山西地堑系地裂缝发育及其与水土流失的关系

Development of Ground Fissures and Soil Erosion in the Shanxi Graben System

研究了山西地堑系地裂缝的平面分布、剖面特征及其与断层、地下水变化和暴雨过程的关系,并讨论了地裂缝发育与水土流失的关系。山西地堑系的地裂缝有很强的方向性,与区域构造线走向一致,许多地裂缝向下与活动断层相通,它们的形成与构造运动有密切的关系。一些地裂缝的发育与暴雨过程密切相关,这些地裂缝主要发育在黄土地层中,它们的形成与黄土易于发生潜蚀有关。黄土潜蚀形成的地裂缝的发育过程是山西地堑系一种普遍存在、危害严重的水土流失的方式。

Since 1950s,hundreds of ground fissures have occurred in the Shanxi Graben System in the northeast China.The fissures ,and related subsidence and differential settlement have caused and are causing substantial damage to homes ,agricultural land,roads,canals,and other infrastructures.Although generally similar in appearance,the fissures have different origins.Some coincide with northeast trending faults.Trenching shows that the fissures extend into the near surface faults,increasingly vertically offset clay beds and other stratigraphic markers at depth,and therefore are probably the surface expressions of aseismic fault movements.Some fissures are demonstrably related to accelerated groundwater withdrawal.This is particularly apparent in Datong and Yuci where groundwater levels have declined greatly.Other fissures owe their origin to the well known process of “soil collapse.”This is particularly common in the silty loessial sediments that occur within most of the basins that comprise theha Shanxi Graben System.The“soil collapse”along the ground fissures is a popular way of soil erosion in the Shanxi Graben System.