地面沉降预测及其风险防控对策——以大西安西咸新区为例

Prediction of land subsidence and Its mitigation methods——a case study in the new urban district of Xi'an-Xianyang

西咸新区是"西咸一体化大西安"建设的重要组成部分,与大西安已建成区具有相近的地质环境条件,西咸新区建设是否同样会引起地面沉降和地裂缝已成为西咸新区规划和建设中面临的一大难题。在分析西咸新区建设中可能引起地面沉降和地裂缝五个因素的基础上,建立了地下水开采、城市建设附加荷载和黄土湿陷引起的地面沉降预测数学模型,并分别进行了预测计算。计算结果表明,引起地面沉降的因素中地下水开采的风险最大,黄土湿陷次之,附加荷载最小,西咸新区的建设和发展中如不周密规划,有效防控,势必引起新的地面沉降,甚至产生新的地裂缝,控制地下水位是防止地面沉降与地裂缝产生的根本措施。

The new urban district of Xi'an-Xianyang is an important part for the integration of Xi'an city and Xianyang city. With the similar geological background of the developed Xi'an city,will its instruction generate ground subsidence and fissures have been a big challenge. On the basis of analyzing five factors affecting land subsidence,a numerical model was set up considering factors of groundwater exploitation,ground load,land subsidence induced by loess collapse. The results show that among the triggering factors of land subsidence,groundwater exploitation is the principle cause,loess collapse is the next,and ground load is the last. Without considerate plan and effective mitigation methods during the construction,land subsidence and fissure will probably occur. Groundwater level control is the root measure for mitigating land subsidence and fissure.