楔形劲芯水泥土复合桩沉芯效应模型试验研究  

Model Study of Cement Mixed Soil Column with Tapered Rigid Inclusions

作　　者：何杰[1] 熊猛 高建喜 王忍 HE Jie;XIONG Meng;GAO Jianxi;WANG Ren(School of Civil Engineering, Hunan University of Technology, Zhuzhou Hunan 412008)

机构地区：[1]湖南工业大学

出　　处：《土工基础》2018年第2期210-213,共4页Soil Engineering and Foundation

基　　金：湖南省自然科学基金资助项目(16JJ5007)

摘　　要：为探讨楔形劲芯水泥土复合桩在静力沉芯过程中的沉芯效应,在PVC管中分层填筑水泥土,然后分别静力压入1根等截面模型桩和2根不同楔角的楔形模型桩。通过试验数据整理分析,获得等截面和楔形芯桩静力沉芯过程中桩身应变、桩周水泥土表面的竖向位移、贯入阻力与沉芯深度的规律。研究结果表明：在楔形内芯的作用下,楔形劲芯水泥土复合桩不仅内芯对水泥土的挤压作用远大于等截面劲芯水泥土复合桩,而且水泥土外桩也会变成上端大、下端小的楔形形状;沉芯过程中,距楔形芯桩中心10cm监测范围内桩周土表没有出现隆起,而最小沉降量出现在距桩中心10cm处,最小沉降量为1mm;楔形芯桩的贯入阻力随贯入深度和楔角的增加而增加。A model study was performed on the effect of tapered rigid inclusion in the cement mixed columns as a composite ground in the soil improvement applications.A model cement mixed soil column was prepared in a PVC pipe by layers.One instrumented cylindrical aluminum rod and two instrumented tapered aluminum rods with different taper angles were statically pressed in with a hydraulic jack.The strain in the rigid inclusions,vertical displacement of soils surrounding the rods and the rod axial resistance were measured.The results indicate that,under the lateral compression action of the soil in the penetration of the tapered rods,the surrounding soils formed the tapered shape accordingly.During the tapered rod penetration,no soil heaving within the monitoring radius of 10 centimeters.The observed minimum settlement of 1 millimeter had a distance of 10 centimeters to the center of the rigid inclusion.The penetration of the tapered rod increased with the penetration depth.

关 键 词：楔形 静力沉桩 桩身应变 竖向位移 

分 类 号：TU433[建筑科学—岩土工程]