基于能量的振冲碎石桩加密效果评价方法  

Energy-based evaluation method for soil densification effects induced by vibro-compaction of stone columns

作　　者：周燕国[1] 王春[1] 庄端阳 姚鹏飞 张东超 ZHOU Yanguo;WANG Chun;ZHUANG Duanyang;YAO Pengfei;ZHANG Dongchao(MOE Key Laboratory of Soft Soil and Geoenvironmental Engineering,Institute of Geotechnical Engineering,Center for Hypergravity Experiment and Interdisciplinary Research,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江大学岩土工程研究所,浙江大学超重力研究中心,浙江杭州310058

出　　处：《岩土工程学报》2024年第S02期16-20,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金基础科学中心项目(51988101);国家自然科学基金面上项目(52278374);岩土工程长期服役性能及调控学科创新引智基地项目(B18047)。

摘　　要：采用常规检测手段进行处理地基的工后质检存在时间滞后与空间局部的问题,不能及时反映处理地基的整体加固效果。提出了一种基于能量的碎石桩复合地基桩周土振动加密效果评价方法,为实现桩周土加密效果的准实时评价提供参考。首先,根据地基弹性波传播理论建立振冲施工过程中桩周土吸收波动能量的计算方法,通过不排水动三轴试验建立典型饱和粉砂土基于吸收能量的超静孔压模型,为进一步根据固结理论预测处理后复合地基桩周土密实度提供依据;其次,依托某工程水电站深厚坝基碎石桩处理工程实例,采用桩周土超静孔压峰值和处理后孔隙比两个关键物理量对方法进行了检验,发现与施工现场实测超静孔压和工后质检得到的孔隙比相比,方法的预测精度达到90%左右,说明基于能量的振冲碎石桩加密效果评价方法具有可行性。In view of the fact that the conventional ground inspection methods are not suitable for the real-time monitoring and quality check of ground improvements due to the limitations in timely and full-scale inspection,an energy-based evaluation method for soil densification effects induced by vibro-compaction of stone columns is proposed,which can timely estimate the average densification effects of soils between stone columns.Based on the propagation theory of elastic waves in foundation,a calculation procedure of energy absorbed by soils is established,and the corresponding undrained cyclic triaxial tests on a prototype silty sand are conducted to establish the empirical model for generation of the excess pore water pressure.Then a case study of a reservoir dam project is conducted.It is found that,compared with that of the field monitored excess pore water pressure and the final void ratio obtained via post-construction inspection,the prediction accuracy of the proposed method is about 90%,which preliminarily validate the feasibility of the proposed method.

关 键 词：振冲碎石桩 振动能量 弹性波 留振加密 超静孔压 

分 类 号：TU432[建筑科学—岩土工程]