植被混凝土新型生境构筑基材稳定性分析

Stability analysis on base material for building of new type of vegetation-growing concrete habitat

利用植被混凝土生态技术修复的边坡,其失稳破坏问题仍然存在,利用不同破坏模式下的剪切应力—位移曲线,在确定滑面上进行受力分析,考虑降雨对基材重度、冲刷作用及剪切应力折减的影响,确定了基材安全系数与位移变化关系,对新型基材构筑方式进行稳定性分析,对口型坑贡献率进行评价。结果表明:新型构筑方式能有效增大各工况下基材破坏位移,天然状态下为喷播基材的1.25~1.46倍,降雨时为喷播基材的1.14~1.25倍。施工后,随着根土复合体逐渐形成,两种构筑方式下的安全系数可增加为原来的1.53~1.6倍。安全系数随着口型坑尺寸增大,基材破坏位移、贡献率逐渐增加。算例表明,口型坑最大贡献率能达到88.52%。

So far as the slope restored with the eco-technology of vegetation-growing concrete is concerned,the problem of instability failure is still there,for which a stress analysis is made herein on the defined sliding-plane with the the shear stress-displacement curves under various failure modes. The relationship between the safety coefficient of the base material and the displacement variation is determined under the consideration of the influence from rainfall on the unit weight of base material,scouring effect and shear stress reduction,and then a stability analysis is made on the building mode of the new type of base material,while the contribution rate of the mouth-shaped pit is evaluated as well. The result shows that the new type of building mode can effectively increase the base material failure displacements under all the working conditions,which are 1. 25 ~ 1. 46 times of those from the spray-seeding base material under the natural status and 1. 14 ~ 1. 25 times of those from the spray-seeding base material during rainfall. After construction,the safety coefficients under both the construction modes can be increased to 1. 53 ~1. 6 times of the original ones along with the gradual formation of the root-soil composite body. The safety coefficient is gradually increased along with the increase of the size of the mouth-shaped pit,the base material failure displacement and the gradual increase of the contribution rate. The relevant calculation case shows that the maximum contribution rate of the mouth-shaped pit can reach to 88. 52%.