多元组合桩复合地基固结解析模型与解答  

Analytical models and solutions for consolidation of composite foundation with multiple types of reinforcements

作　　者：卢萌盟[1,2] 白垚 李红军 李东旭 李传勋 LU Mengmeng;BAI Yao;LI Hongjun;LI Dongxu;LI Chuanxun(State Key Laboratory of Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Zhejiang Real Estate Division,Greenland Holding Group,Hangzhou,Zhejiang 310015,China;Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116 [3]绿地浙江事业部,浙江杭州310015 [4]江苏大学土木工程与力学学院,江苏镇江212013

出　　处：《岩石力学与工程学报》2021年第S02期3301-3312,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51878657,52178373);江苏省高校“青蓝工程”资助。

摘　　要：近年来,复合地基技术呈现出由单一桩型向多元桩型联合使用的趋势。以塑料排水板联合不排水桩的多元复合地基为研究对象,针对桩体不同排列方式,采用不同的单元选取方式,提出3种组合桩复合地基固结解析模型,分别为外向水流模型(模型A)、内向水流模型(模型B)和双向水流模型(模型C),给出3种模型的统一解答,并进一步给出瞬时荷载、线性荷载、多级瞬时荷载和多级线性荷载4种情况下的详细解答。最后,采用参数敏感性分析法对多元组合桩复合地基固结性状进行研究。研究结果表明:相比以往解答,本文提出的3种模型可同时考虑排水板的井阻效应、涂抹作用和搅拌桩的扰动效应,其中双向流特征的模型C可适用于桩体任意规则布置的工况,具有极强的普适性;排水板井阻越小,排水板与不排水桩布置越密集,不排水桩压缩模量越高均会导致地基固结越快。In recent years,the technique of composite ground presents a trend from using a single column type to the combined use of multiple types of columns.This paper takes the combined composite ground improved by prefabricated vertical drains(PVDs)in combination with impervious columns as the research object.In view of the different arrangements of piles,different unit selection methods are employed.Accordingly,three analytical models for consolidation of the combined composite ground are proposed,including the outward flow model(Model A),the inward flow model(Model B)and the outward-inward bidirectional flow model(Model C).Then a unified solution for the three models is derived.Based on this,detailed solutions are further obtained for instantaneous loading,linear loading,multi-staged instantaneous loading and multi-staged linear loading.Finally,the consolidation behavior of the combined composite foundation is analyzed by a series of the parametrical analysis.The results show that the present solutions are able to consider comprehensively the effects of the well resistance and smear effect of the PVDs,as well as disturbance effect of the constructions of the impervious columns,compared to the previous studies.Moreover,the Model C is more universal to cover all the cases of regular layout patterns of the PVDs and the impervious columns.A smaller well resistance of the PVDs,or a denser layout of the PVDs and the impervious columns,or a higher compression modulus of the impervious columns,will lead to a faster consolidation of the combined composite ground.

关 键 词：基础工程:复合地基 组合桩 固结 排水板:环形单元 分析模型 

分 类 号：TU45[建筑科学—岩土工程]