STP1331

    Fly-Ash-Based Controlled Low-Strength Material (CLSM) Used for Critical Microtunneling Applications

    Published: Jan 1998


      Format Pages Price  
    PDF Version (312K) 14 $25   ADD TO CART
    Complete Source PDF (6.7M) 14 $65   ADD TO CART


    Abstract

    A controlled low-strength material (CLSM) has been successfully used in two microtunneling applications. This CLSM, developed at the U.S. Army Engineer Waterways Experiment Station (WES), is a mixture of ASTM Class C fly ash, ASTM Type I portland cement, bentonite, and water.

    The CLSM was first used during the microtunneling field trials at WES to stabilize a tunnel excavation while retracting the microtunneling machine through unstable, flooded, running sand. The void left by the retracted tunnel machine was filled with the CLSM to provide continuous support to the excavation and avoid settlement of the ground surface.

    Based on the success of the WES tests, the CLSM was used on a second microtunneling project in Newark, California. The CLSM was used to stabilize the soil surrounding the sheet-piled shaft that would be used to launch a microtunnel boring machine. The use of this fly-ash-based CLSM greatly improved the stability of the soils and safety of the shaft during the launch. The use of the CLSM also provided cost savings in excess of $100,000 on the Newark project.

    Keywords:

    CLSM, fly ash, microtunneling, shaft stabilization, Coal-fired electric generating plants produce large amounts of fly


    Author Information:

    Green, BH
    Geologist, Structures Laboratory, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS

    Staheli, K
    Research Civil Engineer, Geotechnical Laboratory, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS

    Bennett, D
    Chief, Soils Research and Testing Center, Geotechnical Laboratory, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS

    Walley, DM
    Geologist, Structures Laboratory, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS


    Paper ID: STP13069S

    Committee/Subcommittee: D18.05

    DOI: 10.1520/STP13069S


    CrossRef ASTM International is a member of CrossRef.