劲性搅拌桩复合地基承载特性数值分析  

Numerical analysis on bearing behaviors of composite foundation with stiffened deep cement mixing piles

作　　者：朱庆华 朱志慧[1] 左威龙 费康[1] ZHU Qinghua;ZHU Zhihui;ZUO Weilong;FEI Kang(College of Civil Science and Engineering,Yangzhou University,Yangzhou 225000,Jiangsu,China;Jiangsu Surveying and Design Institute of Water Resources Co.,Ltd.,Yangzhou 225000,Jiangsu,China)

机构地区：[1]扬州大学建筑科学与工程学院,江苏扬州225000 [2]江苏省水利勘测设计研究院有限公司,江苏扬州225000

出　　处：《河南理工大学学报（自然科学版）》2022年第1期181-188,共8页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(51778557);江苏省水利科技资助项目(2017017)。

摘　　要：为研究劲性搅拌桩复合地基的承载特性,采用三维弹塑性有限元对其在竖向荷载作用下的响应规律进行分析,并与同等条件下的水泥土搅拌桩复合地基进行对比,重点分析荷载-沉降曲线、桩土应力比、桩身水泥土和混凝土应力发挥过程、桩身应力分布等内容。计算结果表明,劲性搅拌桩复合地基的承载能力优于水泥土搅拌桩复合地基,桩端土层越硬,承载力提高越明显。劲性搅拌桩复合地基的桩土应力比随着垫层厚度的增加而减小,但垫层超过30 cm后桩土应力比变化不大。由于水泥土的竖向变形沿径向非均匀分布,桩顶水泥土-混凝土界面附近的水泥土有受拉破坏的可能。A series of three dimensional elastic-plastic finite element analyses were performed to investigate the bearing bebaviors of composite foundation with stiffened deep cement mixing(SDCM)piles.The relationship between the vertical load and the settlement, the pile-soil stress ratio, the development of stresses in the cement and the concrete of the SDCM pile, and the distribution of the stress were discussed in detail.The computed results were also compared with those of the composite foundation with deep cement mixing(DCM)piles.It was found that the bearing capacity of the composite foundation with SDCM piles was higher than that of the composite foundation with DCM piles, especially for the case in which the pile was supported by a stiff soil.The pile-soil stress ratio was found to decrease with the increase in the thickness of the cushion layer.This effect was negligible when the thickness was larger than 30 cm.Due to the differential settlement along the radial direction, the cement near the concrete-cement interface might fail in tension.

关 键 词：劲性搅拌桩 复合地基 有限元法 承载力 桩土应力比 

分 类 号：TU470.3[建筑科学—结构工程]