长输管线大变形设计理论研究

【作者】 童华；

【导师】 陈小榆； 练章华；

【作者基本信息】 西南石油学院 ， 油气储运工程， 2005， 硕士

【摘要】 本文是由省部级项目:四川省杰出青年基金项目(编号:03ZQ026-044)“特殊类型井管柱、管线设计与选择”资助完成的,也是该项目的部分内容之一。 油气长输管线由于大变形引起的损伤在国内外长输管线失效事故资料统计分析中占了相当大比例,它是导致长输管线失效破坏的一个非常重要因素。我国在长输管线强度设计理论和设计规范方面的研究非常少,基本都是参照国外的设计规范,但工程实践表明目前的管道强度设计中存在许多问题,与实际情况存在较大差异,常会造成重大事故和巨大经济损失。因此,研究长输管线的大变形设计理论并对国内现行设计规范作出必要的修正具有重要的工程意义。 本文是一项涉及地质力学、土力学和固体力学的交叉学科的研究,综合运用了弹塑性力学理论和计算机仿真方法,在前人基础上对长输埋地管道和跨越管道的几类典型大变形情况进行力学理论分析和计算机仿真分析,初步形成系统的长输管线大变形分析理论和研究方法,得到了一些深入认识,主要包括以下几方面: (1) 建立了上凸初始弯曲管段的大变形失稳分析模型;提出对现行规范中临界纵向力计算的安全性、横向阻力计算、荷载系数的取值等的修正意见和建议。 (2) 基于管土互作用双线性模型、Winkler假定,建立了水平弯头的变形分析模型;在CAESAR Ⅱ二次开发基础上作计算机仿真分析,验证了公式的适用性;提出了对现行规范中弯头强度校核方法、管土互作用参数选择等的修正建议。 (3) 基于弹性地基理论和弹性梁挠曲理论建立了埋管在坍塌/冲沟地质灾害作用下的变形微分方程,导出了大变形分析模型;以西气东输工程用管为例,由计算机仿真验证了公式适用性,确定了管道失效长度并提出了预防建议。 (4) 基于大挠度梁理论,考虑几何非线性和土壤的物理非线性建立了跨越管道的大变形分析模型;通过5种典型工况下跨越管道变形的计算机仿真分析验证了公式适用性,对跨越管道固定墩的设置问题给出了建议;提出了一些关于现行规范中跨越管强度验算的修正建议。 (5) 对埋地和跨越管道补偿器设计作了初步研究,建立了确定位置和吸收位移的数学模型及其求解框图;提出了对补偿器强度设计规范的几点修正建议。更多还原

【Abstract】 This paper belongs to the project of preeminent youth fund of si chuan province (No. 03ZQ026-044) "The design and choice of special well tubal and pipelines ",and is a part of it.The damnification of long pipelines caused by large deformation is a big part of domestic and foreign invalidation accidents of long pipelines, and is an important factor of invalidation for long pipelines. There is little domestic investigation on long pipelines’ intensity design theory and criterion, and most is refered to foreign design criterion. So, it’s very necessary and important to study the theory of large deformation design and make essential corrections to domestic criterions.This paper studies long pipelines’ several typical lage deformation behaviors by geomechanics, soil and solid mechanics and compute the created models by the way of elasticity and plastic theory and computer emulation, and establish systemic large deformation analysis theory and research method of long pipelines, and results are:(1) Establish the large defaormation of original up-protruding bend pipelines and bring forward several suggestions on the security of critical axial force calculation etc. in active criterions.(2) Establish the horizontal elbow’deformation formulas under the bilinear model, Winkler model etc.; simulate and validate these formulas; put forward some suggestions on intensity check method of bend in active criterions.(3) Establish large deformation model of pipes under geologic disasters such as collapse and gulch; simulate and validate these formulas, and make certain of pipe’ lapse length, and put forward some defendable suggestions.(4) Establish large deformation model of pipeline span, simulate and validate these formulas; give ideas on the set of frusta; put forward several suggestions on correlative criterions.(5) Make primary research on the design of compensator, and establish the calculation models of compensator’s position and absorbed displacement; contrast and make some corrections to the intensity design of compensator in active criterions.更多还原