考虑变井阻的多元复合地基固结理论研究  

STUDY ON THE CONSOLIDATION BEHAVIORS OF MULTIREINFORCEMENT COMPOSITE FOUNDATION CONSIDERING TIME-DEPENDENT WELL RESISTANCE

作　　者：白垚 卢萌盟 杨康 赵明 BAI Yao;LU Meng-meng;YANG Kang;ZHAO Ming(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory of Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Zhejiang Wood and Stone Construction Project Management Consulting Co.,Ltd.,Hangzhou,Zhejiang 311199,China)

机构地区：[1]中国矿业大学力学与土木工程学院,江苏徐州221116 [2]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 [3]浙江木石建设项目管理咨询有限公司,浙江杭州311199

出　　处：《工程力学》2024年第6期44-54,共11页Engineering Mechanics

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

摘　　要：该文以塑料排水板联合水泥搅拌桩多元复合地基为研究对象,通过假定排水板的渗透系数随时间呈指数型衰减,考虑了排水板在固结过程中的淤堵效应对地基固结性状的影响。同时,该文还考虑排水板的涂抹效应、水泥搅拌桩的扰动效应以及土体的径-竖向耦合渗流,推导得出多元复合地基的固结控制方程及其解答。通过与已有解答和现场试验的对比分析,验证该文解答的正确性。最后,采用参数敏感性分析法对多元复合地基固结性状进行研究。研究结果表明:复合地基井阻因子θ对固结后期影响较大,当θ值较大时,径向渗流由于排水板的淤堵效应将提前终止,最终仅由竖向渗流使得地基达到完全固结;初始渗透系数k_0越大,井阻因子θ越小,涂抹作用越弱,板和桩的置换率越高,复合地基固结速率就越快。This paper studies the multi-reinforcement composite foundation improved by prefabricated vertical drains(PVDs)with cement mixing piles,and the influence of clogging effect of PVDs is considered by assuming the permeability coefficient of PVDs decays exponentially with time.In addition,the smear effect of PVDs,the disturbance effect of the cement mixing pile,and the coupled radial-vertical flow within the soil are considered.The governing equations of consolidation of the multi-reinforcement composite foundation and the corresponding solutions are derived.The solutions is verified by comparison with several existing solutions and three field tests.Finally,the consolidation behavior of the multi-reinforcement composite ground is analyzed by a series ofθparametrical analysis.The results show the well resistance factor has a great influence on the later stage ofθconsolidation process.A large value for will result in the radial flow ceasing in advance.Consequently,the consolidation will be completed only via the vertical flow.The following factors will lead to a faster consolidation k0rate,including a larger value of the initial permeability coefficient,a smaller value for the well resistance factorθ,weaker smearing effect,and larger replacement ratios of PVDs and piles.

关 键 词：多元复合地基 排水板 变井阻效应 固结 淤堵效应 

分 类 号：TU47[建筑科学—结构工程]