层状土中静压桩连续贯入现场试验与数值模拟  

Field Test and Numerical Simulation of Continuous Penetration of Jacked Pile in Layered Soil

作　　者：吴泽坤 何来胜 白晓宇[1] 麻栋栋 牛永昌 赵广 桑松魁 闫楠[1] 张明义[1] Wu Zekun;He Laisheng;Bai Xiaoyu;Ma Dongdong;Niu Yongchang;Zhao Guang;Sang Songkui;Yan Nan;Zhang Mingyi(School of Civil Engineering,Qingdao University of Technology,Qingdao 266520,Shandong,China;The Fifth Bureau of China State Construction Engineering Corporation,Changsha 410004,China;China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Qingdao Metro Planning and Design Institute Co.,Ltd.,Qingdao 266035,Shandong,China;Beris Engineering and Research Corporation,Qingdao 266555,Shandong,China)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266520 [2]中国建筑第五工程局有限公司,长沙410004 [3]中铁建设集团有限公司,北京100040 [4]青岛市地铁规划设计院有限公司,山东青岛266035 [5]中冶东方工程技术有限公司,山东青岛266555

出　　处：《吉林大学学报（地球科学版）》2024年第4期1291-1304,共14页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(51778312,51708316);山东省自然科学基金重点项目(ZR2020KE009);山东省博士后创新项目(201903043)。

摘　　要：为探讨层状土中静压桩连续贯入过程的沉贯特性,依托上海市某桩基工程开展静压桩贯入过程现场试验,探究沉桩阻力随贯入深度的演变规律,并结合ABAQUS数值模拟,明确静压桩贯入过程中沉桩阻力、桩周土体竖向应力、径向应力以及径向位移的变化规律。结果表明:层状土的软硬程度制约着沉桩阻力的大小;当桩端贯入浅部粉质黏土层和淤泥质黏土层时,沉桩阻力增长较慢甚至出现减小趋势,当桩端贯入到深部砂质粉土层、粉质黏土层和粉砂层时,沉桩阻力增长较快,其中在砂质粉土层中增长率最高可达174%;桩周土体中竖向应力和径向应力与土层性质密切相关,竖向应力和径向应力最大值均出现在桩端贯入至黏质粉土层时,分别为558.0、1 178.0 kPa,当桩端贯入到下部较软的淤泥质黏土层时,最大竖向应力和径向应力均出现明显退化现象,径向应力退化率达到52%;径向位移随径向距离的增加而减小,其变化规律基本反映了土层性质的变化特征。In order to investigate the jacking characteristics of continuous penetration of jacked piles in layered soils,a field test is conducted in a pile foundation project in Shanghai to explore the evolution of jacking resistance with penetration depth.Combined with numerical simulation by software ABAQUS,the variation of vertical stress,radial stress and radial displacement of the soil around the pile during the penetration process of jacked pile is clarified.The results show that the softness and hardness of the layered soil govern the magnitude of the jacking resistance.When the pile body is located in the cohesive soil layer,the pile sinking resistance increases slowly or even decreases,and when the pile body is located in the silty clay and sandy silt soil layer,the pile sinking resistance increases faster,and the growth rate can reach 174%in the sandy silt soil layer.The vertical stress and radial stress in the soil around the pile are closely related to the soil properties.The maximum values of the vertical stress and radial stress appear when the pile end penetrates into the clay soil,which are 558.0 kPa and 1178.0 kPa respectively.When the pile end penetrates into the softer silty clay layer below,the maximum vertical stress and radial stress both deteriorate significantly.The radial stress degradation rate reached 52%.The radial displacement decreases with the increase of radial distance,and its variation regular basically reflects the variation characteristics of soil layer properties.

关 键 词：静压桩 现场试验 沉桩阻力 数值模拟 竖向应力 径向应力 径向位移 

分 类 号：TU473.1[建筑科学—结构工程]