层状土中静压桩贯入过程沉桩阻力现场试验与数值模拟  

Field Test and Numerical Simulation of Resistance during Pile Driving in Layered Soil of Static Pressure Piles

作　　者：桑松魁 孔亮[1,2] 白晓宇[2,3] 王永洪[2,3] 张明义[2,3] SANG Songkui;KONG Liang;BAI Xiaoyu;WANG Yonghong;ZHANG Mingyi(School of Science,Qingdao University of Technology,Qingdao266520,China;School of Civil Engineering,Qingdao University of Technology,Qingdao266520,China;Collaborative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone,Qingdao 266520,China)

机构地区：[1]青岛理工大学理学院,山东青岛266520 [2]青岛理工大学土木工程学院,山东青岛266520 [3]青岛理工大学山东省高等学校蓝色经济区工程建设与安全协同创新中心,山东青岛266520

出　　处：《宁夏工程技术》2022年第3期212-218,225,共8页Ningxia Engineering Technology

基　　金：国家自然科学基金资助项目(12172187,51778311);山东省自然科学基金资助项目(ZR2020KE009)。

摘　　要：为研究层状土中静压桩沉桩阻力的变化特性,依托山东某桩基工程开展了现场静压桩沉桩试验。结合PFC离散元数值模拟软件,建立了层状土中静压桩沉桩的离散元模型,分析了粉土和粉质黏土中静压桩沉桩阻力和桩端阻力的变化规律,并探讨了不同桩径对沉桩阻力和桩端阻力的影响,明确了层状土中沉桩阻力和桩端阻力随贯入深度的分布特性。试验结果表明:土层的软硬程度制约着沉桩阻力的大小,桩端土层越硬、沉桩阻力越大;桩端阻力的变化规律与土层的性质和分布密切相关,且桩端阻力是沉桩阻力的主要组成部分;随着桩径的增大,沉桩阻力和桩端阻力也在增大且两者呈线性增长的趋势愈加明显;随着桩径的增大,桩端底部附带的上部土颗粒增多,且桩端底部附带的上部土颗粒在一定程度上能够改变桩端位置处土体的力学性质。In order to study the variation of resistance during pile driving in layered soil of static pressure piles, a field test was carried out based on a pile foundation project in Shandong province. Combined with PFC discrete element numerical simulation software, the discrete element model of pile driving of the static pressure pile in layered soil was established to analyze the variation laws of pile resistance and pile end resistance in silty soil and silty clay. The influence of different pile diameters on pile resistance and pile end resistance were also discussed. The distribution characteristics of pile resistance and pile end resistance in layered soil with penetration depth were clarified. The test results show that the hardness of soil layer affects the resistance, and the harder the soil layer at pile end, the greater the resistance. The variation of pile end resistance is closely related to the property and distribution of soil layers, and the pile end resistance accounts for the most of the pile resistance.With the increase of pile diameter, the pile resistance and pile end resistance both grow larger, whose linear-growth trend becomes more obvious. With the increase of pile diameter, the upper soil particles attached to the bottom of pile end increase, which can change the mechanical properties of the soil at the position of pile end to a certain extent.

关 键 词：静压桩 沉桩阻力 桩端阻力 离散元 数值模拟 

分 类 号：TU473.1[建筑科学—结构工程]