Finite element analyses of corroded pipeline with single defect subjected to internal pressure and axial compressive stress

This paper describes the application of finite element method (FEM) and the development of equations to predict the failure pressure of single corrosion affected pipes subjected to internal pressure and axial compressive stress. The finite element analysis (FEA) results were verified against full-scale burst tests and theoretical calculations. Material non-linearity, which allow for large strains and displacements, were considered. In addition, true UTS instead of engineering UTS was used to determine the point of failure. The pipes used in the FEA was modelled based on API 5L X52 modified steel with a length of 2000 mm, a nominal outer diameter of 300 mm, and a nominal wall thickness of 10 mm. The results obtained from FEA were compared to that of existing comprehensive corrosion assessment method, known as DNV-RP-F101. Six equations, utilizing the Buckingham's π theorem and multivariate non-linear regression techniques, were developed for predicting the failure pressure of corroded pipeline with single defect subjected to both internal pressure and axial compressive stress. These equations provide improved failure pressure predictions with good margins of errors (less than 10%).     

Algorithmic formulation of clay and sand pipe–soil interaction models for on-bottom stability analysis

This paper presents a new algorithmic formulation of the clay and sand pipe–soil interaction models recommended by the DNV-RP-F109 code for dynamic on-bottom stability analysis of submarine pipelines. The pipe–soil force update algorithm is formulated within the framework of computational elasto-plasticity and applies Backward-Euler integration to ensure stability and robustness for large time step sizes. Algorithmic optimization techniques are developed by utilizing a closed-form solution and subincrementation. A numerical verification study covering full cyclic displacement ranges of a 12 inch pipeline is presented. The new formulation is shown to increase the time step size by a factor of up to 50 compared to commercial software tools for on-bottom stability analysis. This achievement will be particularly beneficial for long-duration 3D nonlinear time domain on-bottom stability analysis.     

浅谈化工厂区室外给排水设计

室外给排水设计是整个化工厂区室外管线设计的重要部分。本文介绍了石油化工企业给水排水管道工程设计中优化设计方案、管线综合规划、管线高程、管材选用、接口方式及管网附件、管道防腐、附属构筑物等方面的经验。     

波纹钢板管涵在A30公路中的应用

场拼装式波纹钢板管涵结构属新型技术,通过对该管涵结构在A30公路北段工程中的应用效果的调查,表明波纹钢板管涵能适应软土地基路堤的沉降变形、有利于改善软土地基结构物与路堤交界处的“错台现象”,提高行车的舒适度与安全性。     

港珠澳大桥珠海连接线拱北隧道曲线管幕9号管脱困方案研究

港珠澳大桥拱北隧道曲线管幕施工阶段,由于始发端深基坑突发涌水、涌砂,造成顶管施工区域地层严重失水和管周润滑泥浆流失,9号管顶进被困。根据顶管施工区域工程环境、地质条件和地层变形情况,以及9号管被困位置和施工装备条件因素,按照"不危及施工安全和避免发生次生灾害,可操作性强,处置费用低"的原则,提出了增加后背顶力、中继套管顶推、逆向开挖拉拔、顶部开窗等4种递进脱困方案。经比选,首先采用了增加后背顶力方案未果,后采用中继套管推进方案,取得了成功。9号管成功脱困为本工程后续顶管施工积累了经验,也为类似工程施工提供了借鉴。     

用翻衬工艺实现旧管线的更新改造

对于市政埋地管道的维修更换 ,传统上采用大开挖的施工工艺 ,对周边环境和生产生活影响巨大 ,甚至无法实施 ,因此 ,产生了多种免开挖施工工艺。对其中的翻衬工艺进行了全面的介绍 ,通过场地试验证实了其用于市政埋地管道更新的可行性 ,并为工程应用的施工预算积累了基础数据     

智能弯管回弹伸长测量仪的研制及应用

本文介绍了一种配合弯管机使用的、专门用于测量弯管回弹与伸长规律的智能化仪器。它的理论模型建立在分析实验数据以及进行理论计算所得到的管子弯曲加工时回弹与伸长规律的基础上。简单介绍了它的组成，相应的应用软件，使用方法及使用情况，该仪器是开展夫余量变管，先焊后弯新工艺的必备仪器。     

筑路机械施工中的困境救援

筑路机械施工中的困境救援西安公路学院郑忠敏ＰｉｐｅｊａｃｋｉｎｇＴｅｃｈｎｏｌｏｇｙ￥ＴａｎｇＹｕａｎｎｉｎｇＡｂｓｔｒａｃｔ：ｌｎｔｒｏｄｕｃｅｄｔｈｅａｄｖａｎｔａｇｅｓａｒｉｄａｐｐｌｉｃａｔｉｏｎｒａｎｇｅｏｆａｐｐｌｉｎｇｔｈｅｐｉｐｅｊａ...     

MSEMD排气系统扩压长支管定常流动研究

本文用数值方法研究了ＭＳＥＭＤ系统轴对称扩压长支管的定常流动特性。在贴体坐标系中用与时间相关的二维流动计算方法对湍流流动的控制方程进行了数值求解，用二阶ＭａｃＣｏｒｍａｃｋ差分方法处理内部节点，用二阶参考平面上的特征线法处理进、出口边界条件，并把计算结果与实测结果进行了比较，它们之间吻合得相当好。     

新型水下RTP管楔块夹紧式接头设计与分析研究

针对适用于水下的6英寸非金属粘结性RTP管,设计了新型的楔块夹紧式接头。使用SolidWorks软件进行了结构设计,并基于有限元理论建立了有限元分析模型,采用ABAQUS有限元分析软件对楔块夹紧式接头系统在极限工作内压和轴向拉伸条件下进行静态分析。得到了该新型楔块夹紧式接头系统在极限工作内压条件下的Von Mises应力、接触应力和剪切应力,并按照DNV设计规范对接头所受应力进行校核,验证了新型楔块夹紧式接头系统的设计可行性与结构可靠性,同时探究了该楔块夹紧式接头在设计制造以及安装时遇到的一些问题,给出了相关的设计、加工、安装和使用方面的建议,为国内水下油气管线的发展和使用提供帮助。