广元红岩嘉陵江大桥滑坡变形破坏机制及建桥适宜性研究
发布时间：2018-12-27 15:19
【摘要】：广元市元坝区位于四川盆地北部,广元市南部,属盆周丘陵向山区过渡地带,以低山为主,平均海拔900米。拟建广元红岩嘉陵江大桥是亭子口水库还建公路的控制性工程。广元红岩嘉陵江大桥左岸桥址所在部位原为一稳定性岸坡,适宜工程建设。但近年在红岩嘉陵江大桥桥址下游数百米范围内因人类工程活动,大桥滑坡坡脚开挖严重,导致坡体稳定性较差;在2013年,滑坡后缘在降雨的作用下出现拉张裂缝。在广元发生多期强降雨的影响下,坡体发生滑动的可能性非常大;同时,由于桥址位于库区,在亭子口水利g{纽库水位涨落的影响下,对坡体稳定性准确评价并做出针对性的工程措施就十分必要。本文采用广元红岩嘉陵江大桥滑坡桥址断面为模型,利用数值模拟方法,对滑坡的稳定性及建桥适宜性进行分析与评价。论文的主要工作及结论如下:1、对桥址区域的区域地质环境条件与桥位区的地质环境条件进行了介绍。桥位区左岸岸坡为顺倾坡,属于中型岩质牵引式滑坡。2、对滑坡的基本特征进行了介绍,并对其变形破坏机制进行分析。广元红岩嘉陵江大桥滑坡成因机制为滑移-拉裂。3、对大桥滑坡的稳定性进行定性分析,并利用有限元软件GeoStudio对滑坡在不同工况下的稳定性进行了判断,利用有限差分软件FLAC3D对滑坡在不同工况下的应力场与位移场进行了分析。综合分析表明,滑坡在天然、暴雨、地震及库水位骤降的工况下都是稳定的,在暴雨工况下滑坡的安全系数储备较小,提出了破面夯实+截排水沟+江边放冲刷石笼+监测网的治理措施。4、对广元红岩嘉陵江大桥进行适宜性研究,首先对桥位区域的岩体力学环境进行评价,然后对桥墩桩基一侧的滑坡推力与下滑力进行了计算,最后利用数值模拟方法,从滑坡推力、滑坡应力场与位移场三个方面对广元红岩嘉陵江大桥滑坡在不同工况的适宜性进行评价。综合分析表明:在建桥后,桥墩在库水位骤降的工况下位移最大,最大位移仅9mm,桥梁可以建设。
[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.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442
本文编号：2393265
[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.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442
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