泥炭土地基水泥搅拌桩承载特性现场试验研究  

Field Tests Study on Bearing Characteristic of Cement-soil Mixing Column-improved Peat Soil Foundation

作　　者：冯荣先 钟钙冰 金军良 梁鉴源 顾美湘 FENG Rongxian;ZHONG Gaibing;JIN Junliang;LIANG Jianyuan;GU Meixiang(China Communications Fourth Aviation Bureau First Engineering Co.,Ltd.,Guangzhou,Guangdong510450,China;School of Civil Engineering and Transportation,Guangzhou University,Guangzhou,Guangdong510006,China)

机构地区：[1]中交四航局第一工程有限公司,广东广州510450 [2]广州大学土木与交通工程学院,广东广州510006

出　　处：《施工技术（中英文）》2024年第19期35-39,共5页Construction Technology

基　　金：国家自然科学基金(51908150);广州市科技计划(SL2022A04J00985)。

摘　　要：滨海相泥炭土地基特有的腐蚀环境和侵蚀性离子,易对水泥土产生缓凝与侵蚀等不利作用。依托马来西亚东海岸铁路路基项目,采用水泥搅拌桩现场原位加固滨海相泥炭土地基,对不同龄期的水泥土钻芯取样并进行室内无侧限试验,同时开展多组单桩复合地基现场载荷试验,深入研究水泥搅拌桩的承载特性。试验结果表明:水泥土的无侧限抗压强度均大于1.0MPa,符合设计要求;外加剂的添加使桩体平均强度在中低水泥掺量时提高11.1%~19.5%,而高掺量时平均强度减少6.1%,水泥掺量的高低对高水灰比桩体强度影响较小;成桩时间大于340d的桩体受侵蚀性离子长期作用,强度衰减和劣化效应显著,平均强度减小19.4%;矿粉掺量的增加有利于提高水泥搅拌桩复合地基承载力,承载力最大增加28.6%。现场试验结果验证了水泥搅拌桩处治滨海相泥炭土地基的可行性,为该类型地基处治工法选取、设计和施工提供重要参考依据,同时应重视并长期监测水泥土强度衰减过程。Coastal peat soil composed of erosive and corrosive ions will retarder and erode the cement-soil.This paper uses This technique to improve coastal deep peat foundation based on the Malaysia East Coast Railway Project.After pile formation,the plate load tests on composite foundation and unconfined compressive tests on pile cored in different ages are conducted to thoroughly analyze the cement-soil mixing pile’s bearing and deformation capability.Test results show that all pile strength is greater than 1MPa under unconfined compression.Under the medium and low cement content,the average strength of cement-soil mixing pile with admixture is increased by about 11.1%to 19.5%,while that with high cement content is reduced by 6.1%.The effect of cement content on the average strength difference between piles with high water-cement ratio is small.Exceeding to 340days of pile formation,the pile strength has an average reduction of 19.4%due to the strength attenuation,deterioration effect,and long-term action of corrosive ion.The appropriate increase in mineral powder content is beneficial to the increase in bearing capacity of cement-soil mixing pile composite foundation,and the maximum growth of the bearing capacity is about 28.6%.field tests validates the feasibility of cement-soil mixing pile-reinforced coastal peat soil foundation.The research results can provide essential references for selecting construction methods and the project’s design and construction in peat foundation,and the attenuation procedure of cement-soil strength shall be measured and considered in detail.

关 键 词：地基 滨海相泥炭土 水泥搅拌桩 试验 承载力 

分 类 号：TU753[建筑科学—建筑技术科学]