库区公路倾倒岩体边坡高位错落变形机理及治理措施

Analysis of High-level Dislocation Deformation Mechanism and Treatment Measures of Toppling Rock Slope of Highway in Reservoir Area

倾倒岩体边坡是岩体向临空面发生弯曲变形的特殊岩质边坡,随着边坡开挖岩体卸荷,坡体应力重新分布,倾倒岩体折断面逐渐连通,坡体持续发生时效变形,易导致边坡变形失稳。依托澜沧江苗尾库区沿江公路倾倒岩体边坡实例工程,分析边坡高位错落变形特征及孕育过程,研究倾倒岩体边坡高位错落变形影响因素、失稳原因及变形机理;边坡治理遵循“锁口、强腰、固脚”的思路,采用削坡减载、主动预加固防护、挂网喷锚、堆渣压坡及截排水措施等进行综合治理,评价边坡加固前后的稳定性。结果表明:倾倒岩体边坡变形具有继承性,高位错落变形是前期倾倒岩体变形的延续;倾倒岩体变形边坡治理以主动预加固防护为主,削坡减载与锚固防护并重,限制倾倒变形岩体应力松弛与蠕变,可为类似边坡病害分析与治理提供借鉴和参考。

Toppling rock slope is a special rock slope with bending deformation of rock mass to the free face.With the unloading of rock mass during slope excavation,the stress redistribution of slope,the fracture surfaces of toppling rock are gradually connected,and the time-dependent deformation of slope continues to occurrence,which easily leads to slope deformation instability.Relying on the example project of toppling rock slope along the highway in Miaowei reservoir area of Lancang River in Yunnan Province,the characteristics and evolution process of high-level dislocation deformation of slope are analyzed,and the influencing factors,instability causes and deformation mechanism of high-level dislocation deformation of toppling rock slope are studied.The slope management follows the idea of“locking the slope groove,strengthening the waist and consolidating the foot”,and adopts comprehensive management such as slope cutting and unloading,active pre-reinforcement protection,hanging net spraying anchor,slag pile pressure slope and water interception and drainage measures to evaluate the stability of the slope before and after reinforcement.The results show that the deformation of the toppling rock slope is inherited,and the high-level dislocation deformation is the continuation of the original toppling rock mass deformation.The treatment of toppling rock mass deformation slope is mainly based on active pre-reinforced protection,and both cutting slope and unloading and anchorage protection are used to limit the stress relaxation and creep of toppling rock mass,which can provide reference for the similar slope disease analysis and treatment.