Testing, analysis and performance of new and existing buried pipes installed using conventional and trenchless technologies

安装、修理和更换埋在地下的下水道、水管和能源管道涉及巨额开支。例如，《2012年加拿大基础设施报告》指出，“处于“一般”至“非常差”状况的废水处理基础设施的重置成本为390亿加元”。下水道和水管漏水造成的天坑危及地面的交通和基础设施。生命线故障的风险包括水的损失或水管损坏造成的洪水，以及石油和天然气管道泄漏造成的爆炸或环境污染造成的成本可能非常可观（2010年密歇根州Enbridge管道破裂后，超过7亿美元用于清理）。申请人和其他人已经广泛研究了新埋管在上覆压力下的二维强度极限。然而，刚性污水管在使用寿命结束时的稳定性受管道结构断裂的控制，管道结构断裂可能是由于管道旁土壤通过泄漏接头受到侵蚀而引起的，如果这些侵蚀空隙需要在使用衬里修复污水管之前进行修复，以及如何进行修复，则需要提供指导。还需要关于钢筋混凝土下水道中钢筋腐蚀影响的资料。此外，由沿沿着连续和连接的管道的不均匀地面运动产生的载荷可引起故障，并且现在在拥挤的城市地区广泛使用的管道更换或安装的非开挖方法可损坏邻近的管道基础设施。这项发现补助金将支持一项研究计划，调查控制“多少管道和/或土壤恶化是太多的恶化？在土壤或管道修复之前和之后，土壤-管道相互作用随劣化而发生的变化，差异地面运动对水、石油和天然气输送管道的影响，以及与非开挖施工相关的管道损坏问题。其目标是为新管道或更换管道的设计和施工、劣化管道的评估及其修复制定新的和扩展现有的指南。** 一号。对由于侵蚀进入泄漏的下水道而导致的土壤空隙进行的开创性调查将是第一次测量空隙对管道强度的影响以及空隙一旦被灌浆或聚合物泡沫填充的影响。孔隙几何形状和管道响应的测试数据将支持使用衬管修复之前和之后的土壤孔隙的计算机建模。土壤空洞可能会产生最灾难性的市政管道故障（人行道或其他结构下的天坑将公共和其他基础设施置于危险之中）。此外，粘土和混凝土下水道的长期失效可能是由于接缝的侵蚀造成的，这些过程的确认将加强开发具有更长寿命的管道的努力。2.将使用埋管测试和分析来检查移动地面中的压力管道响应。如果管道穿过不稳定的斜坡或地震断层，或者由于非开挖施工方法（如静态管道爆破和定向钻井）引起变形，则将检查管道弯曲和故障。新的测试、分析和设计程序可以提高管道的安全性和经济性。 ** 在总干事供资的五年期间，提出了两个主题领域的13个研究生项目。四名MASc和九名博士生将从事项目工作，获得开创性的测试结果，开发新的计算机分析方法，为管道和涵洞安装，评估和设计制定新的或改进的程序，并获得岩土和/或结构工程方面的专业知识，以及对行业具有重要价值的前沿分析，测试和设计能力。

The installation, repair and replacement of buried sewer, water and energy pipes involves huge expenditures. For example, the 2012 Canadian Infrastructure Report card states "the replacement cost for the wastewater infrastructure in "fair" to "very poor" condition is $39 billion". Sinkholes from leaking sewers and water pipes endanger traffic and infrastructure at the ground surface. Risks from lifeline failures include loss of water or flooding from damaged water mains, and the costs resulting from explosions or environmental contamination from leaking oil and gas pipelines can be very substantial (>$700M was spent on cleanup after the Enbridge pipeline rupture in Michigan in 2010).**The two dimensional strength limits of new buried pipes under overburden pressures have been studied extensively by the applicant and others. However, rigid sewer pipe stability at the end of service life is controlled by fracture of the pipe structure, likely caused by erosion of the soil beside the pipe through leaking joints, and guidance is needed if these erosion voids require repair before the sewer is rehabilitated with a liner, and how to do so. Information is also needed on the impact of corrosion of steel in reinforced concrete sewers. Furthermore, the loading that results from nonuniform ground movements along continuous and jointed pipelines can induce failure, and trenchless methods of pipe replacement or installation now used widely in congested urban areas can damage adjacent pipe infrastructure. This Discovery Grant will support a program of research investigating the factors controlling `how much pipe and/or soil deterioration is too much deterioration?', the changes to soil-pipe interaction that occur with that deterioration, both before and after repair of the soil or pipe, the impact of differential ground movements on water, oil and gas transmission pipelines, and pipeline damage issues associated with trenchless construction. The goal is to develop new and extend existing guidance for design and construction of new or replacement pipes, the assessment of deteriorated pipes, and their repair. **1. A seminal investigation into soil voids due to erosion into leaking sewers will be the first to measure void impacts on pipe strength and the influence of the void once filled with grout or polymer foam. Test data on void geometry and pipe response will support computer modeling of soil voids before and after pipe repair using liners. Soil voids likely produce the most catastrophic municipal pipe failures (sinkholes under pavements or other structures place the public and other infrastructure at risk). Also, the long term failure of clay and concrete sewers likely results from such erosion through joints, and confirmation of these processes will strengthen efforts to develop pipes with improved longevity.**2. Pressure pipe response in moving ground will be examined using buried pipe tests and analyses. Pipeline bending and failure will be examined where pipes pass across unstable slopes or earthquake faults, or where deformations are induced by trenchless construction methods such as static pipe bursting and directional drilling. The new testing, analysis and design procedures can improve both pipeline safety and economy. **Thirteen graduate student projects in the two theme areas are being proposed over the 5 years of DG funding. Four MASc and nine PhD students will work on projects obtaining seminal test results, developing new methods of computer analysis, producing new or improved procedures for pipe and culvert installation, assessment, and design, and acquiring specialised expertise in geotechnical and/or structural engineering, and leading-edge analysis, testing and design capabilities of great value to industry.