2007/11/21 Council Agenda Packet

1t steel pipe. The jog section is underlain by 20 to 25 feet of "pre -consolidated peat' that overlies loose sand of unknown depth. The jog section of the pipeline is supported as follows: • Northwest end - Two rows of shafts. each shaft has one reinforced concrete cap on three 18 -inch diameter and A -foot -lone cylinder steel driven pipes. The pipeline to the north of the joy_ is ,uppoi-ted cm the same type of pile system as at the north end of the job_. • Southeast end - Ballast andgravel till replacement of the peat. The pipeline to the south of the jo�LI is not supported, but is also not underlain by peat. • Middle section — Most likely peat. but this is not clear because a note at the bottom of the profile on drawing Sheet 5 of S states "Remove all pea[ tree coil Bell clepllr ha/o+ pipe and Derck/ill rrith crushed sur/ucing base course evcoht Jot- pipe sul,pnr[ed area". It is understood that the ground surface over the jog section has settled over the years and is occasionally raised back to grade with fill. It is unknown how much differential movement the pipeline jog section and its casing have been subjected to, and what stresses may have been developed at the hinge point between the pile -supported and cased sections of the pipeline. A 1990 Shannon & Wilson geotechnical report describes two nearby borings with ground water at depths of about I foot, but the underlying soils are moist, which suggests a perched water condition. A 2007 HWA GeoSciences geotechnical report describes two borings with ground water at depths of 2.5 and. 5 feet. The ground surfaces of the 2007 borings are higher than the 1990 borings which suggests that ground water under the pipeline jog may be about I foot deep. It is evident that a geotecimical investigation is needed to clarify the existing subsurface soil and Ori�und water conditions, lite structural conditions of the pipeline jog section and casing, and the location of the fiber optic cable and any other utilities that could be nearby. A pipeline support system will be designed based on the results of this investigation. SCOPE ON WORK The design of the pipeline Support will comply with rail design Guidelines, AREMA Manual for Railway Engincenng, and all applicable federal and state design codes. URS will perform the following tasks to protect the 110 -foot -long pipeline jog section: • -Cask 60100: Geotechnical lnvesti,zation • Task 60200: Engineerin; and Design • Task 60300: Plans and Specifications • T -ask 60400: Review Meetings • Task 60500: Construction Services • Task 60600: Undefined Services For the design, URS will maintain staffing continuity from the Phase I and 2 projects: • Cecil Urlich, P.L. Project manager and engineer of record • Brian Hamilton -- .Assistant project mana;er and development of design concepts • Robert Wallace. P.E. — .Lead geotechnical and structural design engineer • Xiangdong [-[an, Ph.D.. P.E. and Martv McCabe, Ph.D., P.[ .�- Geoteclulical engineering • Enam Kazi, P. [ng. and Vichai Vitsupakorl, P.E. — Structural engineering • Ross Atkinson, P.E., S.L., - Structural and colnstrlctability review • Richard Smith. CA .T. -- Cost estimating U RS - 97 Page ? of 10