埋地供水管道地震动水压力变化特性研究
发布时间：2018-07-24 21:42
【摘要】：地震动水压力作为影响埋地供水管道工作的主要水力作用之一,通过对其变化特性的研究,可以为埋地供水管道抗震设计提供建议,具有很高的理论研究价值和现实意义。本文通过对现阶段研究地震动水压力的主要方法和流固耦合理论进行总结,并结合结构动力学、流体力学、模态叠加理论、地震反应谱理论等理论方法着重引进、介绍适用于计算管道地震动水压力的计算方法,确定影响埋地供水管道地震作用下动水压力变化的因素,然后使用有限元软件ADINA对地震加载方向、管长、地震峰值加速度、管径、管壁厚、管流速度、管材、土体刚度、管道埋深以及管道弯曲等因素对埋地供水管道地震动水压力的影响规律进行了研究,并得到以下主要结论:(1)当地震荷载作用于管轴方向时,管流地震动水压力受地震加速度.影响最大,其变化最为明显;(2)管长小于100m时,随着管长的增大,管流的地震动水压力也会随之增加,满足线性增长趋势。管长为100m的最大动水压力可达0.43MPa,为市政供水管道最小设计压力值的71.67%。流固耦合法计算得出的管流动水压力最大值明显大于使用附加质量法求得的管流动水压力值,且P流固耦合/P附加质量法的值也随着管长的增大而有不同程度的增加。当管长为100m时,使用附加质量法计算出的管流动水压力值仅为考虑流体弹性情况下由流固耦合法计算出的地震动水压力的50.5%。(3)地震峰值加速度的变化对管流地震动水压力有着非常显著的影响,地震动水压力会随着PGA的增大而迅速增大,变化呈线性趋势。流固耦合法计算得出的管流动水压力最大值明显大于使用附加质量法求得的管流动水压力值,且随着PGA的增大,P_(流固耦合)与P_(附加质量法)的比值也会随之增大,当a_p =-0.56g时,使用流固耦合法计算出的最大动水压力可达附加质量法求出的动水压力的2.18倍。(4)埋地供水管道的管径小于0.8 m时,地震动水压力的最大值会随着管径的增大而减小,变化呈线性趋势。管径为0.4m时的最大地震动水压力为管径为0.8m时的最大地震动水压力的1.29倍。(5)埋地供水管道的管壁厚小于0.06m时,地震动水压力的最大值会随着管壁厚的增大而增大,变化呈线性趋势。管壁厚为0.06m时的最大地震动水压力为管径为0.02m时的最大地震动水压力的1.08倍。(6)当埋地供水管道内管流的流速方向与地震速度荷载方向相同时,管流流速会对管流的地震动水压力起到放大作用,且在一定范围内,流速对动水压力的放大效应随着流速的增大而增大。在地震速度荷载方向与管流流速方向相同且地震动水压力达到极值的典型时刻t=3.9s,地震动水压力先是随着管流速度的增加而迅速变大,管流速度为1m/s时的地震动水压力最大值是管流速度为4m/s时地震动水压力最大值的75.5%。当管流初始速度大于4m/s时,地震动水压力的增长趋势明显变缓,并最终趋于稳定。管流初始速度为6m/s时对应的地震动水压力为管流初始速度为7m/s时的地震动水压力的 99.3%。(7)当埋地供水管的管材发生改变时,地震动水压力的最大值会随着管道材料的弹性模量的增大而减小,在弹性模量较小时这种变化尤为明显,随着管材弹性模量的不断增大,地震动水压力的变化最终趋于稳定。使用混凝土管模型计算得到的地震动水压力最大值为使用PE管模型计算得到的地震动水压力最大值的94.8%,而使用钢管模型计算得到的地震动水压力最大值为使用铜管模型计算得到的地震动水压力最大值的98.6%。另外,通过对比钢管模型和高泊松比钢管模型的最大动水压力值可以看出,当管道材料的泊松比变大时,管流的动水压力也随之变大。(8)当敷设管道场地的土体刚度较小时,管流的地震动水压力会随着土体弹性模量的增大而迅速减小,随着土体弹性模量的不断增大,管流地震动水压力的减小趋势也逐渐趋于平缓,当土体的弹性模量达到44GPa时,管流的地震动水压力趋于稳定。土体弹性模量为5.7GPa时管流的动水压力最大值为土体弹性模量为44GPa时管流的地震动水压力最大值的1.16倍。(9)当埋地供水管道埋深小于2.5 m时,随着管道埋深的增加,管流的地震动水压力有小幅减小,其减小趋势基本满足线性趋势。管道埋深为2.5m时管流的最大地震动水压力值为管道埋深为0.5m时管流地震动水压力最大值的97.5%,可见管道埋深对动水压力的影响有限。(10)埋地供水管道发生弯曲时,其弯头处的地震动水压力会明显大于直管管流中相应位置的地震动水压力,埋地弯管弯头处管流的地震动水压力最大值是直管管流地震动水压力的2.19倍。
[Abstract]:Seismic dynamic water pressure is one of the main hydraulic effects that affect the work of buried water supply pipeline. Through the study of its change characteristics, it can provide suggestions for seismic design of buried water supply pipeline. It has high theoretical research value and practical significance. The main method of seismic dynamic water pressure and fluid solid coupling reasonable at the present stage is adopted in this paper. On the basis of the summary, and combining the structural dynamics, fluid mechanics, modal superposition theory, seismic response spectrum theory and other theoretical methods, it introduces the calculation method suitable for calculating the seismic dynamic water pressure of the pipeline, determines the factors affecting the change of the dynamic water pressure of the buried water supply pipeline under the earthquake action, and then uses the finite element software ADINA for the earthquake. The effects of loading direction, length of pipe, pipe diameter, pipe diameter, pipe wall thickness, pipe flow velocity, pipe material, soil stiffness, buried depth of pipe and pipe bending on the seismic dynamic water pressure of buried water supply pipeline are studied, and the following main conclusions are obtained: (1) when the seismic load acts on the axis direction of the pipe, the seismic dynamic water pressure of the pipe flow is affected. Earthquake acceleration has the greatest influence and its variation is the most obvious. (2) when the length of pipe is less than 100m, with the increase of pipe length, the seismic dynamic water pressure of pipe flow will also increase to meet the linear growth trend. The maximum dynamic water pressure of the pipe length of 100m can reach 0.43MPa, which is calculated by the 71.67%. fluid solid coupling method of the minimum design pressure value of the municipal water supply pipe. The maximum value of the flow pressure of the pipe is obviously larger than that of the pipe flow pressure used by the additional mass method, and the value of the P fluid solid coupling /P added mass method also increases with the length of the pipe. When the pipe length is 100m, the pressure value of the flow water calculated by the additional mass method is only considering the fluid structure under the fluid elastic condition. The variation of 50.5%. (3) peak