碎石桩红黏土复合地基承载力与变形特性分析  

Bearing Capacity and Deformation Characteristics of Gravel Pile Red Clay Composite Foundation

作　　者：任佳丽[1] 龚泉 胡胜刚[1] 谭国强 REN Jiali;GONG Quan;HU Shenggang;TAN Guoqiang(Yangtze Riter Scientific Research Institute,Wuhan,Hubei 430010,China;Wuhan Changjiang Ke Chuang Technology Development Co.,Ltd.,Wuhan,Hubei 430010,China;CAAC New Era Airport Design&Research Institute,Guangzhou Briutch,Guangzhou,Cuangdong 510405,China)

机构地区：[1]长江水利委员会长江科学院,湖北武汉430010 [2]武汉长江科创科技发展有限公司,湖北武汉430010 [3]上海民航新时代机场设计研究院有限公司广州分公司,广东广州510405

出　　处：《水利与建筑工程学报》2023年第1期160-165,共6页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金项目(51979009);中央级公益性科研院所基本科研业务费专项资金资助项目(CKSF2021460/YT)。

摘　　要：在天然红黏土地基上进行高填方机场建设,其沉降与稳定性难以满足机场控制标准。碎石桩复合地基具有加速地基固结沉降和提高地基承载力的作用,可较好应用在红黏土地基处理中,但其作用机理不明确。基于西南某高填方机场的红黏土地基,通过室内试验和原位测试,研究碎石桩处理前后红黏土的物理力学特性,得出置换率为7.0%时,碎石桩复合地基以排水固结为主要加固机理,处理28 d未加载条件下地基承载力提高了23.7%;利用ABAQUS有限元软件对红黏土未处理地基和碎石桩复合地基在填筑荷载下的变形特性和孔隙水压力消散情况进行数值模拟,得出天然红黏土地基固结速率非常缓慢,工后沉降不能满足运行期道面运行要求,采用碎石桩处理后,红黏土软弱地基的排水固结速率得到大大提高,施工期固结度可完成96.0%。研究结果得到了现场监测资料的验证,可为类似工程提供参考。The settlement and stability of high-fill airport construction on natural red clay foundation are difficult to meet the airport control standards. The gravel pile composite foundation can accelerate the consolidation settlement and improve the bearing capacity of the foundation, but the mechanism of action is unclear. Based on a high-fill airport in southwest China, the physical and mechanical properties of red clay before and after gravel pile treatment were analyzed through laboratory tests and in-situ tests. The results show that when the displacement rate is 7.0%, the gravel pile composite foundation takes drainage consolidation as the main reinforcement mechanism, and the foundation bearing capacity increases by 23.7% after 28 days of treatment. ABAQUS is used to simulate the deformation characteristics and pore water pressure dissipation of untreated red clay foundation and composite foundation with crushed stone pile under filling load. The results show that the consolidation rate of natural red clay foundation is very slow and the post-construction settlement cannot meet the requirements. The drainage consolidation rate of red clay foundation is greatly increased after the treatment of gravel pile, and the consolidation degree can be completed 96.0% during the construction period. The research results are verified by on-site monitoring data, which can provide technical support for similar projects.

关 键 词：红黏土 碎石桩 承载力 变形特性 土工试验 数值计算 

分 类 号：TU43[建筑科学—岩土工程]