【摘要】：地震動水壓力作為影響埋地供水管道工作的主要水力作用之一,通過對其變化特性的研究,可以為埋地供水管道抗震設(shè)計提供建議,具有很高的理論研究價值和現(xiàn)實意義。本文通過對現(xiàn)階段研究地震動水壓力的主要方法和流固耦合理論進行總結(jié),并結(jié)合結(jié)構(gòu)動力學、流體力學、模態(tài)疊加理論、地震反應(yīng)譜理論等理論方法著重引進、介紹適用于計算管道地震動水壓力的計算方法,確定影響埋地供水管道地震作用下動水壓力變化的因素,然后使用有限元軟件ADINA對地震加載方向、管長、地震峰值加速度、管徑、管壁厚、管流速度、管材、土體剛度、管道埋深以及管道彎曲等因素對埋地供水管道地震動水壓力的影響規(guī)律進行了研究,并得到以下主要結(jié)論:(1)當?shù)卣鸷奢d作用于管軸方向時,管流地震動水壓力受地震加速度.影響最大,其變化最為明顯;(2)管長小于100m時,隨著管長的增大,管流的地震動水壓力也會隨之增加,滿足線性增長趨勢。管長為100m的最大動水壓力可達0.43MPa,為市政供水管道最小設(shè)計壓力值的71.67%。流固耦合法計算得出的管流動水壓力最大值明顯大于使用附加質(zhì)量法求得的管流動水壓力值,且P流固耦合/P附加質(zhì)量法的值也隨著管長的增大而有不同程度的增加。當管長為100m時,使用附加質(zhì)量法計算出的管流動水壓力值僅為考慮流體彈性情況下由流固耦合法計算出的地震動水壓力的50.5%。(3)地震峰值加速度的變化對管流地震動水壓力有著非常顯著的影響,地震動水壓力會隨著PGA的增大而迅速增大,變化呈線性趨勢。流固耦合法計算得出的管流動水壓力最大值明顯大于使用附加質(zhì)量法求得的管流動水壓力值,且隨著PGA的增大,P_(流固耦合)與P_(附加質(zhì)量法)的比值也會隨之增大,當a_p =-0.56g時,使用流固耦合法計算出的最大動水壓力可達附加質(zhì)量法求出的動水壓力的2.18倍。(4)埋地供水管道的管徑小于0.8 m時,地震動水壓力的最大值會隨著管徑的增大而減小,變化呈線性趨勢。管徑為0.4m時的最大地震動水壓力為管徑為0.8m時的最大地震動水壓力的1.29倍。(5)埋地供水管道的管壁厚小于0.06m時,地震動水壓力的最大值會隨著管壁厚的增大而增大,變化呈線性趨勢。管壁厚為0.06m時的最大地震動水壓力為管徑為0.02m時的最大地震動水壓力的1.08倍。(6)當埋地供水管道內(nèi)管流的流速方向與地震速度荷載方向相同時,管流流速會對管流的地震動水壓力起到放大作用,且在一定范圍內(nèi),流速對動水壓力的放大效應(yīng)隨著流速的增大而增大。在地震速度荷載方向與管流流速方向相同且地震動水壓力達到極值的典型時刻t=3.9s,地震動水壓力先是隨著管流速度的增加而迅速變大,管流速度為1m/s時的地震動水壓力最大值是管流速度為4m/s時地震動水壓力最大值的75.5%。當管流初始速度大于4m/s時,地震動水壓力的增長趨勢明顯變緩,并最終趨于穩(wěn)定。管流初始速度為6m/s時對應(yīng)的地震動水壓力為管流初始速度為7m/s時的地震動水壓力的 99.3%。(7)當埋地供水管的管材發(fā)生改變時,地震動水壓力的最大值會隨著管道材料的彈性模量的增大而減小,在彈性模量較小時這種變化尤為明顯,隨著管材彈性模量的不斷增大,地震動水壓力的變化最終趨于穩(wěn)定。使用混凝土管模型計算得到的地震動水壓力最大值為使用PE管模型計算得到的地震動水壓力最大值的94.8%,而使用鋼管模型計算得到的地震動水壓力最大值為使用銅管模型計算得到的地震動水壓力最大值的98.6%。另外,通過對比鋼管模型和高泊松比鋼管模型的最大動水壓力值可以看出,當管道材料的泊松比變大時,管流的動水壓力也隨之變大。(8)當敷設(shè)管道場地的土體剛度較小時,管流的地震動水壓力會隨著土體彈性模量的增大而迅速減小,隨著土體彈性模量的不斷增大,管流地震動水壓力的減小趨勢也逐漸趨于平緩,當土體的彈性模量達到44GPa時,管流的地震動水壓力趨于穩(wěn)定。土體彈性模量為5.7GPa時管流的動水壓力最大值為土體彈性模量為44GPa時管流的地震動水壓力最大值的1.16倍。(9)當埋地供水管道埋深小于2.5 m時,隨著管道埋深的增加,管流的地震動水壓力有小幅減小,其減小趨勢基本滿足線性趨勢。管道埋深為2.5m時管流的最大地震動水壓力值為管道埋深為0.5m時管流地震動水壓力最大值的97.5%,可見管道埋深對動水壓力的影響有限。(10)埋地供水管道發(fā)生彎曲時,其彎頭處的地震動水壓力會明顯大于直管管流中相應(yīng)位置的地震動水壓力,埋地彎管彎頭處管流的地震動水壓力最大值是直管管流地震動水壓力的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.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU991.36

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本文編號：2142745