地下供水管线抗震性能分析

发布时间：2018-06-18 12:23

本文选题：地下供水管线 + 柔性接口　；参考：《沈阳建筑大学》2015年硕士论文

【摘要】：地下供水管线遍布人类生活环境中的每个角落,有人称之为现代城市的输血动脉。伴随大城市现代化进程的快速跃进,人们对于地下供水的需求度越来越高。一旦无法及时供水,就将给各行各业造成不可挽回的损失。地震正是导致地下供水管线功能失效的最主要原因,历年来重大地震往往会导致地下供水管线大面积瘫痪,从而引发灾后次生问题,例如火灾、疾病传播等。因此,提高地下供水管线抗震性能具有重要意义。关于地下供水管线抗震性能的研究,目前大多关注在管线管体的破坏方面。但是,地下管线震害调查资料表明：接口破坏是地下管线震害的主要形式。目前,工程中多采用承插式柔性接口连接地下管线,因此,对柔性接口地下管线抗震性能的研究具有重要的科研和工程意义。本文采用ANSYS有限元软件对柔性接口地下管线地震响应进行研究,为柔性接口地下管线的工艺参数优化、地震失效分析与预防提供了理论依据。本文主要研究内容和主要研究结论如下所述。基于有限元软件ANSYS,建立具有柔性接口地下管线以及周围土体的数值模型,该数值模型由3段9米长管段、2个承插式接口、周围土体组成,管材为球墨铸铁材质,场地土为Ⅲ类环境。按照《建筑抗震设计规范》中设防要求,选取El-centro地震波,通过调整地震波的峰值加速度对土体施加烈度7度地震,并在土体指定位置采用大质量法实现地震波的纵波输入与横波输入。此外,通过改变数值模型参数,对比研究了不同管段长度、管径、埋深以及地震烈度下的供水管线地震响应,提出上述因素对柔性接口地下管线抗震性能的影响规律。(1)地下供水管线主要破坏形式为承插式柔性接口的拔出和管体破裂,通过数值模拟,提取接口最危险点位移和管体最危险点应力的计算数据,研究结果表明：III场地土、7度地震情况下,承插式接口最大位移为63mm,发生部分渗漏现象；管体最大Mises应力为78MPa,远未达到球墨铸铁的极限强度,柔性接口极大程度地降低了管体应力。(2)管径对柔性接口地下供水管线的抗震性能具有一定的影响。随着管径的增大,管线管体Mises应力、承插式接口的拔出位移相应降低。因此,与大口径管线相比,小口径管线在地震作用下更容易遭到破坏。进行管线抗震设计时,在满足其它指标要求的情况下,可以考虑将尽量选取大口径管线,能够在一定程度上提高管线的抗震性能。(3)埋深对柔性接口地下供水管线的抗震性能具有一定的影响。随着埋设深度的增加,管体Mises应力、承插式接口的拔出位移相应降低。同时考虑到管线铺设工作,埋设深度也不宜过深,应在保证安全的前提下,选取适宜的深度进行埋置。(4)管段长度对柔性接口地下供水管线的抗震性能具有一定的影响。随着管段长度的增加,地下管线总体刚度相应增大,这将导致地震作用下的管线管体Mises应力、承插式接口的拔出位移相应增大。但考虑到地下管线铺设过程中的连接工作量,管段长度也不宜过短,内径200mm的地下管线单根管段长度以9m为宜。(5)地震烈度对柔性接口地下供水管线的抗震性能至关重要。随着地震烈度的提高,管线管体Mises应力、承插式接口的拔出位移急剧增大,管线泄漏的潜在风险明显提高,研究结果表明：6度地震情况下,管线接口处基本不发生泄露；7度地震情况下,管线接口处因发生拔出位移而导致部分泄漏现象；8度地震情况下,管线接口几乎完全拔出,地下供水管线的输运功能完全丧失。
[Abstract]:The underground water supply pipeline is all over the human living environment, which is called the blood transfusion artery in the modern city. With the rapid progress of the modernization process in the big cities, the demand for underground water supply is getting higher and higher. Once the water supply is not timely, it will make irreparable loss to all walks of life. The earthquake is the cause of the underground. The main reason for the failure of water supply pipelines is that major earthquakes in the past years often cause large area paralysis of underground water supply pipeline, thus causing secondary problems after disaster, such as fire and disease transmission. Therefore, it is of great significance to improve the seismic performance of underground water supply pipeline. However, the investigation data of the earthquake damage of the underground pipeline shows that the failure of the underground pipeline is the main form of the earthquake damage of the underground pipeline. At present, the underground pipeline is connected with the flexible interface with the flexible interface. Therefore, the research on the seismic performance of the flexible interface underground pipeline has important scientific and engineering significance. This paper adopts the ANSY The seismic response of the underground pipeline with flexible interface is studied by the S finite element software, which provides a theoretical basis for the optimization of the technological parameters of the underground pipeline of the flexible interface, the analysis and prevention of earthquake failure. The main research contents and main conclusions are as follows. Based on the finite element software ANSYS, the underground pipeline with flexible interface and its surrounding is established. The numerical model of soil is composed of 3 sections of 9 meters long tube section, 2 socket interface, surrounding soil body, pipe material as ductile iron material and ground soil type III environment. The El-centro seismic wave is selected according to the requirements of the "code for seismic design of buildings", and the seismic wave peak acceleration is adjusted to apply the intensity of 7 degree earthquake to the soil. The seismic wave