acceleration of seismic dynamic water pressure calculated by coupling method has a very significant influence on the hydrodynamic pressure of the pipe flow. The dynamic water pressure will increase rapidly with the increase of PGA, and the change shows a linear trend. The maximum value of the flow pressure of the pipe flow obtained by the fluid solid coupling method is obviously larger than that of the use of the added mass. With the increase of PGA, the ratio of P_ (fluid solid coupling) and P_ (additional mass method) will increase with the increase of the flow pressure. When a_p =-0.56g, the maximum dynamic water pressure calculated by the fluid solid coupling method can reach 2.18 times that of the additional mass method. (4) the pipe diameter of the buried water supply pipe is less than 0.8 m, the earthquake is less than 0.8 m. The maximum dynamic water pressure decreases with the increase of pipe diameter, and the change shows a linear trend. The maximum seismic hydrodynamic pressure when the pipe diameter is 0.4m is 1.29 times the maximum seismic dynamic water pressure when the pipe diameter is 0.8m. (5) when the pipe wall thickness of buried water supply pipe is less than 0.06m, the maximum value of seismic dynamic water pressure will increase with the increase of pipe wall thickness. The maximum seismic dynamic water pressure when the wall thickness is 0.06m is 1.08 times that of the maximum seismic dynamic water pressure when the pipe diameter is 0.02M. (6) when the velocity direction of the pipe flow in the buried water pipe is the same as the velocity of the seismic velocity, the flow velocity of the pipe flow will amplify the seismic dynamic water pressure of the pipe flow, and in a certain range, the flow will be in a certain range. The amplification effect of the velocity on the dynamic water pressure increases with the flow velocity increasing. At the typical time of the seismic velocity load and the flow velocity of the tube, the seismic dynamic water pressure is t=3.9s, and the seismic dynamic water pressure increases rapidly with the increase of the pipe flow velocity, and the maximum value of the seismic dynamic water pressure when the pipe flow velocity is 1m/s is the pipe. When the flow velocity is 4m/s, the maximum value of seismic dynamic water pressure is 75.5%. when the initial velocity of the pipe flow is greater than 4m/s, the growth trend of the seismic dynamic water pressure is obviously slowed down, and eventually tends to be stable. The seismic dynamic water pressure corresponding to the initial velocity of the pipe flow is 99.3%. (7) of the ground vibration water pressure when the initial velocity of the pipe flow is 7m/s (7) when the buried water supply pipe is buried. When the pipe material changes, the maximum seismic dynamic water pressure decreases with the increase of the elastic modulus of the pipe material, especially in the small modulus of elastic modulus. With the continuous increase of the elastic modulus of the pipe, the change of the dynamic water pressure of the earthquake eventually tends to be stable. The seismic dynamic water pressure calculated by the concrete pipe model is made. The maximum value is 94.8% of the maximum dynamic water pressure calculated by the pipe model, and the maximum dynamic water pressure calculated by the steel pipe model is 98.6%. of the maximum dynamic water pressure calculated by the copper tube model, and the maximum dynamic water pressure value of the steel pipe model and the high Poisson ratio steel pipe model is compared. It can be seen that when the Poisson ratio of the pipe material becomes larger, the dynamic water pressure of the pipe flow becomes larger. (8) when the soil stiffness of the pipe laying site is small, the seismic dynamic water pressure of the pipe flow will decrease rapidly with the increase of the elastic modulus of the soil, and the trend of the seismic dynamic water pressure decreases with the increase of the elastic modulus of the soil. When the elastic modulus reaches 44GPa, the seismic dynamic water pressure of the pipe flow tends to be stable. When the elastic modulus of soil is 5.7GPa, the maximum dynamic water pressure of the pipe flow is 1.16 times the maximum of the seismic dynamic water pressure of the