【作者】 郭春艳；

【导师】 韩云山；

【作者基本信息】 中北大学 ， 工程力学， 2012， 硕士

【摘要】 在城市建设迅速发展，大量超高层建筑及地下空间的兴建与开发过程中，为满足建筑结构使用功能的各项要求，基坑开挖深度越来越深、面积越来越大。施工快捷、经济可靠的土钉支护技术在基坑工程中得到广泛的应用。然而单纯的土钉支护不适用于地下水位较高、淤泥质土等不良土质中。近年来在土钉支护的基础上发展出预应力锚杆（锚索）、土钉与水泥土搅拌桩、超前微桩等支护形式相结合的复合型土钉支护。复合土钉支护技术能够针对不同的地质条件灵活组合。但目前对复合土钉支护工作机理的研究不够深入，在工程中经常为保证基坑的安全稳定，人为提高基坑支护的安全系数，这样导致材料浪费，同时出现基坑失稳的工程事故还时有发生。本文结合某基坑实际工程，运用相似理论对室内模型试验进行设计，用MIDAS/GTS进行数值模拟，进一步通过工程监测数据对预应力锚杆复合土钉支护的工作机理进行研究，所得结论对类似工程的设计与施工有一定参考价值：（1）不同支护体系中土钉和预应力锚杆所受轴力的传递与分布规律；（2）不用施工阶段基坑水平位移均出现鼓肚子现象，最大水平位移发生在基坑的中下部；（3）预应力锚杆锚固段轴力为曲线分布，轴力随开挖深度增大。最大轴力出现在与自由段相连的地方，逐渐减小至远端最小。更多还原

【Abstract】 With the rapid development of city construction, large number of high-rise buildingconstruction and municipal underground space development, in order to meet the needs ofbuilding structure and the use of functional requirements, excavation depth is more and moredeeper, and the growing area.Soil nailing is a kind of economic and reliable, fast construction foundation bracing infoundation engineering technology, a large number of applications received. But the soilnailing support cannot be used for silt soil and other bad soil, underground water level and onthe deformation control strictly in foundation engineering. In recent years, soil nailing isdeveloped on the basis of soil nailing and cement soil mixing pile, prestressed anchor bolt,advanced micro pile supporting forms combining composite soil nailing support. Compositesoil nailing technology can be targeted at different sites and geological condition, suit one’smeasures to local conditions, flexible combination. But the composite soil nailing workingmechanism research is not deep enough, resulting in engineering is often appear in order toensure the safety and stability of the foundation, foundation support design personnel tocontinuously improve the safety coefficient, causing material waste; on the other hand,because the instability of foundation and the deformation caused by the engineering accidentbut when have happened.Combined with the actual project, using similarity theory to the indoor model test designstudy. And the prestressed anchor composite soil nailing by MIDAS / GTS finite analysissoftware for numerical simulation and engineering monitoring and contrast. The prestressedanchor composite soil nailing were studied thoroughly, the conclusion to the similarengineering design has a certain reference value: (1) Different modes of arrangement, in the supporting system of soil nailing and anchorthe axial force transmission and distribution;(2) Each construction stage, foundation horizontal displacement curve will appear" drumbelly" phenomenon, the maximum horizontal displacement of foundation is occurred, not thetop;(3) Prestressed anchor section of the axial force and the free section are connected tolocal maximum, minimum variation in the distal, axial force distribution curve, and with theincrease of depth of excavation.更多还原