多层土工加筋体防治岩溶路基潜在塌陷的理论与试验研究

发布时间：2018-02-10 01:31

本文关键词： 多层土工加筋体岩溶塌陷荷载传递土拱效应张力膜理论　出处：《长沙理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：岩溶地貌在我国有着广泛的分布,岩溶洞穴顶板失稳导致的地面塌陷具有渐进性和突发性,近年来地面塌陷导致路基失稳、造成人员伤亡的报道日渐增多。岩溶区的高速公路如没有对隐伏溶洞采取科学的防治措施,将会面临很大的运营风险。对于小型的隐伏溶洞,土工加筋体防护岩溶塌陷是一种经济、实用、高效的工程防治措施。本文研究的多层土工加筋体不仅能够增加防治岩溶路基塌陷的安全性,而且能够有效的控制岩溶塌陷引发的地面沉降,在确保安全的前提下提升道路的行车舒适度。本文在理论研究的基础上,设计了1：5的大比例室内模型试验,结合一种新型的土工格栅变形测试方法,对多层土工加筋体内部土工格栅的变形和载荷特性、土拱效应的发挥开展研究,并基于试验研究成果提出了多层加筋体的设计方法。试验得到了模型内部关键测点的全程土压力实测数据、土工格栅挠度数据以及土工格栅临空段中间位置的应变数据。综合分析研究得到,(1)最底层格栅载荷与y/b的拟合公式;(2)多层土工加筋体内部格栅的荷载传递系数；(3)模型试验中土拱效应的临界高度；(4)土工加筋体模型试验中土拱效应的演化过程；(5)土拱效应传递至多层土工加筋体的荷载。本文将多层土工加筋体分为“最底层格栅”和“上部格栅”分别进行研究,有利于剖析多层土工加筋体的工作机理。文中提出用抛物线拟合最底层格栅荷载与y/b的关系,以及提出的荷载传递参数能够提供新的设计思路。土拱效应传递至多层土工加筋体荷载的分析,揭示了多层土工加筋体在控制塌陷沉降上优于单层土工加筋体的原因。
[Abstract]:Karst landforms are widely distributed in China. The ground collapse caused by roof instability in karst caves is gradual and sudden. In recent years, ground collapse has resulted in subgrade instability. Reports of casualties are increasing day by day. If the highway in karst areas does not take scientific measures to prevent and cure hidden caverns, it will face great operational risks. Geotechnical reinforcement is an economical, practical and efficient engineering measure to prevent karst collapse. The multi-layer geo-reinforced body studied in this paper can not only increase the safety of preventing karst subgrade collapse, but also can prevent the collapse of karst roadbed. Moreover, it can effectively control the land subsidence caused by karst collapse and raise the driving comfort of the road on the premise of ensuring safety. Based on the theoretical research, a large scale indoor model test of 1: 5 is designed in this paper. Combined with a new method for measuring the deformation of geogrid, the deformation and load characteristics of the geogrid in multi-layer geogrid are studied, and the effect of soil arch on the deformation and load of the geogrid is studied. Based on the experimental results, the design method of multi-layer reinforced body is proposed. The deflection data of geogrid and the strain data of the middle position near the space of geogrid. A comprehensive analysis is made to get the fitting formula of the bottom grid load and yr / b) the load transfer coefficient of the grille in the multilayer geogrid is 3). The critical height of soil arch effect in model test is 4) the evolution process of soil arch effect in model test is 5) the load transfer from soil arch effect to multilayer geotextile reinforced body. In this paper, the multilayer earth reinforced body is divided into "bottom layer lattice". The "grid" and "upper grid" were studied respectively, In this paper, parabola is proposed to fit the relation between the bottom grid load and yr / b. The analysis of the transfer effect of soil arch to the load of multi-layer reinforced body reveals the reason that the multi-story reinforced body is superior to single-layer reinforced body in controlling subsidence.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.16

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