【作者】 李新；

【导师】 黄华；

【作者基本信息】 长安大学 ， 项目管理（专业学位）， 2019， 硕士

【摘要】 随着城市建设的迅猛发展,新建道路工程的基坑开挖不可避免地会加剧邻近建筑物及其地基的变形,进而影响其安全可靠度。针对此问题,本文以西安沣渭新区后围寨工程尚航路北段辅道路基坑工程为背景,首先利用理正深基坑软件对支护桩结构进行设计计算,然后运用ABAQUS软件建立三维实体模型,对基坑开挖进行全过程模拟,并对两类方法的分析结果进行比较分析;基于实际施工过程,进行施工监控,与数值分析结果进行对比,研究超近距离路基基坑分层开挖全过程对骨灰塔支护体系的沉降和变形影响。研究所取得的主要结果如下:(1)理正深基坑软件有着计算方便、操作简单、节省前处理时间等优点,但是欠缺理论基础,在设计计算过程中有一定局限性,如支护桩的桩长、桩径、桩间距、刚度等参数不能准确的模拟实际情况,且对支护桩的排列方式也有一定限制。(2)采用ABAQUS模型能够较好的完成超近距离基坑开挖对周边环境变形影响的数值模拟分析,同时也证明本工程采用的支护方案及施工方法,能够对超近距离基坑开挖对周边环境变形的影响起到有效控制作用。(3)在土压力作用下,抗滑桩桩身弯矩曲线呈桩端小、中间大的形状,桩身弯矩随基坑开挖深度增大而减小,出现反弯矩后又随基坑开挖深度先增大后减小至零,随着基坑继续开挖,弯矩总体还将继续增大。(4)挡墙及被支挡土体的最大水平位移值为12.1mm,最大沉降值为5.0mm,满足相关规定要求。(5)道路基坑开挖过程中及工后,骨灰塔塔基地梁的差异沉降幅度约1mm,远小于最大允许值10mm,基坑开挖对骨灰塔的安全性和耐久性均没有影响。更多还原

【Abstract】 Due to the rapid development of the cities builds,it is inevitable that deformation of adjacent buildings and their foundations because of the foundation pit excavation of new road engineering,and then affecting their safety and reliability.For this reason,the influence of the whole process of layered excavation of the adjacently foundation pit on the settlement and deformation of the Ashes tower supporting system is studied in this paper.Based on the auxiliary road foundation pit of the northern section of Shanghang Road,Houweizhai Project,Xi’an Fuxin District,this study designs and calculates the soldier pile system by the software of Lizheng Deep foundation pit.In addition,a 3D solid model is established by ABAQUS,which simulates the whole process of foundation pit excavation.Then compare and analyze the results of the two methods that from the monitoring of the actual construction process and numerical analysis.The main achievements are as follows.(1)Leading software has ample advantages,including convenient calculation,easy operation and time saving of pretreatment.While,there are also same deficiency in theoretical foundation and certain limitations in the design calculation process.The parameters of retaining pile in length,diameter,spacing and stiffness cannot accurately simulate the actual situation.Besides,there are also restrictions on the arrangement of the retaining piles.(2)It is a better choice to utilize the ABAQUS software to simulate the influence of foundation excavation with super close distance on deformation in the surrounding environment.Meanwhile,the model analytical results indicated that supporting scheme and construction technology for this project can effectively control the influence of foundation excavation with super close distance on deformation in the surrounding environment.(3)The moment curve of anti-slide pile shaft is small at the end of the pile and large in the middle.Meanwhile,it also decreases with the increase of excavation depth of foundation pit,while the overall moment will continue to increase with the increase of excavation depth of foundation pit.(4)The maximum horizontal displacement of the retaining wall and the retaining soil is 12.1mm,and the maximum sedimentation value is 5.0mm satisfied with the codes.(5)During and after the excavation of the road foundation pit,the sedimentation value of ground beam in ashes tower is about 1mm,which is far less than the maximum allowable value of 10 mm.This indicated that foundation pit excavation has no effect on the safety and durability of the ashes tower.更多还原