Tanner Creek Stream Diversion Project - Phase 5

Portland, Oregon

Owner: City of Portland Environmental Services

Client Name: RCI Construction Group

Engagement Scope

The Sutor Group was engaged by Robison Construction, Inc. to prepare its entitlement and impact analysis on two separate differing site conditions RCI encountered while micro-tunneling. Our total impact damage claim including liquidated damages held by the project owner totaled $2,040,040.

Project description

Project is separated into two phases of construction which includes 5,380 lineal feet of 72" combined sewage overflow (CSO) pipe and the open cut of 450 lineal feet of 42" and 48". It also included the open cut of 20 manholes ranging in depth from 10 to 44 feet and an Instrumentation System for settlement monitoring.

Entitlement issues

Subsurface differing site conditions and the resulting project delay.

Type of impacts

RCI sustained additional labor, equipment, material and subcontractor costs as a direct result of encountering the differing site conditions. RCI was required to retrieve the micro-tunnel machine at the location of one of the differing site conditions and lost the seal of the retrieval shaft at the other location which resulted in the flooding of the retrieval cell and the loss of ground elevation of the surrounding area.