推覆构造滑脱层有限变形力学分析

MECHANICAL ANALYSIS OF FINITE DEFORMATION OF DECOLLEMENT LEVEL IN NAPPE STRUCTURE

本文根据推覆构造滑脱层的变形特点,运用以S—R分解定理为基础的有限变形力学理论,研究了断坪与断坡滑脱层的变形场特征。用全量及增量方法逆解求出了变形滑脱层所受的边界外力;利用变形场与应力场的分析结果,给出了推覆构造在拆离时推覆席体的推移距离及作用推力的简捷计算公式。

In accordance with the deformational features of decollement level in nappe structure and by use of the finite deformation theory of mechanics based on the S--R decomposition theorem, the characteristics of deforming field of the decollement level, both at the flat and the ramp, are studied in this paper. Correspond to the approach, the forces applied on the boundaries of the defoming decollement level are achieved using the total and incrimental inverse solutions. On the bases of the analytical results of deformation and stress fields, some concise formulae to calculate the thrust distance of the overlying thrust sheet and the force existing on the trailing edge of the sheet while decoupling are given.