Richmond/San Rafael Bridge HIGH CAPACITY MICROPILE CONSTRUCTION AGRA Foundations, Inc.

Completed in 1956, the 5.5 mile long bridge sits between two fault lines in the San Francisco Bay. The bridge connects the cities of Richmond and San Rafael as part of Interstate 580. Richmond/San Rafael Bridge Photograph courtesy of California Department Transportation

Site Location Richmond/San Rafael Bridge San Francisco HAYWARD FAULT SAN ANDREAS FAULT

Project Hierarchy Date bid: August 08, 1999 Owner: California Department of Transportation General Contractor: A Joint Venture of Tutor Saliba/Koch/Tidewater Prime Subcontractor: AGRA Foundations, Inc.

AGRA’s Scope of Work `` 66” Dia. CIDH Piles 150” Dia. CIDH Piles Substructure Micropiles Superstructure Micropiles

Substructure Micropiles Pile Data Micropiles This table represents 31 pier locations with 476 production piles and 5 performance piles. Load range from 290 kips to 1140 kips

Substructure Micropile Note Spirals at base of pile and rings at Micropile top (inside the bell) Typical CRIP

Prerequisites to Micropiles Work Platforms

Micropile Installation Templates Hinge Locations Templates were constructed to accurately locate the micropiles

Micropile Installation Templates Completed Templates and Conductor Casing Templates in place on Bridge Template Connector

Micropile Installation Conductor Casing Rubber Seat Bell Coring Grooving Pipe placed from bottom of bell and socketted into bedrock (not shown) Foundation Bell Steel Bell Casing Pipe Reinforcement 14” Dia. Cored Hole with Groves Seal Bed Rock Bedrock Socket Mud line Permanent Steel Casing 12” Dia.

Geological Description The Franciscan Formation is a heterogeneous unit of sedimentary and volcanic rock deposited in an offshore, deep-marine trough at the base of the continental slope. The formation consists of massive graywacke sandstone, dark shale, minor chert and limestone, altered volcanic rock, and various metamorphic rocks. All of the rock is intruded by serpentine. The Franciscan Formation is believed to be as thick as 50,000 feet and typically found as fault-bound blocks accreted onto the western shoreline of California by plate movement.

Bed Rock Topographic Contours

Log of Test Bore Working Drawing Load Capacity Calculations

Micropile Testing

Load Test Result Summary

Construction Methods

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