ 5 bl .J

I I I

I Iii 0 0 ~ ~ z -5 0

. .. _A .ft .. A A ... .. • .. I& ··- -

la A_•- a

~ wvr ' vvvv\ 'VVJ rvv· ••.-~r ·r-·v-

'

' I ::> I-a % -10 g

I I I

I -15

I I I

-20 I

0 0.1 0.2 O.J 0.4 0.5 0.8

TIME (SEcorms)

figure 45. Longitudinal accelerometer trace for test 9429C-l.

73

TEST 9429C-1 300 Hz Fiiter

I I

I~ ~I - Maximu111 0.050-sec ond Averac e == -6.8 g I "' _. I ""' ~ 15 I I I I

I I "

10 • ... 0 ...,

.·· I I I I

I I z 5 0

I I I I

~ ~ 0 bl 0 ~

~ -5

I 1. i~ J I t l .IJIA .. &l.all .. - .. ... -~, I

t~ ~ V' r' ryv• ···1r .- "' v-r· .. • ... ...,

I 1m I

-i-- .. Id

~ -10

I I I I

-15

I I -20 I I

0 0.1 0.2 0.3 0.4 0.5 o.s

TIME {SECONDS)

Figure 46.. Latera 1 acce 1 erometer trace for test 9429C-1 .

74


20 I I I - - I - Maximur i O .050-sec ond , .... ~ ,-

Aver4 ge = -2.4 g I I I l 15

I I " 10 • .. ! z s 0 ~ ~ 0 Id 8 <

I I I I ' I I

l ' I L~ AA. .. _ .. --

1

I 1~· µ \/ '.\IJ\t ~v·v -vy,

g -5 ~ bl > -10

I I

I I I I I I I I I I I I -15 I I

-20 I I 0 0.1 0.2 0.3 0.4 0.5 0.8

TIME (SECONDS)

Figure 47. Vertical accelerometer trace for test 9429C-1.

75

-(/') UJ UJ

• 0

0 •

°' U) • UJ~ Cl I -t-z UJ • J::O UJ~ u a: _J

0... (/) . ...... o or;>

• 0 ... I

Axes are vehicle fixed. Sequence for determining orie,ntation is:


TI ME CSECONDS> Pitch

Yaw


76


m""T9'"T---r--1-----T-----r-----.------;-~--..--------~--

M imum 0 050-sec nd Aver ge ~ -6.5 g

" 10

• 0 ..., z 0

~ 0 Id

Iii 0 ~ ~ z -10 -0 g a z 9 -20

-~;.m----.----... --.-. ... --........ -..i1~ ........ --...-... ---0 0.1 0.2 0.3 0.4 0.5 0.8 0.7 0.8

TIME (SECONDS)

Figure 49. Longitudinal accelerometer trace for test 9429C-2.

77

TEST 9429C-2 300 Hz F1lter

. 050-s.e ond Ave age = - 5. 3 g

~ 0 -0 v z 0

~ ~·

-10

Id

§ -20 i jd

~ -30

-~-,..--~~--.... ----it----.... ----... --------... ----0 0.1 0.2 D.3 0.4 0.5 0.8 0.7 0.8

TIME (SECONDS)

Figure . 50.. Lateral accelerometer trace for test 9429C-2.

78

TEST 9429C-2 JOO Hz Filter

" • -a v z 10 0

~ ~ 0 0 ~ g

-10 ~ bJ >

-20

-~, ............. __ ........................... __ ........ __ ....... __ . 0 0.1 0.2 0.3 0.4 0.5 0.8 0.7 0.8

TIME (SECOODS)

Figure 51. Vertical accelerometer trace for test 9429C-2.

79

-(/) UJ

• 0 ....

• C) N

UJC • ~ (.!)

UJ Cl """' •

0 t-N z• UJ l:: UJ LI a:ci ..J• Q... (/) ....... Cl

I

• 0

'° I

• C> 00

I

Axes are vehicle fixed. Sequence for determining orientation is:


Pitch

Roll

Yaw


80

TEST 9429C-3 300 Hz f1lter

20 J I

15

L '~ Ma; • 0. 050 SE c avg. = - ) • 5 g ,~ ' ! -I I

" • .. 10 a v z 0

I 5 Id .J

~ 0 ·~

~

I I I I

I I I I I I j I

I I I I I J J I~ .. • 11 M ... . -. • &.·a a._& ..

I~ 'Ill

I~ ~ I' II r .-,r 1 !Y Tf• - ..... --, ....... -v •1

I z -s 0 ·.~ 0 z ~10 9

I I J

-15 I I I I

-20 I I

0 0.1 0.2 o.J 0.4 0.5 0.8

TIME (SECONDS)

figure 53. Longitudinal accelerometer trace for test 9429C-3.

81


20------1---,------------------------------w I _ I _ I - I-.. Ma;~. 0.050 sec avg. = - L3.0 g

10-"-----~1 -+-+M--~---+~~--+~-----t-------f~~----t I I

I 'l 1_ IAalu J. __ .al ... -1 ... _.a_ .. ' ,,, ... ,rYVJ•-., ..... ,,, ..... ..

