摘要
以香丽金沙江桥丽江岸边坡静动力稳定问题为研究对象,基于Phase2D软件,利用有限元强度折减,设计了无水、拟建水库运行低水位、水库正常蓄水位等3类工况,分别计算了上述每类工况0、0.10、0.15、0.20、0.25、0.30、0.35、0.40、0.45、0.50 g等10个拟静力法地震工况稳定性。经对比得到的安全系数和监测位移变化规律,所得主要结论如下:(1)香丽高速公路金沙江大桥丽江岸边坡的破坏模式为:后缘为陡倾结构面控制,剪入破坏发生在桥基和重力式锚碇位置区域;沿缓倾结构面滑移,前缘沿缓倾结构面剪出。(2)香丽高速公路金沙江大桥丽江岸边坡无水、拟建水库运行低水位和正常蓄水位工况下基于安全系数确定的临界水平地震加速度0.30 g;基于变形确定的临界值为0.20 g。(3)根据地震安全性评价,工程区地震动峰值加速度0.15~0.30 g,因此在容易发生破坏的位置要增补部分工程加固措施,以满足工程稳定性要求。(4)边坡静动力稳定性评价,需要同时考虑强度和变形控制标准,该边坡安全监控的预警值可参考无水工况下14 mm、低水位下9 mm、正常蓄水位下5 mm。
Static and seismic stability of Lijiang bank slope of Xianglijinshajiang Bridge is studied by strength reduction method based on Phase 2D.Three computing schemes with no water, lower water level and normal water level of proposed reservoir are designed. Each type contains ten quasi-static method computing conditions such as 0,0.10,0.15,0.20,0.25,0.30,0.35,0.40,0.45,0.50 g seismic load considered in the models for slope stability estimation. After safety factors and displacements are compared with each other, the following conclusions have been drawn. （1） The dope＇s fail mode is trailing edge controlled by steep structural plane which locates region of bridge base and gravity anchorage ; sliding along flat structural plane ; front edge shearing out of flat structural plane. （2） The critical horizontal earthquake accelera- tion of the slope static and seismic stability with different seismic loads under three types of reservoirs＂ running water level conditions is 0.30g done by limit safety factor analysis and 0.20 g determined by deformation analysis. （3） According to ground motion peak acceleration of engi- neer site being 0.15-0.30 g done by seismic safety evaluation, the slope is safe under the earthquake condition, but it needs to be reinforced by some engineering measures aiming to meet its engineering stability requirements. （4） The slope stability needs to meet the strength and de- formation standards, its pre-warning values for safe monitoring can refer to 14mm for no water condition, 9mm for lower water level and 5mm for normal water level.
出处
《中国农村水利水电》
北大核心
2017年第6期134-137,共4页
China Rural Water and Hydropower
基金
云南省交通科技项目[云交科2014(A)01]
国家自然科学基金项目(41202226
51608518
U01402231)
陆地交通气象灾害防治技术国家工程实验室开放基金项目(NELBP201501)
关键词
丽江岸边坡
位移
水平地震加速度
安全系数
Lijiang bank slope
displacement
horizontal earthquake acceleration
safety factor
