地层的固结特性与地面沉降临界水位控沉

Characteristics of Strata Consolidation and Land Subsidence Controlling by Critical Water Level

在地质历史上，天津市沉积了巨厚的第四纪松散地层及第三纪松散、半胶结的地层。并赋存了地下水资源，地热及油气资源。这些资源的开发为人类的进步和发展做出发了巨大贡献，同时也引起了严重的地面沉降。第四系大致可分为５个承压含水层组及１１个工程地质层。物质经过搬运、沉积后，在各种自然因素的作用下，地层逐渐固结压密。地层在历史上承受过的最大垂直有效应力称为地层的前期固结压为Ｐｃ。根据Ｐｃ与Ｐｏ（自重应力）的相对大小，可将地层分为欠固结、正常固结及超固结。松散沉积层的固结状态与地面沉降关系极为密切。实践证明，超固结地层中地下水临界水位值是客观存在的，并可用实验资料确定其临界水位值，在控制地面沉降中具有重要的现实意义。

In the geological history, vast thick loose Quaternary strata and semicemented Tertiary strata were formed in Tianjin Groundwater resources, geothermal resource and oilgas resources exist in the strata The serious land subsidence has been induced by exploiting these resources During transportation and sedimentation, the sediments in the strata were consolidated and compacted under the influence of various natural factors The various state of consolidation has close relations with the land subsidenceThe state of consolidation can be judged by the ration between the consolidation pressure of earlier stage (pc)and the stress of selfweight(Po) Practice shows that the objective reality is a critical water level in the overconsolidated strata which can be defined by test data The critical water level can play an important and practical role in controlling the land subsidence