地面沉降主要有(1)由过量开采地下水引起的和(2)在新构造活动构造沉降的基础上,由开采地下水、油气、地下热水形成的地面沉降两种类型.不仅不同的土层有不同的变形特点,在不同地点的同一土层也有不同的变形特点.同一地点同一土层在不同时期的变形特点也不尽相同.建立数学模型时要根据土层实际变形特点分别建立相应的模型,才能模拟出真实的地面沉降情况.解决耦合问题和垂向、水平向尺度不同带来的困难也是正确模拟必不可少的.
The land subsidence in China can be divided into two types: ( 1 ) the subsidence mainly caused by excessive groundwater withdrawal; (2) the subsidence caused by groundwater, oil, gas and warm groundwater withdrawal, and superposing on the neotectonic movement. Not only the different layers have different deformation features, but also the same layers in different locations have different deformation features. Even in the same location the same layers have different features in different stage. The corresponding models based on the actual deformation features of the soil should be built in order to simulate the real subsidence condition. The coupling of the models and the difference between vertical and horizontal scales are the problems to be solved for the accurate simulation.