pipe flow when the soil elastic modulus is 44GPa. (9) when the buried depth of the buried water pipeline is less than 2.5 m, the pipeline buried with the pipe buried. When the depth of pipe buried is 2.5m, the maximum seismic dynamic water pressure of pipe flow is 97.5% of the maximum seismic dynamic water pressure of pipe flow when the pipeline buried depth is 0.5m. It can be seen that the effect of pipeline buried depth to the dynamic water pressure is limited. (10) the occurrence of buried water supply pipeline. When bending, the seismic dynamic water pressure at the bend at the elbow is obviously larger than the corresponding seismic dynamic water pressure in the pipe flow in the straight pipe. The maximum seismic dynamic water pressure of the pipe flow at the elbow of the buried pipe is 2.19 times that of the direct pipe flow seismic dynamic water pressure.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.36
[Abstract]:Seismic dynamic water pressure is one of the main hydraulic effects that affect the work of buried water supply pipeline. Through the study of its change characteristics, it can provide suggestions for seismic design of buried water supply pipeline. It has high theoretical research value and practical significance. The main method of seismic dynamic water pressure and fluid solid coupling reasonable at the present stage is adopted in this paper. On the basis of the summary, and combining the structural dynamics, fluid mechanics, modal superposition theory, seismic response spectrum theory and other theoretical methods, it introduces the calculation method suitable for calculating the seismic dynamic water pressure of the pipeline, determines the factors affecting the change of the dynamic water pressure of the buried water supply pipeline under the earthquake action, and then uses the finite element software ADINA for the earthquake. The effects of loading direction, length of pipe, pipe diameter, pipe diameter, pipe wall thickness, pipe flow velocity, pipe material, soil stiffness, buried depth of pipe and pipe bending on the seismic dynamic water pressure of buried water supply pipeline are studied, and the following main conclusions are obtained: (1) when the seismic load acts on the axis direction of the pipe, the seismic dynamic water pressure of the pipe flow is affected. Earthquake acceleration has the greatest influence and its variation is the most obvious. (2) when the length of pipe is less than 100m, with the increase of pipe length, the seismic dynamic water pressure of pipe flow will also increase to meet the linear growth trend. The maximum dynamic water pressure of the pipe length of 100m can reach 0.43MPa, which is calculated by the 71.67%. fluid solid coupling method of the minimum design pressure value of the municipal water supply pipe. The maximum value of the flow pressure of the pipe is obviously larger than that of the pipe flow pressure used by the additional mass method, and the value of the P fluid solid coupling /P added mass method also increases with the length of the pipe. When the pipe length is 100m, the pressure value of the flow water calculated by the additional mass method is only considering the fluid structure under the fluid elastic condition. The variation of 50.5%. (3) peak acceleration of seismic dynamic water pressure calculated by coupling method has a very significant influence on the hydrodynamic pressure of the pipe flow. The dynamic water pressure will increase rapidly with the increase of PGA, and the change shows a linear trend. The maximum value of the flow pressure of the pipe flow obtained by the fluid solid coupling method is obviously larger than that of the use of the added mass. With the increase of PGA, the ratio of P_ (fluid solid coupling) and P_ (additional mass method) will increase with the increase of the flow pressure. When a_p =-0.56g, the maximum dynamic water pressure calculated by the fluid solid coupling method can reach 2.18 times that of the additional mass method. (4) the pipe diameter of the buried water supply pipe is less than 0.8 m, the earthquake is less than 0.8 m. The maximum dynamic water pressure decreases with the increase of pipe diameter, and the change shows a linear trend. The maximum seismic hydrodynamic