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《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]

卷:

39卷

期数:

2022年01期

页码:

106-115

栏目:

基础工程

出版日期:

2022-02-15

文章信息/Info

Title:

Investigation of Influences of Geosynthetic Reinforcement on Composite Foundation Cushion Under Rigid Slab

文章编号:

1673-2049(2022)01-0106-10

作者:

芮 瑞¹,谷金林¹,郑筱彦²,陈 成¹,翟玉新^1,2,孙 义¹

(1. 武汉理工大学 土木工程与建筑学院,湖北 武汉 430070; 2. 中铁建设集团有限公司,北京 100040)

Author(s):

RUI Rui¹, GU Jin-lin¹, ZHENG Xiao-yan², CHEN Cheng¹, ZHAI Yu-xin^1,2, SUN Yi¹

(1. School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, Hubei, China; 2. China Railway Construction Group Co., Ltd., Beijing 100040, China)

关键词:

复合地基;  褥垫层;  土工加筋;  刚性基础;  活动门试验;  离散元

Keywords:

composite foundation;  cushion;  geosynthetic-reinforcement;  rigid slab;  trapdoor test;  discrete element

分类号:

TU472

DOI:

10.19815/j.jace.2020.12036

文献标志码:

A

摘要:

为了提高桩土荷载分担比,一些建筑工程桩筏基础下的复合地基采用了加筋垫层,然而加筋垫层复合地基的变形协调与荷载传递的影响还缺乏深入研究。采用自制的二维多活动门试验装置与椭圆钢棒相似土填料,开展了无筋褥垫层随桩间土下沉过程的模型试验,获得了不同垫层厚度下无筋垫层的变形与应力协调特性。在模型试验基础上,采用颗粒离散元DEM数值模拟建立了无筋与加筋垫层数值模型,揭示了有、无加筋条件下的褥垫层工作特性区别,并探讨了褥垫层厚度、桩间净距以及加筋位置等对褥垫层工作特性的影响。结果表明:当加筋高度距桩顶超过100 mm时,桩土应力比曲线和褥垫层变形均接近未加筋的情况; 加筋体设置高度小于100 mm时,下方颗粒垫层的变形协调会受到影响,格栅与下部垫层之间产生脱空现象,从而导致桩土应力比随着桩间土下沉量的增加而出现陡升; 陡升段起点对应的桩间土下沉量随着加筋位置的提高而增加,工程中可能会导致复合地基桩体超过承载力而引起复合地基发生破坏。

Abstract:

To improve the pile-soil load transfer efficiency of composite foundation under rigid slab, geosynthetic-reinforced cushion is used under the pile raft foundation in some construction projects. However, the influences of geosynthetic reinforcement on the long-term deformation coordination and load transfer of composite foundation is still lack of in-depth studies. A series of model tests were carried out using a two-dimensional multi-trapdoor test device and elliptical steel rod analytical soil to study the working mechanism of unreinforced cushion of composite foundation. Deformation and stress coordination characteristics under different cushion thicknesses were revealed. Based on the model tests, particle flow discrete element method(DEM)was used to establish the numerical models of reinforced cushion and unreinforced cushion. The differences of working mechanism between reinforced cushion and unreinforced cushion was compared, and the influences of cushion thickness, clear distance between piles and geo-reinforcement height on the cushion working mechanism were discussed. The results show that the pile-soil stress ratios and the deformation are close to the unreinforced cushion when the reinforcement placement height is higher than 100 mm. The deformation coordination of the granular cushion will be affected when the reinforcement height is less than 100 mm, resulting in a rapid increase of pile-soil stress ratio with the increase of subsoil settlement. The starting point of steep rise section of the pile-soil stress ratio curve increase with the increase of reinforcement placement height, which could cause ground failure of piles of the composite foundation.

