城市地下管道渗漏引起的路面塌陷机理分析与研究

发布时间：2018-07-10 16:37

本文选题：地下管道 + 渗漏　；参考：《郑州大学》2017年硕士论文

【摘要】：近年来国内外城市路面塌陷事故频发,造成了人们生命和财产的巨大损失。在所有路面塌陷事故的成因中,管道破裂渗漏所造成的影响占有较大的比重,因此对地下管道渗漏引起的路面塌陷机理进行分析与研究,对保护人们人身安全和减少财产损失具有重要意义。本文通过渗流理论、室内模型试验、数值模拟等方法对管道破损渗漏导致的路面塌陷机理及塌陷影响因素进行了研究。(1)针对管周土体两种不同的破坏形式,推导了地下水内渗破坏管周土时的临界地下水位降幅和临界地下水流速,管周土体冲蚀破坏时管道内水体的临界渗流速度。(2)推导了路面塌陷前地下空洞的临界跨径与上覆土层的厚度、土的粘聚力、内摩擦角、容重、外部荷载等之间的关系。(3)通过室内模型试验得到地下水内渗破损管道的地下空洞形态为圆锥柱形,管内水体冲蚀管周土体的地下空洞形态为椭球形。并研究了在不同的管道破损口形式和大小时,地下空洞形态的发展变化。(4)通过FLAC3D数值模拟,认为对于外渗空洞塌陷,在5m上覆土层厚度时,导致空洞塌陷的临界跨径为6m。在3m空洞跨径时,导致空洞塌陷的临界上覆土层厚度为4m。而土体的粘聚力和内摩擦角的减小导致土体强度的降低,增大了外渗地下空洞的不稳定性,当土的粘聚力为13kPa和内摩擦角为14°时,地下空洞将处于失稳状态。(5)通过FLAC3D数值模拟,认为对于内渗空洞塌陷,在5m上覆土层厚度时,导致空洞塌陷的临界跨径为4m。在4m空洞跨径时,导致空洞塌陷的临界上覆土层厚度为6m。而土体的粘聚力和内摩擦角的减小导致土体强度的降低,也增大了内渗地下空洞的不稳定性,当土的粘聚力为10kPa和内摩擦角为14°时,地下空洞将处于失稳状态。
[Abstract]:In recent years, the frequent accidents of urban pavement collapse at home and abroad have caused great loss of people's lives and property. Among all the causes of pavement collapse accidents, the influence caused by pipeline rupture and leakage occupies a large proportion, so the mechanism of pavement collapse caused by underground pipeline leakage is analyzed and studied. It is of great significance to protect people's personal safety and reduce the loss of property. In this paper, seepage theory, laboratory model test and numerical simulation are used to study the mechanism of pavement collapse caused by pipe breakage and leakage and its influencing factors. (1) two different failure forms of soil around pipe are studied. The decrease of critical groundwater level and the critical velocity of groundwater are derived. The critical seepage velocity of the water body in the pipeline is obtained when the soil around the pipe is eroded. (2) the critical span of the underground cavity before the pavement collapse and the thickness of the overlying soil layer, the cohesive force of the soil, the angle of internal friction, the bulk density, are derived. (3) through the laboratory model test, the underground cavity shape of the damaged underground water seepage pipeline is conical column shape, and the underground cavity shape of the soil around the pipe is ellipsoidal. At the same time, the development and change of underground cavities are studied with different types and sizes of damaged pipes. (4) through FLAC3D numerical simulation, it is considered that the critical span of cavities collapse is 6 m when the thickness of overlying soil is 5 m. At the span of 3m cavities, the critical overlying layer thickness of cavities collapsing is 4 m. However, the decrease of cohesive force and internal friction angle leads to the decrease of soil strength, which increases the instability of underground cavity. When the cohesive force of soil is 13 KPA and the angle of internal friction is 14 掳, the underground cavity will be unstable. (5) the numerical simulation of FLAC3D shows that the underground cavity will be unstable when the cohesive force is 13 KPA and the angle of internal friction is 14 掳. It is considered that the critical span of cavities collapse is 4 m when the thickness of overlying soil is 5 m. When the cavities span is 4 m, the critical overlying layer thickness of cavities collapsing is 6 m. The decrease of cohesive force and internal friction angle leads to the decrease of soil strength and increases the instability of underground cavity. When the cohesive force of soil is 10 KPA and the angle of internal friction is 14 掳, the underground cavity will be unstable.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU990.3;U418.6

【相似文献】