STP670: Cyclic Pile Load Testing—Loading System and Instrumentation

    Lu, TD
    Senior engineer, senior engineer, and partner, Dames and Moore, Cranford, N.J.

    Miller, VG
    Senior engineer, senior engineer, and partner, Dames and Moore, Cranford, N.J.

    Fischer, JA
    Senior engineer, senior engineer, and partner, Dames and Moore, Cranford, N.J.

    Pages: 16    Published: Jan 1979


    Abstract

    The scope, concepts, methodology, and details of a load application system and instrumentation for the successful operation of a series of cyclic pile load tests are described.

    The purposes of the pile tests on an instrumented H-pile were to evaluate the dynamic behavior of piles under cyclic loading conditions for seismic analyses and design of a structure supported on piles. The scope of the pile load tests included a static vertical, cyclic vertical, and cyclic lateral loading, with a sustained constant vertical load.

    A major requirement of the cycle testing was to apply a controlled varying load intensity to the pile in a specific wave shape at a specific frequency. To fulfill this requirement, an automated closed loop loading system, which consisted of an electronic-electromechanical control system interfaced with hydraulic loading components, was developed.

    An instrumentation program was implemented to measure the static and cyclic response of the test pile to include (a) bending moments and axial compression of the pile during driving; (b) loads, moments, angular rotation, and deflections of the pile during testing; and (c) the configuration of pile after driving and after each increment of load application.

    Keywords:

    pile load testing, instrumental H-pile, instrumentation, cyclic load testing, static and cyclic vertical and lateral load testing, earthquake simulation, load transfer, servo-controlled close loop testing, bonded strain gages


    Paper ID: STP33743S

    Committee/Subcommittee: D18.10

    DOI: 10.1520/STP33743S


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