岩溶区高填方地基沉降控制技术研究

发布时间：2018-03-13 03:19

本文选题：岩溶区　切入点：高填方　出处：《贵州大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着西部地区经济的发展,机场建设也迎来了发展的黄金时期,由于西南地区的地理条件:高海拔、高填方和复杂的气候条件使得机场建设面临很多困难,特别是岩溶地区的地基沉降控制,但是对于岩溶区高填方的地基沉降控制目前为止都还没有一套完整的方法,没有一套成熟的理论。高填方地基沉降主要由两部分组成:一原地基沉降,二填筑体沉降,对于在高填方中如何能够有效的控制沉降已经成为了一个重要的研究课题。论文以威宁草海机场高填方地基为实例,结合现场试验结果,对填筑强夯和堆载预压两种处理措施进行了模拟研究,开展了对岩溶区高填方地基沉降控制技术的研究,主要研究内容和成果如下:1在现场做了强夯试验,分别在原地基和填筑体上施加不同夯击能,并对强夯前后的土体分别进行了颗粒、干密度和压实度的分析检测试验。通过现场试验,得出了灰岩碎石土的填筑强夯工艺:在3000kN·m夯击能作用下的最佳夯击数是11?12击,在2500kN·m夯击能作用下的最佳击数是10?11击,综合比较强夯前后试验检测得出:3000 kN·m的夯击效果好于2500 kN·m。2运用flac模拟软件,分别对夯击能为3000kN·m和2500kN·m进行了三维数值模拟分析,分析了在不同击数下的单击夯沉量、单点夯沉量和在不同深度下的最大主应力。认为在夯击能3000kN·m时,强夯的最佳击数是11击,达到的加固深度4m~4.5m;在2500kN.m时,强夯的最佳击数是10击,达到的加固深度4m左右。3分别对高度为20m、40m和60m的填筑物上堆载厚度2m、4m和6m的堆载物进行了三维数值模拟分析,并且比较不同状态下的压实效果,认为在填筑高度为20m,堆载厚度为6m时,能够达到较好的压实效果。
[Abstract]:With the economic development of the western region, the airport construction also ushered in a golden period of development. Due to the geographical conditions of the southwest region: high altitude, high fill and complex climatic conditions, the airport construction is facing many difficulties. Especially the control of foundation settlement in karst area, but there is not a complete set of methods to control the settlement of high fill foundation in karst area up to now. There is no mature theory. The settlement of high fill foundation is mainly composed of two parts: one is the settlement of the original foundation, the other is the settlement of the filling body. How to effectively control settlement in high fill has become an important research topic. This paper takes the high fill foundation of Weigning Caohai Airport as an example, combined with the field test results. The dynamic compaction and surcharge preloading treatment measures are simulated, and the settlement control technology of high fill foundation in karst area is studied. The main research contents and results are as follows: 1. Different ramming energy was applied on the in-situ foundation and the filling body, and the particle, dry density and compaction degree of the soil before and after the dynamic compaction were analyzed and tested respectively. The dynamic compaction technology of limestone gravel soil is obtained: the optimum number of compaction under the action of 3000kN 路m tamping energy is 11? 12 strikes, the best hit number under the action of 2500kN 路m tamping energy is 10? 11 strikes, compared with the tests before and after dynamic compaction, the results show that the tamping effect of: 3000kN 路m is better than that of 2500kN 路m.2 by using flac simulation software, and the three dimensional numerical simulation analysis of the tamping energy of 3000kN 路m and 2500kN 路m is carried out respectively, and the amount of single click ramming under different stroke numbers is analyzed. It is considered that the optimum hit number of dynamic compaction is 11 hits and the reinforcement depth is 4 mand 4.5 m at different depth, and the optimum hit number of dynamic compaction at 2500kN.m is 10 strokes, and the maximum principal stress at different depth is 3 000 KN 路m., and the optimum impact number of dynamic compaction is 11 hits and the reinforcement depth is 4 m and 4.5 m respectively, and the optimum impact number of dynamic compaction is 10 strokes at 2500kN.m. The reinforcement depth of 4m is about 4m. 3. The three dimensional numerical simulation analysis is carried out for the heaps with a thickness of 2mg 4m and 6m in height of 20m ~ 40m and 60m, respectively, and the compaction effects under different conditions are compared. It is considered that the compaction effect can be achieved when the filling height is 20 m and the heap-load thickness is 6 m.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU433

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