土体工程地质层划分及其在城市地下空间开发中的应用

Geological Stratification of Soil Engineering and Its Applications to Urban Underground Space Development

城市地下空间包括岩土体本身的密实部分以及天然或人工形成的无岩土体的空间部分,既是重要的自然资源,又是其它地下自然资源的载体。随着城市的不断发展,地下空间构建立体城市已成为必然选择。城市地下空间开发多在土体中进行,地下工程建设的成本、难度与土体质量息息相关。针对常州市土体工程地质层划分标准不统一的现状,基于城市地质调查项目获取的海量地质钻孔和土体物理力学指标测试结果,综合考虑沉积时代、物质成分、工程特性指标等因素,采用剖面绘制法对常州市100m以浅土体工程地质层进行划分,建立基本地层结构和层序编码,通过工程地质层物理力学参数离散性和三维模型平滑度验证划分结果合理可行。将土体工程地质层划分结果应用到桩基持力层选择、地下空间竖向分层规划、地下空间开发适宜性评价、多种地下资源协同利用等方面,可为城市地下空间规划、建设、管理提供基础数据和相关借鉴。

Urban underground space includes the compact part of soil mass and space of natural or artificial rock-free mass.It is not only an important kind of natural resource,but also a carrier of other underground natural resources.With the continuous development of cities,it is essential to build stereoscopic cities in underground spaces.Since most urban underground space development projects are implemented in soil mass,the cost and challenges of underground engineering construction are closely related with soil mass quality.At present,there are different geological stratification standards of soil engineering in Changzhou.Hence,profiling method was applied for geological stratification of soil engineering(at a depth≤100 m)in Changzhou based on mass geological drilling and soil physical and mechanical testing results from urban geological surveys.Besides,comprehensive considerations were given to sedimentation age,material composition and engineering characteristic indexes.The basic stratigraphic structure and layer numbers were established.The geological stratification results were proved reasonable and feasible by discrete performances of physical and mechanical parameters of engineering geological layers as well as the three-dimensional model smoothness.The geological stratification results of soil engineering were applied to various aspects,such as selection of pile bearing stratum,vertical stratification planning of underground space,suitability evaluation of underground space development,collaborative use of several underground resource types.The results can provide basic data and relevant references to the planning,construction and management of urban underground space.