摘要
浙江东部某海岛厂区在竣工交付后,主体结构完好,但厂区道路与室内外地坪却发生了大面积整体沉降,导致路面开裂、地表塌陷及附属设施损坏,造成了严重损失。该案例是深厚软土地区工后沉降超限的典型代表。为探明原因,采用了多种常规地质勘测手段,如室内试验(对比工前工后土体物理力学指标)、孔压静力触探(CPTU)、十字板剪切试验(VST)等,以判定软土的固结情况与强度指标等。重点针对该项目所采用的预压法、水泥土搅拌桩复合地基及桩-网复合地基这3种地基处理方式,系统分析了导致沉降超限的主要影响因素。分析表明:土层性质复杂多变且分布不均、软土欠固结、预压处理时间不足、水泥土搅拌桩桩端未进入坚硬持力层是引发沉降的主因;同时,施工中的沉桩效应也对沉降产生了不利影响。研究方法与结论对深厚软土地区的类似工程建设具有借鉴与参考价值。
After the completion and delivery of a factory in a coastal industrial area on an island in eastern Zhejiang,the main structure was intact,but large-scale overall settlement occurred in the internal roads and indoor and outdoor floors of the plant.Cracking of roads,surface collapse,and damage to facilities caused significant economic losses,representing a typical case of excessive post-construction settlement in a deep soft soil area.To investigate the causes,various conventional geological survey methods were employed,including laboratory tests(comparing physical and mechanical indicators of soil before and after construction),piezocone penetration tests(CPTU),and vane shear tests(VST),to determine the consolidation degree and strength parameters of the soft soil.In view of the three ground treatment methods adopted in the project,including the preloading method,composite foundation with cement deep mixed columns,and pile-net composite foundation,the influencing factors of ground subsidence were studied.The study found that the main factors of ground subsidence were the diversity and heterogeneity of soil types,the under-consolidation characteristics of soft soil,insufficient preloading duration,and the failure of cement-soil mixing columns tips to penetrate into the hard bearing layer.The adverse effects induced by pile installation were also discussed,and pile driving was also considered to be one of the influencing factors of ground subsidence.The research methods and results in this paper have certain engineering significance,and similar projects in deep soft soil areas may benefit from or refer to the findings of this study.
作者
何康
雷元
白云鹏
雷胜全
姜记冰
刘伟惠
董泽彬
HE Kang;LEI Yuan;BAI Yunpeng;LEI Shengquan;JIANG Jibing;LIU Weihui;DONG Zebin(Wuhan Harbor Quality Inspection Co.,Ltd.,Wuhan 430056,Hubei,China;Nantong Guanglian Geotechnical Survey and Design Co.,Ltd.,Nantong 226001,Jiangsu,China;Hai’an Construction Engineering Construction Drawing Review Office,Nantong 226600,Jiangsu,China;Nantong Construction Group Co.,Ltd.,Nantong 226001,Jiangsu,China;Zhangjiang(Group)Co.,Ltd.,Shanghai 201203,China;SGIDI Engineering Consulting(Group)Co.,Ltd.,Shanghai 200093,China)
出处
《地基处理》
2026年第2期193-201,212,共10页
Journal of Ground Improvement
基金
国家自然科学基金项目(41772293)。
关键词
深厚软土地区
工后沉降
欠固结土
预压法
水泥土搅拌桩复合地基
桩-网复合地基
deep soft soil area
post-work settlement
under-consolidated soil
preloading method
composite foundation with cement deep mixed columns
pile-net composite foundation
