矿井疏干区岩溶塌陷的水击气爆作用研究
发布时间：2018-09-02 08:15
【摘要】：强降雨会导致岩溶空腔中水位的快速上升,地下河发育以及排泄条件良好或者工程活动导致水位快速下降,而地下水水位的上升下降都又会引起岩溶管道中水气压力的变化,野外地下水水气压力监测站时常监测到非常大的水气压力突变,因此通过室内水箱水位升降来模拟岩溶空腔水位上升下降,从而归纳出岩溶空腔内水气压力的变化规律。本文以湖南省宁乡大成桥为研究区,通过对研究区水气压力监测数据的分析,采用物理模型实验来模拟水击气爆效应并且通过water hammer建造岩溶管道数值分析模型来分析计算岩溶管道的瞬时水气压力。首先采用室内物理模型实验的方法对水击气爆作用进行研究。模型实验分为五个实验板块,分别对水位下降、水位上升、水位先上升后下降、水位先下降后上升以及出水的同时突然进水等情况进行实验模拟,每种情况下又设置不同的进出水速度来作对比分析。实验结果表明水位动量的改变都会产生水气压力突变,水气压力会在短时间内变得很大,这种现象叫气爆作用,水位下降的速度越快产生的突变压力越大。利用water hammer软件建立岩溶管道水击数值分析模型,对岩溶管道各个节点距离、管道直径,节点水头等相关参数设置,通过计算得出岩溶管道模型的初始条件参数。通过模型中的水泵的开停以及流量控制阀的初始流量等相关操作设置来模拟岩溶管道中地下水动量的改变。该模型可以计算出稳态下岩溶管道模型各个节点、管道压力值以及水流流速,同时在地下水处于非稳态时计算出发生水击的时刻,气爆或气穴的气体体积,各节点、管道的极限压力以及水流流量。
[Abstract]:Heavy rainfall will lead to the rapid rise of water level in karst cavities, the development and discharge conditions of underground rivers or engineering activities will lead to a rapid decline of water level, and the rise and fall of groundwater level will cause changes of water pressure in karst pipelines. In the field groundwater gas pressure monitoring station often detects very big water gas pressure abrupt change, therefore through the indoor water tank water level rise and fall to simulate the karst cavity water level to rise and fall, thus induces the karst cavity water gas pressure change rule. This paper takes Dacheng Bridge, Ningxiang, Hunan Province as the research area, and analyzes the monitoring data of water and air pressure in the study area. The physical model experiment is used to simulate the gas burst effect of water hammer and the numerical analysis model of karst pipeline constructed by water hammer is used to analyze and calculate the instantaneous water gas pressure of karst pipeline. Firstly, the air burst of water hammer is studied by using the method of indoor physical model experiment. The model experiment is divided into five experimental plates, respectively, the water level falls, the water level rises, the water level rises first, then the water level rises, and the water level drops first and then rises, and the effluent suddenly enters the water at the same time. In each case, different inlet and outlet speeds are set for comparative analysis. The experimental results show that the change of water level momentum will produce a sudden change of water vapor pressure, which will become very large in a short period of time. This phenomenon is called gas explosion, and the faster the water level drops, the greater the sudden pressure will be. The numerical analysis model of karst pipeline water hammer is established by using water hammer software. The parameters such as the distance of each node, the diameter of the pipe and the head of the node are set up, and the initial parameters of the karst pipeline model are obtained by calculation. The change of groundwater momentum in karst pipeline is simulated by the operation settings of pump opening and stopping in the model and the initial flow rate of flow control valve. The model can calculate the node, pipeline pressure value and flow velocity of karst pipeline model under steady state. At the same time, the gas volume of gas burst or cavitation, each node can be calculated when the groundwater is in unsteady state. The limit pressure and flow rate of the pipeline.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD74
，
本文编号：2218785
[Abstract]:Heavy rainfall will lead to the rapid rise of water level in karst cavities, the development and discharge conditions of underground rivers or engineering activities will lead to a rapid decline of water level, and the rise and fall of groundwater level will cause changes of water pressure in karst pipelines. In the field groundwater gas pressure monitoring station often detects very big water gas pressure abrupt change, therefore through the indoor water tank water level rise and fall to simulate the karst cavity water level to rise and fall, thus induces the karst cavity water gas pressure change rule. This paper takes Dacheng Bridge, Ningxiang, Hunan Province as the research area, and analyzes the monitoring data of water and air pressure in the study area. The physical model experiment is used to simulate the gas burst effect of water hammer and the numerical analysis model of karst pipeline constructed by water hammer is used to analyze and calculate the instantaneous water gas pressure of karst pipeline. Firstly, the air burst of water hammer is studied by using the method of indoor physical model experiment. The model experiment is divided into five experimental plates, respectively, the water level falls, the water level rises, the water level rises first, then the water level rises, and the water level drops first and then rises, and the effluent suddenly enters the water at the same time. In each case, different inlet and outlet speeds are set for comparative analysis. The experimental results show that the change of water level momentum will produce a sudden change of water vapor pressure, which will become very large in a short period of time. This phenomenon is called gas explosion, and the faster the water level drops, the greater the sudden pressure will be. The numerical analysis model of karst pipeline water hammer is established by using water hammer software. The parameters such as the distance of each node, the diameter of the pipe and the head of the node are set up, and the initial parameters of the karst pipeline model are obtained by calculation. The change of groundwater momentum in karst pipeline is simulated by the operation settings of pump opening and stopping in the model and the initial flow rate of flow control valve. The model can calculate the node, pipeline pressure value and flow velocity of karst pipeline model under steady state. At the same time, the gas volume of gas burst or cavitation, each node can be calculated when the groundwater is in unsteady state. The limit pressure and flow rate of the pipeline.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD74
，
本文编号：2218785
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