精密仪器试桩的原理及应用
Principle and application of instrumented pile test
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摘要: 精密仪器试桩借助于钢筋应变计等精密原件可测出各土层在各级荷载下的平均侧摩阻力及桩端阻力,为桩基优化设计提供现实可靠的设计参数,同时可为桩土荷载传递机理的研究、设计计算方法的改进乃至规范局部修订积累宝贵的实践资料。但因缺乏对此类试桩方法系统而权威的介绍,试桩过程无章可寻、无法可依,直接影响了试桩的准确性与实际效果,集中表现在成活率低与数据异常。而实际上,精密仪器试桩是一个完整的系统工程, 从试桩设计与试桩方案、试桩施工与元件的安装到数据的采集与评估等各阶段都需要由有经验的专业人士来完成,才能保证试桩目标的实现。Abstract: The instrumented piles test are possible to establish the unit skin friction and unit end bearing resistance of every soil layer at each load increment by means of the instrumentation parts such as the vibrating wire strain gauge so as to provide reliable parameters for pile design. The test results are also the precious research materials for the load transfer mechanism, design methods and code revision. However the testing accuracy and effect are not satisfied without the systematic and authority introduction, especially the low survival percentage and abnormal data. In fact, the instrumented pile tests are a systematic project, so instrumentation and taking the readings must be planned, executed, and evaluated by persons who have experience in all the phases.