海绵城市建设中地层特性与蓄排水功能的相互关系研究

发布时间：2018-02-23 23:11

本文关键词： 海绵城市物理力学参数软土层固结水平位移敏感性因素分析　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：海绵城市建设是解决城市开发中雨水与地表水资源综合利用、城市排水防洪和生态环境保护等问题,实现低影响开发的重要途径,对解决城市缺水和内涝等环境问题,实现城市可持续发展,具有重要意义。我国已启动海绵城市示范工程的建设,在海绵城市建设中,不同区域的城市,地形地貌、工程地质、水文地质、地表水和气象条件不同,海绵城市建设的侧重点应不同。北京市属于缺水+内涝型,但以缺水为主的城市,本文以北京市中心区海绵城市建设为背景,对土层物理力学参数对地层蓄排水的影响机理开展研究,提出了在尽可能利用自然资源的同时大量改造硬质路面让雨水能够渗入到地层中和建设回灌井把雨水导入含水层的海绵城市建设方式,按照利用地层对雨水进行收集和储存的建设方式,深入分析和揭示了土层物理力学参数对地层排水和蓄水的影响机理。主要工作及结论如下：(1)通过对北京市中心区域人口分布及土地价值、气象条件、地质条件、雨水水质等方面的评价,参考现有雨水利用方式,结合中心区域的实际情况,提出了北京市中心区域海绵城市建设方式：在尽可能利用树木、湿地、河流湖泊的情况下,重点进行人行步道、公园、停车场等地的硬质路面改造让雨水能够渗入到地层中和建设回灌井把雨水导入含水层中的海绵城市建设方式,利用天然地层对雨水进行储蓄,减少了海绵城市配套设施的建设。(2)建立了建筑荷载作用下含水层水位下降引起的软土层固结解析表达式,根据固结解析解对相关影响参数变化下的软土层固结性状进行了分析,揭示了相关物理力学参数对软土层固结沉降的影响机理,为地层排水的阈值计算提供理论依据。(3)推导了雨水入渗时地表土层的水平位移速度公式和位移量计算公式；获得了雨水回灌时含水层骨架颗粒的水平位移速度公式和位移量计算公式,揭示了相关物理力学参数对土体水平位移的影响机理,为地层蓄水的阈值计算提供理论依据。(4)基于灰色关联分析方法对影响地层排水和蓄水的相关土层参数进行敏感性因素分析,并对相关影响参数进行权重排序,确定了硬质路面改造和回灌井建设时需要重点分析的土层物理力学参数。对灰色关联分析法中的分辨系数提出了新的取值方法,并通过两个算例验证该取值方法的合理性及正确性。(5)采用FLAC3D软件模拟地层排水和蓄水的物理力学发生过程,通过模拟结果对地层排水和蓄水的发生过程进行分析和评价,得到了地层在排水和蓄水时的变化规律,验证了地层排水和蓄水理论分析和计算结果的正确性。
[Abstract]:Sponge city construction is an important way to solve the problems of Rain Water and surface water resources comprehensive utilization, urban drainage flood control and ecological environment protection in urban development, and to solve the environmental problems such as water shortage and waterlogging. It is of great significance to realize the sustainable development of the city. In the construction of the sponge city demonstration project in China, the cities, landforms, engineering geology, hydrogeology, surface water and meteorological conditions of different regions are different. The emphasis of sponge city construction should be different. Beijing belongs to the waterlogging type of water shortage, but the main city is lack of water. This paper takes the construction of sponge city in the central district of Beijing as the background. The influence mechanism of physical and mechanical parameters of soil layer on formation storage and drainage is studied. Put forward a sponge city construction mode in which Rain Water can infiltrate into the formation and build a recharge well to introduce Rain Water into the aquifer while making use of natural resources as much as possible while making a large number of hard roads. According to the construction method of collecting and storing Rain Water by using strata, The influence mechanism of physical and mechanical parameters of soil layer on drainage and water storage is analyzed and revealed in depth. The main work and conclusions are as follows: (1) through the analysis of population distribution, land value, meteorological conditions and geological conditions in the central region of Beijing, Based on Rain Water's evaluation of water quality, referring to the current mode of use of Rain Water and combining with the actual situation in the central region, this paper puts forward the construction mode of sponge city in the central region of Beijing: under the condition of making use of trees, wetlands, rivers and lakes as far as possible, Emphasis is placed on the reconstruction of hard pavement in pedestrian walkways, parks, parking lots and other places so that Rain Water can infiltrate into the formation and build a recharge well to introduce Rain Water into the aquifer for the construction of a sponge city, and use the natural strata to save Rain Water. By reducing the construction of supporting facilities in sponge city, the analytical expression of soft soil consolidation caused by the lowering of aquifer water level under building load is established, and the consolidation behavior of soft soil under the change of relevant parameters is analyzed according to the analytical solution of consolidation. The influence mechanism of relevant physical and mechanical parameters on the consolidation and settlement of soft soil is revealed, which provides a theoretical basis for the calculation of the threshold value of stratum drainage.) the formula of horizontal displacement velocity and displacement calculation of surface soil layer under Rain Water infiltration are derived. The horizontal displacement velocity formula and displacement calculation formula of aquifer skeleton particles during Rain Water recharge are obtained, and the influence mechanism of relevant physical and mechanical parameters on horizontal displacement of soil is revealed. This paper provides a theoretical basis for the threshold calculation of formation water storage. (4) based on the grey correlation analysis method, the sensitivity factors of the related soil layer parameters affecting the formation drainage and water storage are analyzed, and the weights of the relevant parameters are ranked. The physical and mechanical parameters of soil layer which need to be analyzed in the reconstruction of hard pavement and the construction of recharge wells are determined. A new method for determining the resolution coefficient in grey correlation analysis is proposed. The rationality and correctness of the method are verified by two numerical examples. The FLAC3D software is used to simulate the physical and mechanical process of formation drainage and water storage, and the process of formation drainage and water storage is analyzed and evaluated by simulation results. The variation law of formation drainage and water storage is obtained, and the correctness of theoretical analysis and calculation results of formation drainage and water storage is verified.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TU992

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