發(fā)布時間：2018-02-10 01:31

  本文關(guān)鍵詞： 多層土工加筋體 巖溶塌陷 荷載傳遞 土拱效應(yīng) 張力膜理論　出處：《長沙理工大學》2014年碩士論文　論文類型：學位論文

【摘要】：巖溶地貌在我國有著廣泛的分布,巖溶洞穴頂板失穩(wěn)導致的地面塌陷具有漸進性和突發(fā)性,近年來地面塌陷導致路基失穩(wěn)、造成人員傷亡的報道日漸增多。巖溶區(qū)的高速公路如沒有對隱伏溶洞采取科學的防治措施,將會面臨很大的運營風險。對于小型的隱伏溶洞,土工加筋體防護巖溶塌陷是一種經(jīng)濟、實用、高效的工程防治措施。本文研究的多層土工加筋體不僅能夠增加防治巖溶路基塌陷的安全性,而且能夠有效的控制巖溶塌陷引發(fā)的地面沉降,在確保安全的前提下提升道路的行車舒適度。本文在理論研究的基礎(chǔ)上,設(shè)計了1：5的大比例室內(nèi)模型試驗,結(jié)合一種新型的土工格柵變形測試方法,對多層土工加筋體內(nèi)部土工格柵的變形和載荷特性、土拱效應(yīng)的發(fā)揮開展研究,并基于試驗研究成果提出了多層加筋體的設(shè)計方法。試驗得到了模型內(nèi)部關(guān)鍵測點的全程土壓力實測數(shù)據(jù)、土工格柵撓度數(shù)據(jù)以及土工格柵臨空段中間位置的應(yīng)變數(shù)據(jù)。綜合分析研究得到,(1)最底層格柵載荷與y/b的擬合公式;(2)多層土工加筋體內(nèi)部格柵的荷載傳遞系數(shù)；(3)模型試驗中土拱效應(yīng)的臨界高度；(4)土工加筋體模型試驗中土拱效應(yīng)的演化過程；(5)土拱效應(yīng)傳遞至多層土工加筋體的荷載。本文將多層土工加筋體分為“最底層格柵”和“上部格柵”分別進行研究,有利于剖析多層土工加筋體的工作機理。文中提出用拋物線擬合最底層格柵荷載與y/b的關(guān)系,以及提出的荷載傳遞參數(shù)能夠提供新的設(shè)計思路。土拱效應(yīng)傳遞至多層土工加筋體荷載的分析,揭示了多層土工加筋體在控制塌陷沉降上優(yōu)于單層土工加筋體的原因。
[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.
【學位授予單位】：長沙理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U416.16

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本文編號：1499341