The lateral seal and vertical seal mechanism of fault and effecting factor are analyzed, the result shows that the evaluation method of fault lateral seal is Allan that is the base, using shale content calculation result to forecast fault rock type, the evaluation method of fault vertical seal is to calculate fault plane normal pressure and analyze fracture seal.

Analysis on fault s vertical sealing and its evolution by normal pressure of fault surface method in the Weixinan Sag,Beibu Gulf Basin;

The time-space distribution of vertical seal in Shurennouer Fault was analyzed,according to the fault plane pressure and mudstone content of fault zone.

This paper describes the acquisition of various parameters in relation to frontal pressure,relationship between them and analysis or refinement of them by means of data acquisition of daily advance process performed by an upperbound shield for Changjiang Tunnel in Shanghai.

Based on the analysis of vertical seal mechanism of fault and its influence factors,by comparatively studying the pressure on fault surface and the minimum depth required in forming vertical seal of fault if there is or not overpressure in a stratum,it was considered that if there is overpressure in a stratum,the pressure on fault surface increases and the vertical seal increases.

Based on the analysis of the vertical sealing mechanism of fault and its influncing factors, this paper puts forward the conception of favounable depth forming the vertical sealing of fault, establishes the method determining upper and lower limit depth by the equalization of the vertical pressure of faulted zone to elastic limit and intensive limit of mudstone.