input and transverse wave input are realized by the large mass method at the designated soil position. In addition, by changing the parameters of the numerical model, the seismic response of the water supply pipeline with different length, diameter, depth and earthquake intensity is compared and studied. The influence of the above factors on the seismic performance of the flexible interface underground pipeline is proposed. (1) The main failure mode of the lower water supply pipeline is the pulling out of the socket type flexible interface and the rupture of the pipe body. Through numerical simulation, the calculation data of the most dangerous point displacement of the interface and the most dangerous point stress of the pipe body are extracted. The results show that the maximum displacement of the socket type interface is 63mm under the 7 degree earthquake, and the pipe body is the most important. The stress of large Mises is 78MPa, which is far from the ultimate strength of ductile iron, and the flexible interface greatly reduces the stress of the tube. (2) the pipe diameter has a certain influence on the seismic performance of the underground water supply pipeline with flexible interface. With the increase of the pipe diameter, the Mises stress of the pipe pipe and the pull out displacement of the socket type interface are reduced accordingly. Compared with the pipeline, small caliber pipeline is more easily damaged under the earthquake action. When the pipeline seismic design is carried out, the large diameter pipeline can be selected as much as possible to improve the seismic performance of the pipeline to a certain extent. (3) the seismic performance of the underground water supply pipeline with the flexible interface is one of the most important. With the increase of the buried depth, the Mises stress of the pipe body and the pull out displacement of the socket interface are reduced accordingly. Considering the pipeline laying work, the buried depth should not be too deep, and the suitable depth should be selected under the premise of ensuring safety. (4) the seismic performance of the pipe length to the underground water supply pipeline of the flexible interface is of great importance. With the increase of the length of the pipe section, the overall stiffness of the underground pipeline increases correspondingly. This will lead to the Mises stress of the pipeline body under the earthquake action, and the pull out displacement of the socket interface increases accordingly. But considering the connection workload in the laying process of the underground pipeline, the length of the pipe section should not be too short, and the inner diameter of the underground pipeline is 200mm single pipe. The length of the section is 9m. (5) the earthquake intensity is very important to the seismic performance of the underground water supply pipeline with flexible interface. With the enhancement of the earthquake intensity, the Mises stress of the pipe pipe body, the pulling displacement of the socket type interface increases sharply, and the potential risk of the pipeline leakage is obviously improved. The research results show that the pipeline interface is basically not under the condition of 6 degree earthquake. Leakage occurred. In the case of 7 degree earthquake, partial leakage occurred at the pipeline interface due to the occurrence of pull out displacement. In the case of 8 degree earthquake, the pipeline interface was almost completely pulled out, and the transport function of the underground water supply pipeline was completely lost.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU991.33

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