九绵高速公路桑树坪大桥危岩病害研究与治理

Research and Treatment of Dangerous Rock Diseases of Sangshuping Bridge on Jiuzhaigou Mianyang Expressway

为进一步研究某工程危岩体的稳定性,降低工程实施对主体工程的影响和危害,以九绵高速公路桑树坪大桥左侧危岩为工程背景,在研究危岩所处斜坡形态、特征及破坏机理的基础上,定性分析危岩体整体稳定性,并进行定量计算。根据稳定性计算结果,考虑到暴雨工况下,需对开挖自然斜坡进行应力补偿,提出基于滑移破坏模式下对孤石危岩体底部进行嵌补加固,采取坡面锚固+柱板式挡墙嵌补+肋柱锚索加固的治理方案。该方案实施后效果显著,危岩体稳定性好,有效地降低了下方桥梁工程的风险。

In order to further study the stability of the dangerous rock mass of a project and reduce the impact and harm of the project implementation on the main works,taking the dangerous rock on the left side of Sangshuping Bridge of Jiuzhaigou Mianyang Expressway as the engineering background,on the ba⁃sis of studying the slope shape,characteristics and failure mechanism of the dangerous rock mass,the overall stability of the dangerous rock mass is qualitatively analyzed and quantitatively calculated.Accord⁃ing to the stability calculation results,considering that the stress compensation of the excavated natural slope is required under the rainstorm condition,the treatment scheme of"slope anchoring+column plate retaining wall embedding+rib column anchor cable reinforcement"is proposed to reinforce the bottom of the boulder dangerous rock body based on the sliding failure mode.After the implementation of the scheme,the effect is remarkable,the stability of the dangerous rock body is good,and the risk of the bridge project below is effectively reduced.