长期荷载下有侧向约束柔性桩复合地基试验

摘要/Abstract

摘要：

摘要：为探讨长期荷载作用下柔性桩复合地基的工作性状，进行了有无侧向约束条件下夯实水泥土桩复合地基的长期荷载对比试验.在复合地基表面埋设沉降标，量测了桩体和土体沉降值，得到了桩和土的沉降随时间的变化规律；通过在桩间土表面、桩顶、桩端埋设土压力盒和在桩身埋设内贴应变片PVC管量测应力值，获得了桩顶与土顶应力、桩-土应力比、桩身轴力随时间发展的变化规律.试验结果表明：在长期荷载作用下，设置了约束长桩夯实水泥土桩复合地基的工作性状明显优于无约束夯实水泥土桩复合地基的工作性状——大幅度缩短了进入沉降稳定时间（约为64%），减小工后沉降量（约为29%~42%），降低桩土应力比约39%；明显地调整了桩身轴力分布.分析认为：采用柔性桩加固软土路基时，在加固区边缘设置刚性长约束桩，能有效地控制路基的工后沉降，提高路基的承载性能.

关键词: , 长期荷载, 侧向约束, 夯实水泥土桩, 复合地基, 模型试验

Abstract:

Abstract： In order to study the bearing behavior of composite foundation with flexible pile at longterm load, comparative experiments of composite foundation with rammed soilcement pile with or without lateral restraint at longterm load were conducted. Settlement marks were laid on the surface of composite foundation to measure the sedimentation of pile and soil, from which the variation law of the sedimentation of pile and soil with time could be obtained. By laying earth pressure cells on the surface and bottom of the foundation and building PVC tube with stain gauge in pile shaft to measure the stress value, the stress variation of pile top and soil top, the stress ratio of pile soil and pile shaft tress change with time were analyzed. The results of comparative tests show that at longterm load, the performance of composite foundation of rammed soil-cement pile with lateral constraint length piles is obviously better than that without lateral restraint, which can greatly shorten the time step in stable phase (approximately 64%) and reduce the settlement after construction (approximately 29% to 42%), and decrease the pilesoil stress ratio approximately 39%, hence adjust the distribution of axial force of pile shaft significantly. It can be acknowledged that when soft soil is treated with flexible pile, the settlement after construction can be effectively reduced and bearing capacity of subgrade can be improved if rigid long pile is set as lateral restraint.

Key words: long-term load, lateral restraint, rammed soilcement pile, composite foundation, model experiment

中图分类号:

TU 447

吴有平1，张可能1,刘杰2，何杰2. 长期荷载下有侧向约束柔性桩复合地基试验[J]. 上海交通大学学报（自然版）, 2014, 48(11): 1568-1573.

WU Youping1,ZHANG Keneng1,LIU Jie2,HE Jie2. Experimental Study of Bearing Behavior of Composite Foundation with Flexible Pile and Lateral Restraint at Long-term Load[J]. Journal of Shanghai Jiaotong University, 2014, 48(11): 1568-1573.

参考文献

［1］Chai J C，Carter J P．Deformation analysis in soft ground improvement［J］. Geotechnical，Geological and Earthquake Engineering，2011，18: 173234．

［2］Lai Y P，Bergado D T，Lorenzo G A，et al．Fullscale reinforced embankment on deep jet mixing improved ground［J］．Ground Improvement，2006，10(04)：153164．

［3］张磊，魏安．软土处理技术的研究与新进展［J］．铁道勘测与设计，2005(2)：6466．

ZHANG Lei， WEI An． Research and new development of treatment technology of soft soil［J］． Railway Survey and Design，2005(2)：6466．

［4］朱明，范建华．浅谈软土地基处理方法及施工工艺［J］．西部探矿工程，2009(1)：2628．

ZHU Ming，FAN Jianhua．Method and construction technology of soft foundation treatment［J］．WestChina Exploration Engineering，2009(1)：2628．

