本文選題：襯砌后空洞　切入點(diǎn)：地震響應(yīng)　出處：《中國(guó)礦業(yè)大學(xué)》2015年碩士論文

【摘要】：隧道襯砌與圍巖是一個(gè)相互作用的整體,但是相當(dāng)比例的襯砌后存在空洞現(xiàn)象并對(duì)隧道在地震下的穩(wěn)定性造成威脅�？斩刺幱陔[蔽環(huán)境其發(fā)現(xiàn)難、成因分析難和處置難,故對(duì)襯砌背后空洞對(duì)隧道動(dòng)力穩(wěn)定性影響規(guī)律的研究具有重要的學(xué)術(shù)價(jià)值和現(xiàn)實(shí)意義。本文采用理論、數(shù)值模擬與工程實(shí)例分析相結(jié)合的手段,研究了地震作用下有空洞隧道的動(dòng)力響應(yīng)規(guī)律,探討了空洞位置、尺寸等因素對(duì)襯砌與圍巖的受力影響規(guī)律,分析了隧道的震害機(jī)理,同時(shí)還提出了一種簡(jiǎn)化的地震響應(yīng)計(jì)算方法,主要得出了以下結(jié)論:(1)空洞使隧道襯砌向圍巖側(cè)凸出變形,襯砌截面安全系數(shù)降低,圍巖的塑性區(qū)域增加,空洞尺寸、隧道所受初始應(yīng)力越大該趨勢(shì)越明顯。(2)不同方向地震作用下剪切地震反應(yīng)最大豎向地震最小,隧道等地下結(jié)構(gòu)基本不影響巖土體的整體反應(yīng),結(jié)構(gòu)附加內(nèi)力由圍巖的差異變形產(chǎn)生。(3)地震作用下空洞處部分襯砌應(yīng)力增加并超過(guò)材料強(qiáng)度以致破壞,圍巖塑性應(yīng)變不斷累積以致圍巖壓力增大,當(dāng)?shù)卣鹆叶却笥冖葧r(shí)破壞明顯。(4)剪切地震下拱腰處空洞大于拱頂處影響,隧道初始受力越大則空洞影響程度越大,空洞環(huán)向角度與縱向長(zhǎng)度的影響明顯大于深度,且在隧道縱向有較明顯的端部效應(yīng)。(5)簡(jiǎn)化的計(jì)算方法方便可行,空洞的存在會(huì)放大地震的破壞作用。綜合認(rèn)為,在空洞環(huán)向角度大于30°,縱向長(zhǎng)度大于或等于環(huán)向線長(zhǎng)度時(shí),隧道在地震作用下更易產(chǎn)生破壞。該論文有圖132幅,表35個(gè),參考文獻(xiàn)118篇。
[Abstract]:Tunnel lining and surrounding rock are interacted as a whole, but a considerable proportion of the lining has cavities behind the lining, which threaten the stability of the tunnel under earthquake. It is difficult to find the cavities in the hidden environment, to analyze the causes and to deal with them. Therefore, it is of great academic value and practical significance to study the influence of the cavity behind the lining on the dynamic stability of the tunnel. In this paper, the method of combining theory, numerical simulation and engineering example analysis is adopted. In this paper, the dynamic response law of tunnel with holes under earthquake action is studied, and the influence of cavitation position and size on the stress of lining and surrounding rock is discussed, and the earthquake damage mechanism of tunnel is analyzed. At the same time, a simplified method for calculating seismic response is put forward. The main conclusions are as follows: 1) the cavity causes the tunnel lining to protrude and deform toward the surrounding rock side, the safety factor of the lining section decreases, the plastic region of the surrounding rock increases, and the cavity size increases. The larger the initial stress of tunnel is, the more obvious the trend is. (2) under the action of different direction earthquake, the maximum and vertical earthquake response of shear earthquake is minimum, and the underground structure such as tunnel has no effect on the overall response of rock and soil. The additional internal force of the structure is caused by the differential deformation of the surrounding rock. (3) under the action of earthquake, the stress of part of the lining in the cavity increases and exceeds the strength of the material, resulting in the failure, and the plastic strain of the surrounding rock accumulates and the pressure of the surrounding rock increases. When the seismic intensity is greater than 鈪，

本文編號(hào)：1672642