I ~ - - -••9 r .. w ·w .., ....... ,.

~I -20 -'----1---11~~----+----;-----+-----+-----~ I . I I ; I

-~-'--~~!~~i~l----+-~--;~--~-+-----+-----~---4 I I I I

-40 ______ 1 _....! ______________ ..... ____ .... ____ _

0 0.1 0.2 0.3 0.4 0.8

TIME (SECONDS)

Figure 54. lateral accelerometer trace for test 9429C-3

82

" I 0 "

TEST 9429C-3 300 Hz f1lter

M x. 0.050 s c avg~ = .2 g

10 ....,___-H++--Nl------f++-+-l-----+-----+....---+-------1

'1 I

~_.__~~I~-+-+-~~~-+-~~~~

I -~-..----... 1 ____ ... ____________ .... ____ ... ____ _

0 0.1 0.2 0.3 0.4 o.:; 0.8

TIME .(SECONDS)

Figure 55. Vertical accelerometer trace for test 9429C-3

83

-U1

• 0 N

UJ • wo ~-(.!)

UJ Cl -r-o z· UJ L: UJ u a:c:i ..J-CL t en t-t

Cl . 0 N

'

9429K-t

9429K-1

9429K-1

1 ·Z

~. C.H . ·®·· .' .· .. ··.V. AW ·~... _;!---. ~ -

9429K-1 · Closs 180 Filter

30------------------~-------------....-----------------------

Maxim m 0.050 seco d Average = -5.3

20-t-----+----+---------t-----------+------------+----------1

" n ... " v z

10 0

~ hi .J hJ 0 0 ~ .J < z 0 :> -10 I-0 z g

-30-. ....................................................................... ...

0 0.1 0.2 O.J 0.4 0.5

TIME (SECONDS)

Figure 57. Longitudinal accelerometer trace for test 9429K-1.

85

9429K-1 Class ·180 Filter

20 t I I I I ·~ - . - Maximum 0.650-second; Average = -7 .3 g ~ .. ,~

15 I I I I I I

10 I I " ., b 5 v

z 0 0

~ w

I I I. I I

I I I •• A. ~ .A L ·- - I I ~II• ....... llL. -' . ~ r·~ rr II .. 1111r ,.,. llr T. .. I .... I ..I -5 w - ... u ~ -10 J

I I .

~ I w

-15 ~

-20

I

I I I I

I I I

-25 I I I I

I I -JO I I

0 0.1 0.2 O.J 0.4 0.5

llME {SECONDS}

Figure 58. Lateral accelerometer trace for test 9429K-1.

86

9429K-1 Class 180 Filter

30 I I . I I I I - - . Maximum 0.050-seco9d Average = 2.9 g ...... -' I I I I

20 .. . I I I I

" n I h v

10 z 0

~ bJ ..J 0 hJ 0

~

1 . ' I

~ I

• f I L~A n. a1 ~ I _. ,,JtJ\ /\th.

YI

I ~~ . ~ \ ''¥¥\ n a • 1· ..... y I. ,,- vv

I I

~ -10 ~ w >

I I I I I

I I I I

-20 I I I I I I I I

-30 I I

0 0.1 0 .• 2 O.J 0.4 0.5

TIME (SECONDS)

Figure 59. Verti ca 1 acce 1 erometer trace for test 9429K-1.

87

REFERENCES

I. Michie, J.D., "Recommended Practices for- the Safety Performance Evaluation of Highway Appurtenances," NCHRP Report 230, March 1981.

2. Buth

3. Beason, W.L., Hirsch, T .J., and

4. Segal, D.J., "Highway-Vehicle-Object-Simulation-Model-1976," Report Numbers FHWA-RD-75-162 through 165, 4 Volumes, Calspan Corporation, Buffalo, New York, 1976.

5. Perera, H.S, "Simulation of Vehicular Impacts with Safety Shaped Barrier," Ph.D. Dissertation, Department of Civil Engineering, Texas A&M University, College Station, Texas, 1987.

6. Ross, H.E., Perera, H.S.,. Sicking, D.L., and Bligh, R.P., "Roadside Safety Design for Small Vehicles," Final Report, NCHRP Project 22-6, 2 Volumes.

7. Hancock, K.t., Bronstad, M. E., and McDevitt, C. F., "Crash Test Evaluation of Selected Bridge Rails," Preprint of Paper Prepared for Presentation at the 66th Annua 1 Meeting of the Transportation Research Board, January, 1987.

8. Ross, H.E., Michie, J.D., and Sicking, D.L, "Update of Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances," Research Project No. NCHRP 22-7 in Progress at the Texas Transportation Institute, Texas A&M University, 1989.

88

Documents

DEVELOPMENT DF A SINBLE-SLCIPE · 2018. 10. 23. · DEVELOPMENT OF A SINGLE-SLOPE CONCRETE MEDIAN BARRIER by W. Lynn Beason, H.E. Ross, Jr., H.S. Perera, Wanda Campise, and D.L. Bullard,Jr