西安地面沉降及地裂缝阶段预测

DEVELOPING STAGE FORECAST OF LAND SUBSIDENCE AND GROUND FISSURE, XI'AN

地面沉降及地裂缝可视其为复合地质灾害现象。二者性质不同,但就其发展阶段或单旋回过程而言,皆可将其归并于有限系统。本文讨论了西安市小寨地面沉降带的地质背景,建立了泊松旋回预测方程,论证了二者的演化规律及其盛衰阶段。引入指数函数法,进行了沉降阶段的对比研究。根据历史记录,讨论了西安地裂缝兴衰与我国陆块板内地震活动的对应关系。

<ABSTRACT> Land subsidence and ground fissure are considered to be a complicated hazard phenomena. They show different characteristics, nevertheless they may be merged into a limited system with finite life-span. As a typical example the land subsidence and ground fissure of Xiaozhai, Xi'an are cited. In this paper the geological background is discussed. By Poissin cycle fundamentals the principle of forecasting equation establishment is empha- sized aiming at the objective function to fit the criterion of minimum absolute deflection with optimizing conditions. Stage forecast for both of them is generally performed. Accor- ding to exponent function method the comparision study with that of Poisson cycle is car- ried out. Specially the developing stage and the substantiality of ground fissure in Xi'an are emphatically dischssed. It is concluded that the origin of subsiding velocity of Xi'an being higher than that both of Shanghai and Tianjin is resulted by superposition of other relative velocity compo- nent on its two sides of the ground fissure which shows surface deformation caused by geo-stress adjustment of underground fault system with activity hinting a coming strong earthquake of other locality.