［5］龚晓南．地基处理［M］．北京：中国建筑工业出版社，2005: 148156．

［6］刘海涛，谢新宇，程功，等．刚柔性桩复合地基试验研究［J］．岩土力学, 2005，26(2)： 303306．

LIU Haitao， XIE Xinyu， CHENG Gong，et al． Experimental study of the rigidflexible pile composite foundation［J］． Rock and Soil Mechanics，2005，26(2)：303306．

［7］朱奎，魏纲，徐日庆．刚柔性桩复合地基中桩荷载传递规律试验研究［J］．岩土力学, 2009，30(1)： 201205．

ZHU Kui， WEI Gang， XU Riqing． Research on insitu tests of pile load transfer behaviors in composite foundation with rigid flexible piles［J］． Rock and Soil Mechanics，2009，30(1)：201205.

［8］马骥，张东刚，张震，等．长短桩复合地基设计计算［J］．岩土工程技术, 2001(2)： 8691．

MA Ji，ZHANG Donggang，Zhang Zhen，et al． Design of the composite foundation with longshortpile［J］． Geotechnical Engineering Technique，2001(2)：8691．

［9］李斌．桩体长短与刚度对长短桩复合地基性状影响的模型试验研究［D］．太原：太原理工大学， 2010．

［10］左珅，刘维正，张瑞坤，等．路堤荷载下刚柔长短桩复合地基承载特性研究［J］．西南交通大学学报, 2014(3)：379385．

ZUO Shen， LIU Weizheng，ZHANG Ruikun，et al． Bearing behavior of composite foundation with rigidflexible and longshort piles under embankment load［J］．Journal of Southwest Jiaotong University, 2014(3)： 379385．

［11］Tavenas F， Leroueil S． The behavior of embankment on clay foundation［J］． Canadian Geotechnique， 1980(17)： 236260．

［12］Leroueil S， Magnan J P，Tavenas F． Embankment on soft clays［M］． London： Ellis Horwood Limited，1990: 157170．

［13］Loganathan N，Balasubramaniam A S，Bergado D T．Deformation analysis of embankments［J］．Journal Geotechnical Engineering，1993，119(8): 11851206．

［14］王峰，金武，王宏坤，等．考虑侧向变形影响的客运专线路基沉降的修正［J］．岩土工程学报，2010，32(S2)：245248．

WANG Feng， JIN Wu， WANG Hongkun，et al．Amendment of subgrade settlement of passenger dedicated line considering the lateral deformation effects［J］．Chinese Journal of Geotechnical Engineering，2010，32(S2)：245248．

［15］韩君良，赵岩．高路堤侧向位移沉降特性分析［J］．武汉理工大学学报: 交通科学与工程版, 2012(1)： 165167．

HAN Junliang， ZHAO Yan．Analysis on the settlement characteristic of lateral displacement of the high embankment［J］．Journal of Wuhan University of Technology: Transportation Science & Engineering， 2012(1)： 165167．

［16］丁光文，唐艳．粉喷桩侧向约束在软土地基加固中的运用［J］．路基工程，1999(1)：4950．

DING Guangwen，TANG Yan．Application of powder jet pile for lateral restraint at soft soil foundation treatment［J］．Subgrade Engineering，1999(1)：4950．

［17］吴保全．粉土中格栅结构复合地基的原理与技术方法研究［D］．成都: 成都理工大学，2008．

［18］张军，郑俊杰，马强，等．桩承式加筋路堤挂网技术侧向位移影响分析［J］．华中科技大学学报: 自然科学版，2012，40(1)：6366．

ZHANG Jun， ZHENG Junjie，MA Qiang，et al．Analysis of lateral displacement in fixed geosynthetic technique of geosynthetic reinforced and pile supported embankment［J］．Journal Huazhong University of Science & Technology: Natural Science Edition， 2012，40(1)： 6366．

