黄土地区拱形骨架边坡防护机理及结构优化

Protection Mechanism and Structural Optimization of Arched Framework Slope in Loess Region

黄土边坡由于水敏性等特殊性质,降雨作用会对边坡产生不利影响,通常需要设置边坡防护结构。通过分析不同尺寸参数的拱形骨架结构对边坡稳定性的影响,得到安全性与经济性相适应的骨架结构尺寸。研究表明:不同尺寸的骨架结构可能出现2种破坏模式,且存在转化阈值l_(sp)。当竖骨架净距l_(v)<l_(sp)时,为土体剪切破坏模式;当l_(v)>l_(sp)时,为骨架结构破坏模式。浅层边坡结构安全系数随骨架宽度和埋设深度增大而增大,随骨架纵、横向净距增大而减小。其中,埋设深度厚度和竖骨架净距对安全系数的影响更显著。当l_(v)=l_(sp)时,单位面积所需防护材料用量最少。此时,满足安全系数、结构强度,且符合施工构造要求的骨架参数为最优解。

Due to special properties such as water sensitivity,the loess slope will be adversely affected by rainfall.Therefore,it is usually necessary to set up slope protection structures.By analyzing the influence of arch framework structure with different size parameters on slope stability,the size of framework structure suitable for safety and economy is obtained.The results show that there may be two failure modes in different sizes of framework structures,and there is a transformation threshold l_(sp).When the longitudinal clear distance of the framework l_(v)<l_(sp),it is the shear failure mode of the soil mass;when l_(v)>l_(sp),it is the failure mode of the framework structure.The safety factor of shallow slope structure increases with the increase of framework width and burial depth,and decreases with the increase of longitudinal and transverse clear distance of framework.Among them,the burial depth thickness and the longitudinal clear distance of the framework have a more significant influence on the safety factor.When l_(v)=l_(sp),the minimum amount of protective material per unit area is required.At this time,the framework parameters that meet the requirements of safety factor,structural strength and construction structure are the optimal solutions.