pressure when the pipe diameter is 0.4m is 1.29 times the maximum seismic dynamic water pressure when the pipe diameter is 0.8m. (5) when the pipe wall thickness of buried water supply pipe is less than 0.06m, the maximum value of seismic dynamic water pressure will increase with the increase of pipe wall thickness. The maximum seismic dynamic water pressure when the wall thickness is 0.06m is 1.08 times that of the maximum seismic dynamic water pressure when the pipe diameter is 0.02M. (6) when the velocity direction of the pipe flow in the buried water pipe is the same as the velocity of the seismic velocity, the flow velocity of the pipe flow will amplify the seismic dynamic water pressure of the pipe flow, and in a certain range, the flow will be in a certain range. The amplification effect of the velocity on the dynamic water pressure increases with the flow velocity increasing. At the typical time of the seismic velocity load and the flow velocity of the tube, the seismic dynamic water pressure is t=3.9s, and the seismic dynamic water pressure increases rapidly with the increase of the pipe flow velocity, and the maximum value of the seismic dynamic water pressure when the pipe flow velocity is 1m/s is the pipe. When the flow velocity is 4m/s, the maximum value of seismic dynamic water pressure is 75.5%. when the initial velocity of the pipe flow is greater than 4m/s, the growth trend of the seismic dynamic water pressure is obviously slowed down, and eventually tends to be stable. The seismic dynamic water pressure corresponding to the initial velocity of the pipe flow is 99.3%. (7) of the ground vibration water pressure when the initial velocity of the pipe flow is 7m/s (7) when the buried water supply pipe is buried. When the pipe material changes, the maximum seismic dynamic water pressure decreases with the increase of the elastic modulus of the pipe material, especially in the small modulus of elastic modulus. With the continuous increase of the elastic modulus of the pipe, the change of the dynamic water pressure of the earthquake eventually tends to be stable. The seismic dynamic water pressure calculated by the concrete pipe model is made. The maximum value is 94.8% of the maximum dynamic water pressure calculated by the pipe model, and the maximum dynamic water pressure calculated by the steel pipe model is 98.6%. of the maximum dynamic water pressure calculated by the copper tube model, and the maximum dynamic water pressure value of the steel pipe model and the high Poisson ratio steel pipe model is compared. It can be seen that when the Poisson ratio of the pipe material becomes larger, the dynamic water pressure of the pipe flow becomes larger. (8) when the soil stiffness of the pipe laying site is small, the seismic dynamic water pressure of the pipe flow will decrease rapidly with the increase of the elastic modulus of the soil, and the trend of the seismic dynamic water pressure decreases with the increase of the elastic modulus of the soil. When the elastic modulus reaches 44GPa, the seismic dynamic water pressure of the pipe flow tends to be stable. When the elastic modulus of soil is 5.7GPa, the maximum dynamic water pressure of the pipe flow is 1.16 times the maximum of the seismic dynamic water pressure of the pipe flow when the soil elastic modulus is 44GPa. (9) when the buried depth of the buried water pipeline is less than 2.5 m, the pipeline buried with the pipe buried. When the depth of pipe buried is 2.5m, the maximum seismic dynamic water pressure of pipe flow is 97.5% of the maximum seismic dynamic water pressure of pipe flow when the pipeline buried depth is 0.5m. It can be seen that the effect of pipeline buried depth to the dynamic water pressure is limited. (10) the occurrence of buried water supply pipeline. When bending, the seismic dynamic water pressure at the bend at the elbow is obviously larger than the corresponding seismic dynamic water pressure in the pipe flow in the straight pipe. The maximum seismic dynamic water pressure of the pipe flow at the elbow of the buried pipe is 2.19 times that of the direct pipe flow seismic dynamic water pressure.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.36
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