［19］柏松平，陈兴培，李勇林．侧向限制法软土处理技术研究［J］．公路，2005（7）：127130．

BAI Songping，CHEN Xinpei，LI Yonglin．Study of soft soil treatment technology of lateral restraint［J］．Highway，2005（7）：127130．

［20］吴有平．有无侧向约束夯实水泥土桩复合地基性状对比研究［D］．株洲: 湖南工业大学，2012．

[1]	刘谨豪, 严远忠, 张琪, 卞荣, 贺雷, 叶冠林. 地面堆载对既有隧道影响离心试验和数值分析[J]. 上海交通大学学报, 2022, 56(7): 886-896.
[2]	王聚团, 戚晓宁, 黄志明. 水下生产管汇测试技术及其改进研究[J]. 海洋工程装备与技术, 2022, 9(2): 43-49.
[3]	袁振钦, 邹科, 孙亚峰, 刘刚, 屈衍, 李居跃. 基于时域分析法的动态电缆疲劳分析[J]. 海洋工程装备与技术, 2022, 9(2): 50-55.
[4]	王娟, 杨明旺, 郑茂尧, 刘凌云, 赵立君. 高强钢在大型半潜式平台组块建造中的应用[J]. 海洋工程装备与技术, 2022, 9(1): 27-31.
[5]	陈欣, 赵晓磊, 王立坤, 肖德明, 张腾月. 深水大型吸力锚建造技术研究[J]. 海洋工程装备与技术, 2022, 9(1): 32-36.
[6]	尹彦坤, 易涤非. 半潜式生产平台船体结构关键节点工程临界评估[J]. 海洋工程装备与技术, 2022, 9(1): 52-57.
[7]	陈培帅, 潘亚洲, 梁发云, 李德杰. 沉井接高过程中砂桩复合地基固结承载特性[J]. 上海交通大学学报, 2021, 55(6): 707-715.
[8]	张晨雅, 寇雨丰, 吕海宁, 肖龙飞, 刘明月. 经典式Spar平台涡激运动与驰振特性的对比试验[J]. 上海交通大学学报, 2021, 55(5): 497-504.
[9]	ZHANG Shengfa (张胜发), TANG Na (唐纳), SHEN Guofeng (沈国峰), WANG Han (王悍), QIAO Shan (乔杉). Universal Software Architecture of Magnetic Resonance-Guided Focused Ultrasound Surgery System and Experimental Study[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(4): 471-481.
[10]	MA Qunsheng (马群圣), CEN Xingxing (岑星星), YUAN Junyi (袁骏毅), HOU Xumin (侯旭敏). Word Embedding Bootstrapped Deep Active Learning Method to Information Extraction on Chinese Electronic Medical Record[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(4): 494-502.
[11]	安庆升, 孙立东, 武秋生. 碳纤维增强复合材料发射筒设计研究[J]. 空天防御, 2021, 4(2): 13-.
[12]	KONG Xiangqiang (孔祥强), MENG Xiangxi (孟祥熙), LI Jianbo (李见波), SHANG Yanping (尚燕平), CUI Fulin (崔福林) . Comparative Study on Two-Stage Absorption Refrigeration Systems with Different Working Pairs[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(2): 155-162.
[13]	ZHUANG Weimin (庄蔚敏), WANG Pengyue (王鹏跃), AO Wenhong (熬文宏), CHEN Gang (陈刚) . Experiment and Simulation of Impact Response of Woven CFRP Laminates with Different Stacking Angles[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(2): 218-230.
[14]	ZHOU Xuhui (周旭辉), ZHANG Wenguang (张文光), XIE Jie (谢颉). Effects of Micro-Milling and Laser Engraving on Processing Quality and Implantation Mechanics of PEG-Dexamethasone Coated Neural Probe[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(1): 1-9.
[15]	HUANG Ningning (黄宁宁), MA Yixin (马艺馨), ZHANG Mingzhu (张明珠), GE Hao (葛浩), WU Huawei (吴华伟). Finite Element Modeling of Human Thorax Based on MRI Images for EIT Image Reconstruction[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(1): 33-39.