参考文献/References:

[1] 金宗川,顾源兴,汪 稔,等.垫层作用下石灰桩复合地基工作性状[J].岩土工程学报,1998,20(2):37-40.
JIN Zong-chuan,GU Yuan-xing,WANG Ren,et al.The Behavior of Lime Column Composite Foundation with the Action of Cushion[J].Chinese Journal of Geotechnical Engineering,1998,20(2):37-40.
[2]郑 刚,姜忻良,顾晓鲁.水泥搅拌桩荷载传递机理研究[J].土木工程学报,2002,35(5):82-86.
ZHENG Gang,JIANG Xin-liang,GU Xiao-lu.Research on the Mechanism of Load Transfer for Cement-soil Pile[J].China Civil Engineering Journal,2002,35(5):82-86.
[3]闫明礼,张东刚.CFG桩复合地基技术及工程实践[M].2版.北京:中国水利水电出版社,2006.
YAN Ming-li,ZHANG Dong-gang.CFG Pile Composite Foundation Technique and Practice[M].2nd ed.Beijing:China Water and Power Press,2006.
[4]刘汉龙,谭慧明.加筋褥垫层在PCC桩复合地基中的影响研究[J].岩土工程学报,2008,30(9):1270-1275.
LIU Han-long,TAN Hui-ming.Influence of Reinforced Cushion in PCC Pile Composite Foundation[J].Chinese Journal of Geotechnical Engineering,2008,30(9):1270-1275.
[5]雷金波,徐泽中,姜弘道,等.PTC型控沉疏桩复合地基试验研究[J].岩土工程学报,2005,27(6):652-656.
LEI Jin-bo,XU Ze-zhong,JIANG Hong-dao,et al.Experimental Studies on Composite Foundation with Sparse PTC Piles to Control Settlement[J].Chinese Journal of Geotechnical Engineering,2005,27(6):652-656.
[6]夏元友,芮 瑞.刚性桩加固软土路基竖向土拱效应的试验分析[J].岩土工程学报,2006,28(3):327-331.
XIA Yuan-you,RUI Rui.Experimental Analysis of Vertical Soil Arching Effect of Embankment Reinforced by Rigid Piles[J].Chinese Journal of Geotechnical Engineering,2006,28(3):327-331.
[7]赵明华,龙 军,张 玲.桩承加筋垫层复合地基桩土应力比分析[J].公路交通科技,2010,27(10):29-34.
ZHAO Ming-hua,LONG Jun,ZHANG Ling.Analysis of Pile-soil Stress Ratio of Pile-supported and Geogrid-reinforced Composite Foundation[J].Journal of Highway and Transportation Research and Development,2010,27(10):29-34.
[8]陈建峰,王 波,魏 静,等.加筋碎石桩复合地基路堤模型试验[J].中国公路学报,2015,28(9):1-8.
CHEN Jian-feng,WANG Bo,WEI Jing,et al.Model Test of Embankment on Composite Foundation Reinforced with Geosynthetic-encased Stone Columns[J].China Journal of Highway and Transport,2015,28(9):1-8.
[9]龚晓南.复合地基理论及工程应用[M].北京:中国建筑工业出版社,2002.
GONG Xiao-nan.Theory and Application of Composite Foundation[M].Beijing:China Architecture and Building Press,2002.
[10]CHEVALIER B,VILLARD P,COMBE G.Investigation of Load-transfer Mechanisms in Geotechnical Earth Structures with Thin Fill Platforms Reinforced by Rigid Inclusions[J].International Journal of Geomechanics,2011,11(3):239-250.
[11]BRIANCON L,SIMON B.Performance of Pile-supported Embankment over Soft Soil:Full-scale Experiment[J].Journal of Geotechnical and Geoenvironmental Engineering,2012,138(4):551-561.
[12]JENCK O,DIAS D,KASTNER R.Two-dimensional Physical and Numerical Modeling of a Pile-supported Earth Platform over Soft Soil[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(3):295-305.
[13]BLANC M,RAULT G,THOREL L,et al.Centrifuge Investigation of Load Transfer Mechanisms in a Granular Mattress Above a Rigid Inclusions Network[J].Geotextiles and Geomembranes,2013,36:92-105.
[14]OKYAY U S,DIAS D,THOREL L,et al.Centrifuge Modeling of a Pile-supported Granular Earth-platform[J].Journal of Geotechnical and Geoenvironmental Engineering,2014,140(2):217-235.
[15]BLANC M,THOREL L,GIROUT R,et al.Geosynthetic Reinforcement of a Granular Load Transfer Platform Above Rigid Inclusions:Comparison Between Centrifuge Testing and Analytical Modelling[J].Geosynthetics International,2014,21(1):37-52.
[16]ASIRI.Recommendations for the Design,Construction and Control of Rigid Inclusion Ground Improvement[M].Paris:Presses des Ponts,2012.
[17]王晶仁,葛忻声,白晓红,等.加筋褥垫层在灰土挤密桩复合地基中的应用[J].太原理工大学学报,2018,49(2):280-286.
