降雨对缓坡抗浮水位的影响及基底浮力的计算

发布时间：2018-05-06 23:21

本文选题：缓坡 + 降雨入渗　；参考：《昆明理工大学》2017年硕士论文

【摘要】：随着城镇化的推进,为了避免占用大片优质耕地,许多建筑开始向一定坡度的缓坡地带发展;在城镇化推进的过程中,大量的高层建筑开始兴建,为满足人防工程、地下车库及相关设施的要求,都包含地下室部分,在设计地下室基础时,必须要考虑到地下室抗浮水位的设计。在现有的抗浮水位设计中大多依靠多年的地下水位监测资料或对场地整个区域的地质条件的熟悉,但这恰恰是许多单位所缺乏的。如何依靠现有的气象资料和勘察设计资料确定抗浮水位成为一个迫切需要解决的问题。本文针对这一问题选取某一坡地,分析影响该场地地下水位的影响因素和场地区域地质条件,采用Geo-Studio有限元计算软件分析不同降雨条件下缓坡坡体内渗流场的变化及降雨与地下水的补给关系;然后分析了同一降雨条件下不同坡度缓坡内渗流场的变化,最后在确定抗浮水位的情况下,计算缓坡地带地下室底板的地下水渗流情况。具体的研究工作如下:1.分析缓坡所处区域的地质特点、地下水的赋存形式及来源,确定了影响该区域地下水的主要因素是降雨;2.运用Geo-Studio二维有限元软件分析了不同降雨条件下缓坡内渗流场的变化及其地下水位线的变化,并分析了在降雨过程中随着降雨量、降雨强度、降雨时长的变化,坡面坡体内体积含水率和孔隙水压力的变化,研究了入渗雨水的运移规律。分析计算结果得出:降雨强度越大,容易在坡面形成径流,对坡面垂直深度影响较小,引起坡脚处地下水位上升的高度较小;降雨强度越小,降雨时间较长,雨水容易入渗坡体,入渗深度也越大,引起地下水位上升也较高;3.分析了在相同的降雨强度条件下不同坡度缓坡地下水位线的变化,计算结果表明:坡度越大,雨水越不易在坡面停留,对坡面的纵向影响深度越小,坡脚处地下水位线高度越低;4.利用确定的缓坡抗浮水位,计算了地下室在该水位并存在水头差的情况下,底板孔隙水压力的大小,并与采用改进阻力系数法公式计算结果对比,结果表明计算误差较小,该公式可用于计算该种情形下地下室底板的浮力大小。
[Abstract]:With the promotion of urbanization, in order to avoid large area of high quality arable land, many buildings have begun to develop to a certain slope. In the process of urbanization, a large number of high rise buildings have begun to build. In order to meet the civil air defense project, the requirements of underground garage and related facilities include the basement part. When the basement is designed, it is necessary. It is necessary to take into account the design of the anti floating water level in the basement. Most of the existing anti floating water level designs depend on the monitoring data of the groundwater level for many years or the geological conditions of the whole area, but this is precisely the lack of many units. In this paper, this paper selects a slope to analyze the influence factors of the ground water level and the regional geological conditions of the site. The Geo-Studio finite element software is used to analyze the changes in the seepage flow in the gentle slope of the slope under different rainfall conditions and the relationship between the rainfall and the recharge of the groundwater; then the same is analyzed. Under the condition of rainfall, the seepage flow field of different slope gentle slope is changed. Finally, under the condition of determining the anti floating water level, the groundwater seepage in the basement floor of the gentle slope zone is calculated. The specific research work is as follows: 1. the geological characteristics of the region where the gentle slope is located, the form and source of the groundwater are determined, and the main factors affecting the groundwater in this area are determined. The factor is rainfall; 2. the changes in the internal seepage flow field and the change of the groundwater level line in the gentle slope under different rainfall conditions are analyzed by the Geo-Studio two dimensional finite element software, and the changes of the rainfall, rainfall intensity and the length of the rainfall in the process of rainfall are analyzed, and the changes in the volume of volume of water and pore water pressure in the slope of the slope are studied. The calculation results show that the larger the rainfall intensity, the runoff is easy to be formed on the slope, the lower the vertical depth of the slope, the smaller the elevation of the groundwater level at the foot of the slope, the smaller the rainfall intensity, the longer rainfall time, the easy infiltration of the slope, the greater the infiltration depth, and the higher groundwater level. 3. the change of water level line of different slope gentle slope under the same rainfall intensity is analyzed. The calculation results show that the greater the slope, the less easy the rain is to stay on the slope, the smaller the longitudinal influence depth of the slope is, the lower the height of the groundwater level line at the foot of the slope; and 4. to calculate the existence of the basement at the water level by using the determined gentle slope anti floating water level. In the case of poor water head, the size of the pore water pressure of the floor is compared with the calculated result by the formula of the improved resistance coefficient method. The result shows that the calculation error is small, and the formula can be used to calculate the buoyancy size of the basement floor in this case.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU463;TU943.1

【参考文献】