高应变动力测试CASE法分析嵌岩桩的承载特性

Analysis of bearing capacity of rock socketed pile by CASE high strain dynamic testing method

嵌岩桩的承载特性随桩周岩层的地质情况、施工工艺、桩底沉渣及嵌岩深度等情况的不同变化很大。由于"一维杆件假定"的条件限制以及桩端反射不确定等原因,导致反射波法在大直径嵌岩桩检测的应用上有一定争议,认为高应变法不适用于嵌岩桩的承载力检测。本文通过对大量的嵌岩桩高应变检测数据研究分析,说明在充分考虑嵌岩桩工作机理的前提下,应用高应变法检测嵌岩桩的承载力是可行的、也是可靠的,试验所测得的桩身承载力是比较准确的,完全可以满足工程设计和施工要求。并且可以通过高应变动力测试CASE法分析确定嵌岩桩的嵌岩效果和桩底岩土性状。

The bearing capacity of rock socketed pile varies greatly with the geological conditions, construction technique, bottom sediment, rock socket depth and so on. As a result of the limit of the ＂one dimension member assumption＂ and the uncertainty of the pile end reflection, the application of the reflection wave method to detect large diameter rock socketed piles is controversial that high strain dynamic testing is not applicable to determine the bearing capacity of rock socketed pile. Based on the analysis of a large number of high strain detection data of rock socketed pile, considering the working mechanism, high strain dynamic testing method to detect the bearing capacity of rock socketed pile is feasible and reliable, and the bearing capacity is accurate. The method could fully meet the requirements of design and construction. It can also be used to determine the socket effect and the founding rock property.