DISTRIBUTION LAW OF CRUSTAL STRESS IN DIFFERENT COMBINA-TIONS OF IMBRICATE REVERSE FAULTS

Imbricate reverse fault is a kind of fault combination in crust. This paper aims to reveal the crustal stress distributed between imbricate reverse faults under different combinations. It takes Longmenshan fault as research background. The large physical simulation tests are carried out. Crustal stress distributing and changing laws are got as follows.(1) There are two parallel imbricate reverse fault distributions in research area. Their trends are penperdicular to tectonic compression direction. The fault near the compressing part can fail firstly. Meanwhile, it can result in stress release. However, there can be a sudden stress increasing around underlying fault in depth.(2) There are not only two parallel imbricate reverse faults, but also, a thrust fault distributed between them. The tectonic compression direction is perpendicular to imbricate reverse fault. The shallow crustal stress changes early. Crust may break along imbricate thrust fault.(3) There are not only imbricate reverse fault, but also another thrust fault distributed between them. The tectonic compression direction and strike of imbricate thrust fault are skew. The crust may break along thrust fault which distributes between imbricate thrust faults.(4) When there are only imbricate thrust faults, the crustal stress distributes uniformly. However, stress concentration phenomenon appears at the end or intersection of several faults. The research has certain guiding significance to regional stability evaluation and earthquake prediction.