基于矢量和–非连续变形分析的滑坡安全系数计算方法研究

RESEARCH ON SAFETY FACTOR COMPUTATION OF LANDSLIDE BASED ON VECTOR SUM-DISCONTINUOUS DEFORMATION ANALYSIS METHOD

非连续变形分析(DDA)是一种满足平衡方程收敛、不连续接触的开闭迭代收敛和静力计算中的最大容许位移收敛的极限平衡计算新方法。尝试将二维矢量和法引入DDA中,并结合DDA动力迭代和接触力计算的具体特点,提出适合DDA的滑动方向与安全系数的计算方法;在此基础上,以滑动面为直线型和圆弧型的滑坡为例,通过对比理论解或刚体极限平衡解,证明基于矢量和–DDA方法计算滑坡安全系数的正确性。矢量和–DDA方法不仅基于滑坡真实的应力场计算安全系数,而且其沿滑动面对下滑力与抗滑力的积分力学意义明确,反映了"滑动"的矢量内涵。

Discontinuous deformation analysis（DDA） is a new limit equilibrium computation method,which has satisfied three convergences including convergence of equilibrium equations,convergence of open-close iterations for all contacts and convergence of the maximum displacement for static computations. The two-dimensional vector sum analysis method had been introduced in DDA,and the Vector SUM-DDA method was proposed. Considering the dynamic iterations and contact force computation in DDA,the method of slide direction and safety factor were detailed. Several numerical examples of the landslide,including a planar sliding face and a rounded sliding face,computed by Vector SUM-DDA method. Comparing to the solutions of the theoretical analysis and the limit equilibrium analysis,results show that the new method is reasonable to calculate the safety factor of landslide. The Vector SUM-DDA method calculates the safety factor based on true stress field and the integrations of slide or resistant force has reflected the concept of sliding vector.