本文選題：大斷面公路隧道 + 富水巖溶地層��； 參考：《西南交通大學(xué)》2015年碩士論文

【摘要】：近年來隨著我國公路交通事業(yè)的不斷發(fā)展,以及交通量的日益增長,三車道及其以上的大斷面特長公路隧道不斷涌現(xiàn)。在我國西南地區(qū),特長隧道往往會穿越富水巖溶地層,對于“以排為主”的隧道,如遇陣發(fā)性大量降雨或者隧道排水系統(tǒng)堵塞失效的情況下,隧道結(jié)構(gòu)將承受一定的水壓力,如遇襯砌背后存在空洞,將使結(jié)構(gòu)受力復(fù)雜化并危及隧道結(jié)構(gòu)的安全,因此,亟需開展扁平大斷面隧道結(jié)構(gòu)的受力特性研究。本論文依托重慶雙碑隧道工程,通過結(jié)構(gòu)內(nèi)力現(xiàn)場測試、室內(nèi)縮尺試驗以及數(shù)值模擬相結(jié)合的手段,對扁平特大斷面隧道的結(jié)構(gòu)內(nèi)力特點(diǎn)和破壞形態(tài)進(jìn)行了研究,主要研究內(nèi)容和成果如下：1)利用依托工程,選取了Ⅲ、Ⅳ、Ⅴ級圍巖富水地層代表性斷面進(jìn)行襯砌結(jié)構(gòu)內(nèi)力現(xiàn)場測試,分別對“以堵為主”和“以排為主”地段的隧道結(jié)構(gòu)的內(nèi)力和安全系數(shù)進(jìn)行了對比,分析了三車道和緊急停車帶斷面的結(jié)構(gòu)的安全性,得出了隧道結(jié)構(gòu)安全性的控制部位。2)開展縮尺模型試驗,利用圍巖壓力加載裝置和非圓形斷面均勻水壓加載裝置分別模擬圍巖壓力和水壓力的作用,考慮不同水頭高度、襯砌背后空洞位置等影響因素,對三車道及緊急停車帶斷面襯砌結(jié)構(gòu)受力進(jìn)行了測試,分析了隧道結(jié)構(gòu)破壞形態(tài),得出了結(jié)構(gòu)受力特點(diǎn)、結(jié)構(gòu)內(nèi)力隨水壓力的變化規(guī)律,給出了類似結(jié)構(gòu)出現(xiàn)裂縫時的臨界水頭高度建議值。3)基于流固耦合機(jī)理,運(yùn)用有限差分軟件FLAC3D建立了15組數(shù)值模型,假定隧道排水系統(tǒng)失效,考慮不同水壓力的作用(0/10m/20m/30m),對二次襯砌背后水壓力、襯砌內(nèi)力及安全系數(shù)進(jìn)行了計算,得出了二次襯砌背后水壓力的分布規(guī)律、襯砌內(nèi)力分布及變化規(guī)律和安全系數(shù)變化規(guī)律,分析了襯砌背后空洞位置以及拱頂和邊墻空洞的大小對隧道結(jié)構(gòu)的影響。
[Abstract]:In recent years, with the continuous development of highway traffic and the increasing traffic volume in our country, the large-section and super-long highway tunnels with three lanes and more have been emerging. In southwest China, super-long tunnels often pass through water-rich karst formations. For tunnels with "drainage", such as sudden heavy rainfall or failure of tunnel drainage system, the tunnel structure will bear a certain water pressure. If there is a hole behind the lining, it will complicate the structure and endanger the safety of the tunnel structure. Therefore, it is urgent to carry out research on the mechanical characteristics of the flat and large section tunnel structure. In this paper, based on Chongqing double-tablet tunnel project, the characteristics of structural internal force and failure pattern of the large section tunnel are studied by means of field test of structural internal force, indoor scale test and numerical simulation. The main research contents and results are as follows: (1) based on the support project, the representative sections of grade 鈪，

本文編號：1843939