WANG Jing-ren,GE Xin-sheng,BAI Xiao-hong,et al.Study on Reinforced Cushion in Lime Soil Compaction Pile Composite Foundation[J].Journal of Taiyuan University of Technology,2018,49(2):280-286.
[18]施有志.利用加筋垫层和粉喷桩联合处理软土地基[J].四川建筑,2004,24(6):47-49.
SHI You-zhi.Treatment of Soft Soil Foundation with Reinforced Cushion and Powder Jet Pile[J].Sichuan Architecture,2004,24(6):47-49.
[19]王晶仁,葛忻声,袁 慧,等.刚性基础下柔性桩加筋复合地基室内模型试验研究[J].广西大学学报(自然科学版),2019,44(1):108-114.
WANG Jing-ren,GE Xin-sheng,YUAN Hui,et al.Laboratory Model Test Study on Flexible Pile Reinforced Composite Foundation Under Rigid Foundation[J].Journal of Guangxi University(Natural Science Edition),2019,44(1):108-114.
[20]李运成,彭振斌,何 杰.刚性基础下土工格栅加筋碎石垫层变形特性试验研究[J].中南大学学报(自然科学版),2014,45(9):3244-3248.
LI Yun-cheng,PENG Zhen-bin,HE Jie.Experimental Study on Deformation Feature of Geogrids Reinforced Gravel Cushion with Rigid Foundation[J].Journal of Central South University(Science and Technology),2014,45(9):3244-3248.
[21]曹文昭,郑俊杰,严 勇.桩承式变刚度加筋垫层复合地基数值模拟[J].岩土工程学报,2017,39(增2):83-86.
CAO Wen-zhao,ZHENG Jun-Jie,YAN Yong.Numerical Simulation of Composite Foundation Using Pile-supported and Geosynthetics-reinforced Cushion with Variable Stiffness[J].Chinese Journal of Geotechnical Engineering,2017,39(S2):83-86.
[22]谭慧明,刘芝平,丁选明.加筋褥垫层对PCC桩复合地基承载特性影响足尺试验研究[J].岩石力学与工程学报,2014,33(12):2531-2538.
TAN Hui-ming,LIU Zhi-ping,DING Xuan-ming.Full Scale Model Test on Effect of Reinforced Cushion on Load Transmission Behavior of Composite Foundation of PCC Piles[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2531-2538.
[23]CAMP III W M,SIEGEL T C.Failure of a Column-supported Embankment over Soft Ground[C]//CHAN D H,LAW K T.Proceeding of the 4th International Conference on Soft Soil Engineering.Vancouver:CRC Press,2006:117-121.
[24]芮 瑞,孙 义,朱 勇,等.刚性基础下复合地基褥垫层细观工作机制[J].岩土力学,2019,40(2):445-454.
RUI Rui,SUN Yi,ZHU Yong,et al.Mesoscopic Working Mechanism of Cushion of Composite Foundation Under Rigid Slab[J].Rock and Soil Mechanics,2019,40(2):445-454.
[25]RUI R,HAN J,YE Y Q,et al.Load Transfer Mechanisms of Granular Cushion Between Column Foundation and Rigid Raft[J].International Journal of Geomechanics,2020,20(1):04019139.
[26]HUANG J,LE V,BIN-SHAFIQUE S,et al. Experimental and Numerical Study of Geosynthetic Reinforced Soil over a Channel[J].Geotextiles and Geomembranes,2015,43(5):382-392.
[27]BHANDARI A,HAN J.Two-dimensional Physical Modelling of Soil Displacements Above Trapdoors[J].Geotechnical Research,2018,5(2):68-80.
[28]芮 瑞,张 龙,孙 义,等.桩承式路堤土拱演化的二维钢棒相似土模型试验[J].中国公路学报,2017,30(10):8-16.
RUI Rui,ZHANG Long,SUN Yi,et al.2D Model Tests of Soil Arching Evolution in Pile Embankments Using Steel Rod Analogical Soil[J].China Journal of Highway and Transport,2017,30(10):8-16.
[29]芮 瑞,叶雨秋,陈 成,等.考虑墙壁摩擦影响的挡土墙主动土压力非线性分布研究[J].岩土力学,2019,40(5):1797-1804.
RUI Rui,YE Yu-qiu,CHEN Cheng,et al.Nonlinear Distribution of Active Earth Pressure on Retaining Wall Considering Wall-soil Friction[J].Rock and Soil Mechanics,2019,40(5):1797-1804.
[30]徐路畅,芮 瑞,张 龙,等.基于Trapdoor试验的双线隧道地表沉降预测公式探讨[J].岩土工程学报,2017,39(8):1470-1476.
XU Lu-chang,RUI Rui,ZHANG Long,et al.Prediction Formula for Surface Settlement in Double-line Tunnel Based on Trapdoor Tests[J].Chinese Journal of Geotechnical Engineering,2017,39(8):1470-1476.
[31]芮 瑞,万 亿,陈 成,等.加筋对桩承式路堤变形模式与土拱效应影响试验[J].中国公路学报,2020,33(1):41-50.
RUI Rui,WAN Yi,CHEN Cheng,et al.Experimental Investigation on Influences of Geosynthetic Reinforcement on Deformation Model Pattern and Soil Arching in Piled Embankments[J].Chinese Journal of Highways and Transport,2020,33(1):41-50.

