Hawaii Pacific GIS Conference 2012: Engineering and Public Works - GIS Applications in Geotechnical...

Preview:

DESCRIPTION

 

Citation preview

GIS Applications in Geotechnical (Soils) & Environmental

Engineering

Hawaii Pacific GIS Conference 2012 March 7, 2012

1

Elise Leroux, Associate

2

Geotechnical Consulting

2

3

Slope stability study, near

Hāwī, Big Island

3

4

Dam safety study, Kaua‛i

Geotechnical

investigation, Mauna

Lani, Big Island

4

5

Compaction testing

on new waterline,

Moloka‛i

Mass grading for

housing at Ford

Island, O‛ahu

5

6

Pile driving, Arizona

Memorial Visitor Center,

Pearl Harbor

6

Geotechnical test pit for

Waimānalo Stream restoration

7

What does this have to do with GIS?

Maps for Project Reports

9

Location maps

9

10

Geologic mapping

10

11

Geologic mapping; differing

soils

12

Historic geologic mapping

13

Soil mapping

13

Maps for Field Investigations

15

Mapping sample locations – Step 1: layout points based on plan

16

Mapping sample locations – Step 2: georeference plan

17

Mapping sample locations – Step 3: remove plan

18

Mapping sample locations – Step 4: add coordinates; grid

19 Example on large project

Historical Landforms and Planned Construction

20

Map depicting former sump and boring locations

21

22

Location

23 Georeference historical map

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38 Georeference historical photo

39

40

41

Approximate the boundary based on historical maps & photos

42 Overlay site plan

Map book for road design

43

44

45

46

47

48

49

Hydrology and hydrogeology

49

50

Sheet piling,

Middle Street,

Honolulu

50

Slope stabilization,

Nu‛uanu Stream,

O‛ahu

51

Stormwater Runoff and GIS

51

52

Calculating runoff to plan for

construction

52

53 53

Surface water hydraulic analysis

Problem: stormwater washing out road during construction

Who is responsible for extra costs?

54

Analysis procedure

Map problem areas

Map contributing drainage area(s) for each

Calculate design flow for each drainage area

Calculate design drainage for each problem area

Based on road linear foot

55

56

57

Analysis continued

Calculate flows from actual storm

Compare with design flows (design was greater)

Estimate necessary size of diversion structures

Compare with original design

58

59

60

Environmental Consulting

Environmental

sampling at

Kalaeloa, O‛ahu

60

61

Environmental Investigations

Direct push

drilling for

groundwater

contamination

investigation,

Waikīkī

61

62

Environmental

soil sampling,

Hanua Street,

Kapolei

62

DETERMINING SAMPLE LOCATIONS

63

64

65

66

Mapping sample locations 66

67

68

Environmental Permitting

68

Excavation that

will require

dewatering,

Honolulu Zoo,

Waikīkī

69

Environmental Permitting

69

70

Environmental Permitting

70

71

Environmental Planning

71

ROCKFALLS

72

Boulder problem

73

74

From whose land did it come?

75

76

Step 1: Map possible source based on contours

77

Georeference historical image

Georeferencing is imprecise

Nature of aerial imagery from low-flying aircraft

Distortion away from flightline

Vast changes in landscape & development

Few tie-points

78

79

This one is better due to increased tie-points

80

Multiple historical images may help

81

Landowners

Analysis

Boulder came from state land

Unclear if it was from land previously “worked”

Recommend field investigation

May be possible to determine exact location

Can assess future hazards

82

IMAGES FOR COMMUNITY MEETINGS

83

84

Rock slide investigation,

Koko Crater, O‛ahu

84

85

85

86

Boulder investigation,

Koko Crater, O‛ahu

86

87

Images for community presentations

87

Boulder locations & elevations

Koko Crater Rock Fall Investigation,

April 2009

$

88

Rock slide probable path

88

$

89

90

Rock slide probable path

90

$

91

Rock slide probable path

91

$

92

QUESTIONS?

92

93

Mahalo!

Contact info:

Elise Leroux

eleroux@masafujioka.com

tel. (808) 484-5366

Masa Fujioka & Associates

98-021 Kamehameha Hwy #337

Aiea, HI 06701

93

Recommended