SALSAFLORENCE & HUTCHESON

LEE SEWELL, PE, SE

SIGNAL AND LIGHTING STRUCTURAL ANAYLSIS (SALSA)

ANALYZES WIRE SPAN, MAST ARM AND HIGH MAST STRUCTURES

WHAT IS SALSA?

STARTED IN 2007◦ EXPAND ON EARLIER GEOTECHNICAL

EVALUATIONS DONE BY DARRIN BECKETT IN 2004. AT THE TIME, POLE BASES DIDN’T HAVE

DOCUMENTED DESIGN.◦ 10FT BASE

BRING THE DESIGN UP TO CURRENT CODE.◦ AASHTO STANDARD SPECIFICATIONS FOR

STRUCTURAL SUPPORTS FOR HIGHWAY SIGNS, LUMINAIRES AND TRAFFIC SIGNALS.

HISTORY OF PROJECT

REMOVE THE NEED FOR PERFORMING SITE-SPECIFIC GEOTECHNICAL INVESTIGATIONS.

CHALLENGES◦ ENCOMPASS ALL TYPES OF SOIL THAT COULD BE

ENCOUNTERED◦ CONSERVATISM

HISTORY OF PROJECT

MODELED FOUNDATIONS UNDER VARYING SOIL AND SLOPE CONDITIONS.◦ COHESIVE AND COHESIONLESS SOILS AND ROCK

COHESION = 1 KSF FRICTION ANGLE = 30 DEG

◦ 3:1, 2:1, 1.5:1

HISTORY OF PROJECT

DIAMETER◦ DRIVEN BY ANCHOR BOLT CIRCLE OF POLES

36” MAST ARM AND WIRE SPAN POLES 48” HIGH MAST

EMBEDMENT (AASHTO 13.6.1)◦ BROMS DESIGN METHOD

BASED ON ULTIMATE STRENGTH DESIGN, SO SAFETY FACTORS ARE APPLIED TO SHEARS AND MOMENTS.

DRILLED SHAFT DESIGN

◦ BROMS DESIGN METHOD◦ SAFETY FACTORS (AASHTO RECOMMENDS)

UNDERCAPACITY FACTOR OF SOIL: 0.7 OVERLOAD FACTOR FOR LOADINGS: 3 SAFETY FACTOR = 4.3

◦ THE HIGH SAFETY FACTORS WERE AGREED ON BY THE GEOTECHNICAL DEPARTMENT DUE TO THE UNCERTAINTY OF THE TYPE OF SOIL.

DRILLED SHAFT DESIGN

DESIGN TABLE DEVELOPED

DRILLED SHAFT DESIGN

AASHTO SECTION 3: LOADS◦ OUTLINES LOADING ON POLES AND

ATTACHMENTS SALSA IS USED TO FIND LOADS ON POLE

BASES

POLE BASE LOADS

SALSA

ANALYZES WIRE SPAN, MAST ARM AND HIGH MAST STRUCTURES

MAST ARM AND HIGH MAST LOADS ARE FOUND BY SIMPLE STATICS

SPAN WIRE ANAYLSIS◦ DETAILED METHOD OF ANALYSIS ◦ AASHTO A8

SALSA

MAST ARM AND HIGH MAST◦ LOADING FOR BASE DESIGN

WIRE SPAN◦ LOADING FOR BASE DESIGN◦ LOADING FOR POLE SELECTION FROM STORAGE

YARD

SALSA

WIRE SPAN POLE SELECTION◦ PREVIOUS DESIGN

IN-HOUSE SPREADSHEET FOR WIRE SPAN STRUCTURES NEGLECTED WIND AND ICE LOADS

◦ SALSA CALCULATES MOMENTS COMPARES THEM TO THE

ALLOWABLE MOMENTS FOR POLES IN THE YARD.

SALSA

PROBLEMS◦ EXCEL COMPATIBLITY◦ DELIVERY◦ LIMITATIONS

SALSA

MOVING TO A WEB BASED APPLICATION

FUTURE OF SALSA

WEB BASED ADVANTAGES◦ GREATER ACCESS ◦ FILE SHARING◦ UPDATES ARE SEAMLESS◦ MORE USER FRIENDLY

FUTURE OF SALSA

POSSIBLE ADVANCEMENTS◦ STATEWIDE SOIL PROFILING◦ ADDITIONAL FEATURES

POLE BASE VOLUME CALCULATOR ATTACHMENT HEIGHT PLACEMENT

FUTURE OF SALSA

QUESTIONS???