【摘要】：廣元市元壩區(qū)位于四川盆地北部,廣元市南部,屬盆周丘陵向山區(qū)過渡地帶,以低山為主,平均海拔900米。擬建廣元紅巖嘉陵江大橋是亭子口水庫還建公路的控制性工程。廣元紅巖嘉陵江大橋左岸橋址所在部位原為一穩(wěn)定性岸坡,適宜工程建設(shè)。但近年在紅巖嘉陵江大橋橋址下游數(shù)百米范圍內(nèi)因人類工程活動(dòng),大橋滑坡坡腳開挖嚴(yán)重,導(dǎo)致坡體穩(wěn)定性較差;在2013年,滑坡后緣在降雨的作用下出現(xiàn)拉張裂縫。在廣元發(fā)生多期強(qiáng)降雨的影響下,坡體發(fā)生滑動(dòng)的可能性非常大;同時(shí),由于橋址位于庫區(qū),在亭子口水利g{紐庫水位漲落的影響下,對(duì)坡體穩(wěn)定性準(zhǔn)確評(píng)價(jià)并做出針對(duì)性的工程措施就十分必要。本文采用廣元紅巖嘉陵江大橋滑坡橋址斷面為模型,利用數(shù)值模擬方法,對(duì)滑坡的穩(wěn)定性及建橋適宜性進(jìn)行分析與評(píng)價(jià)。論文的主要工作及結(jié)論如下:1、對(duì)橋址區(qū)域的區(qū)域地質(zhì)環(huán)境條件與橋位區(qū)的地質(zhì)環(huán)境條件進(jìn)行了介紹。橋位區(qū)左岸岸坡為順傾坡,屬于中型巖質(zhì)牽引式滑坡。2、對(duì)滑坡的基本特征進(jìn)行了介紹,并對(duì)其變形破壞機(jī)制進(jìn)行分析。廣元紅巖嘉陵江大橋滑坡成因機(jī)制為滑移-拉裂。3、對(duì)大橋滑坡的穩(wěn)定性進(jìn)行定性分析,并利用有限元軟件GeoStudio對(duì)滑坡在不同工況下的穩(wěn)定性進(jìn)行了判斷,利用有限差分軟件FLAC3D對(duì)滑坡在不同工況下的應(yīng)力場(chǎng)與位移場(chǎng)進(jìn)行了分析。綜合分析表明,滑坡在天然、暴雨、地震及庫水位驟降的工況下都是穩(wěn)定的,在暴雨工況下滑坡的安全系數(shù)儲(chǔ)備較小,提出了破面夯實(shí)+截排水溝+江邊放沖刷石籠+監(jiān)測(cè)網(wǎng)的治理措施。4、對(duì)廣元紅巖嘉陵江大橋進(jìn)行適宜性研究,首先對(duì)橋位區(qū)域的巖體力學(xué)環(huán)境進(jìn)行評(píng)價(jià),然后對(duì)橋墩樁基一側(cè)的滑坡推力與下滑力進(jìn)行了計(jì)算,最后利用數(shù)值模擬方法,從滑坡推力、滑坡應(yīng)力場(chǎng)與位移場(chǎng)三個(gè)方面對(duì)廣元紅巖嘉陵江大橋滑坡在不同工況的適宜性進(jìn)行評(píng)價(jià)。綜合分析表明:在建橋后,橋墩在庫水位驟降的工況下位移最大,最大位移僅9mm,橋梁可以建設(shè)。
[Abstract]:Yuanba District of Guangyuan City is located in the northern part of Sichuan Basin and the southern part of Guangyuan City. It belongs to the transition zone from the pelvic hilly region to the mountainous area with an average elevation of 900 meters. The planned construction of the Guangyuan Hongyan Jialing River Bridge is a controlling project for the Tingzikou Reservoir and the highway. The site of the left bank of Guangyuan Hongyan Jialing River Bridge is a stable bank slope, which is suitable for engineering construction. However, in recent years, due to human engineering activities, the excavation of the slope foot of the bridge is serious in the lower reaches of the bridge site of Hongyan Jialing River Bridge, which leads to the poor stability of the slope body. In 2013, tensile cracks occurred in the rear edge of the landslide under the action of rainfall. Under the influence of several periods of heavy rainfall in Guangyuan, the possibility of slope sliding is very high. At the same time, because the bridge site is located in the reservoir area, under the influence of the water level fluctuation of the water conservancy g {new reservoir, it is very necessary to evaluate the stability of the slope body accurately and make the corresponding engineering measures. In this paper, the stability and suitability of the landslide are analyzed and evaluated by using the section of the landslide site of the Guangyuan Hongyan Jialing River Bridge as the model and the numerical simulation method. The main work and conclusions are as follows: 1. The regional geological environment conditions of the bridge site and the geological environment conditions of the bridge site are introduced. The slope on the left bank of the bridge is a incline slope, which belongs to the medium rock tractive landslide. 2. The basic characteristics of the landslide are introduced and the mechanism of its deformation and failure is analyzed. The genetic mechanism of the landslide of Guangyuan Hongyan Jialing River Bridge is sliding-tension crack. 3. The stability of the bridge landslide is qualitatively analyzed, and the stability of the landslide under different working conditions is judged by the finite element software GeoStudio. The stress field and displacement field of landslide under different working conditions were analyzed by finite difference software FLAC3D. The comprehensive analysis shows that the landslide is stable under the conditions of natural, heavy rain, earthquake and sudden drop of reservoir water level, and the safety coefficient reserve of landslide is small under the condition of heavy rain. This paper puts forward the measures for controlling the monitoring network of ramming the broken surface along the drainage ditch and draining the rock cage along the river. (4) the suitability of the Guangyuan Hongyan Jialing River Bridge is studied. Firstly, the rock mass mechanics environment in the bridge area is evaluated. Then, the landslide thrust and sliding force on one side of the pile foundation of bridge pier are calculated. Finally, the landslide thrust is calculated by using numerical simulation method. Three aspects of landslide stress field and displacement field were used to evaluate the suitability of Guangyuan Hongyan Jialing River Bridge landslide under different working conditions. The comprehensive analysis shows that after the construction of the bridge, the maximum displacement of the pier is only 9mm under the condition of sudden drop of reservoir water level, so the bridge can be built.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U442

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本文編號(hào)：2393265