相似文献/References:

[1]於慧,丁选明,刘汉龙,等.路堤荷载下现浇X形桩复合地基承载特性数值分析[J].建筑科学与工程学报,2013,30(02):87.
　YU Hui,DING Xuan-ming,LIU Han-long,et al.[J].Journal of Architecture and Civil Engineering,2013,30(01):87.
[2]芮 瑞,高 烽,刘 浩,等.基于Winkler地基离散元模型的复合地基褥垫层工作特性模拟[J].建筑科学与工程学报,2023,40(01):123.[doi:10.19815/j.jace.2021.09079]
　RUI Rui,GAO Feng,LIU Hao,et al.Simulation of working characteristics of composite foundation cushion based on Winkler foundation discrete element model[J].Journal of Architecture and Civil Engineering,2023,40(01):123.[doi:10.19815/j.jace.2021.09079]

备注/Memo

备注/Memo:

收稿日期:2021-03-11
基金项目:国家自然科学基金项目(51208403,51708438); 中铁建股份有限公司科技计划项目(218-C33)
作者简介:芮 瑞(1981-),男,安徽黄山人,教授,博士研究生导师,工学博士,E-mail:r.rui@whut.edu.cn。
通信作者:陈 成(1987-),男,湖北黄冈人,副教授,工学博士,E-mail:chengchen87@whut.edu.cn。

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更新日期/Last Update: 2021-02-10