断层作用下埋地管道接口力学性能的试验研究

发布时间：2018-04-15 19:17

本文选题：断层 + 埋地管道　；参考：《华北理工大学》2017年硕士论文

【摘要】：埋地管道是为人们供暖、供水以及输送石油、天然气等的重要手段,与人们生活有密切的联系。但是多次震害表明,断层对埋地管道的破坏作用非常大,而接口位置又是管道的薄弱部位。所以研究断层错动对埋地管道接口力学性能的影响就显得十分必要。本文通过室内三箱装置的加载试验,模拟各种断层作用,研究埋地管道接口的力学反应。将钢质管道埋置于项目组自行研发的土箱体内,向管道内充入2.5MPa的常温自来水,利用MTS设备和千斤顶装置使箱体产生不同方向的位移,从而模拟断层错动。断层类型分别为正断层、逆断层和走滑断层,接口类型分别为焊接、螺纹连接和法兰连接;接口位置分别在断层处和非断层处。并与无接口管道和无压力管道的试验结果进行对比。模拟正、逆断层试验中,根据管道埋设所经过的箱体数量,分为两箱体模型和三箱体模型。通过分析管道各处应变、管道位移、水压与箱体位移之间的关系,得出断层作用下埋地管道接口的变形与破坏规律,主要结论如下:焊接接口在正断层、逆断层和走滑断层分别作用下变形最小,并且强度略高于直管,与管道保持较高的一致性,有一定抵抗大位移断层的能力,并可以保持管内水压稳定,所以埋地管道最适宜用焊接接口。螺纹接口在正断层、逆断层和走滑断层分别作用下变形比直管大,断层位移较小时管道在断层处位移最小,可以保持管内水压稳定,断层位移较大时管内水压会有轻微泄露,所以断层位移较小时可用螺纹接口连接管道。法兰接口在走滑断层作用下会发生严重破坏,管内水压急降,所以不宜选择法兰接口连接管道。埋地管道变形最大的部位在断层两侧一定距离(本文为100mm到500mm之间,接近300mm),且应变随着断层位移的增大而增大,所以接口埋设应尽量避开此处。对比正、逆断层作用下两种箱体模型,无论接口位置在哪,三箱体模型中的管道接口下表面更容易破坏,两箱体模型中接口靠近固定区的一侧更容易破坏。管内有2.5MPa稳定水压的管道比无内压的管道变形大,更容易破坏,需加强保护。
[Abstract]:Buried pipeline is an important means of heating, supplying water and transporting oil and natural gas, which is closely related to people's life.But many times of earthquake damage show that the fault has great damage to buried pipeline, and the interface position is the weak part of pipeline.Therefore, it is necessary to study the effect of fault dislocation on the mechanical properties of buried pipeline interface.In this paper, the mechanical reaction of buried pipeline interface is studied through the loading test of three boxes in the laboratory to simulate the action of various faults.The steel pipe is buried in the earth box developed by the project group and filled with the normal temperature tap water of 2.5MPa. The displacement of the box in different directions is made by using MTS equipment and Jack device, and the fault dislocation is simulated.The types of faults are normal faults, reverse faults and strike-slip faults, and the types of joints are welding, threaded connections and flange connections, respectively, and the positions of the joints are at the fault and non-fault, respectively.The results are compared with the test results of no interface pipe and no pressure pipeline.According to the number of tanks embedded in the pipeline, there are two box models and three box models in the simulated normal and reverse fault tests.By analyzing the relationship between the strain, displacement, water pressure and displacement of the box, the deformation and failure law of buried pipeline interface under the action of fault are obtained. The main conclusions are as follows: welding interface is on the normal fault,Under the action of reverse fault and strike-slip fault respectively, the deformation is minimum, and the strength is slightly higher than that of the straight pipe, which keeps high consistency with the pipeline, and has the ability to resist the large displacement fault, and can keep the water pressure in the pipe stable.So buried pipeline is the most suitable to use welding interface.Under the action of normal fault, reverse fault and strike-slip fault, the threaded interface deformation is larger than that of the straight pipe, and the pipeline with small fault displacement is the smallest displacement at the fault, which can keep the water pressure in the pipe stable, and there will be slight leakage of the water pressure in the pipe when the fault displacement is large.So the fault displacement can be connected to the pipe with thread interface when the displacement is small.The flange interface will be seriously damaged under the action of strike-slip fault, and the water pressure in the pipe will drop sharply, so it is not advisable to choose the flange interface to connect the pipe.The maximum deformation of buried pipeline is located at a certain distance between the two sides of the fault (in this paper, between 100mm and 500mm, it is close to 300mm, and the strain increases with the increase of fault displacement, so the interface embedding should avoid it as far as possible.Compared with the two box models under the action of positive and reverse faults, no matter where the interface position is, the surface of the pipe interface in the three-box model is easier to destroy, and the side of the interface near the fixed area is easier to destroy in the two box models.The pipe with 2.5MPa stable water pressure is more deformed than the pipe without internal pressure, so it needs to be protected.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U173

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