Design and analysis tools for steel grid mechanically stabilized earth walls considering corrosion

土木工程中改善地基的技术，如挡土墙，正在迅速发展。仅举一个例子，采用先进的聚合物土壤增强板和钢产品的水平层建造的挡土墙已被证明可以将传统墙体解决方案的成本降低高达50%，并在与旧技术的竞争中提供更可持续的解决方案。在北美的术语中，这些系统被称为机械稳定土（MSE）墙。目前，加拿大岩土工程界正在从用安全系数描述安全边际的分析和设计方法，转向用失效概率描述安全边际的方法，其中包括荷载和阻力系数设计（LRFD）。后者是一种更严格的方法，并使**MSE墙设计与结构工程实践保持一致。MSE墙类别中包括由混凝土面和回填土组成的系统，该系统由镀锌钢网层加固。**这是一项由加拿大大西洋工业有限公司（AIL）从海岸到海岸提供的技术。目前用于这些系统抗拉伸破裂和钢筋土回填中钢网拔出稳定性的模型**已经**了20年，使用最近在现场收集的测量数据的数据库的准确性**尚未得到充分检验。此外，加拿大和美国使用的LRFD规范对相同的钢网类型产生了不同的设计结果，这可能使一些钢土加固供应商（如AIL）处于不利地位。再加上这一挑战，缺乏一种严格而准确的方法来将钢筋的潜在腐蚀纳入钢网MSE墙可靠性的寿命预测中。**钢材腐蚀对MSE钢墙体寿命性能的影响经常被设计师提出。这项与AIL合作研究项目的结果将为AIL提供基于现代性能可靠性的分析和设计工具，包括最低锌（电）涂层的建议。这些将**协助AIL在加拿大，美国和国际上推广使用他们的钢网MSE墙技术。

Technologies to improve the ground in civil engineering earthworks such as retaining walls are advancing**rapidly. As just one example, retaining walls constructed with horizontal layers of advanced polymeric soil**reinforcement sheets and steel products have been demonstrated to reduce the cost of conventional wall**solutions by up to 50% and provide more sustainable solutions in competition with older technologies. In North**American terminology these systems are called mechanically stabilized earth (MSE) walls. Currently the**Canadian geotechnical engineering community is migrating from methods of analysis and design that describe**margins of safety in terms of factors of safety to margins of safety described in terms of probabilities of failure**which include load and resistance factor design (LRFD). The latter is a more rigorous approach and brings**MSE wall design into alignment with structural engineering practice. Included in the MSE wall category are**systems composed of a concrete facing and backfill soil that is reinforced by layers of galvanized steel grids.**This is a technology provided coast to coast by Atlantic Industries Limited (AIL) in Canada. Current models**for stability of these systems against tensile rupture and pullout of steel grids in the reinforced soil backfill are**now two decades old and their accuracy using a database of recently collected measurements in the field has**not been fully examined. Furthermore, LRFD codes used in Canada and the USA produce different design**outcomes for the same steel grid type which can put some suppliers of steel soil reinforcement such as AIL at a**disadvantage. Coupled with this challenge is the lack of a rigorous and accurate approach to incorporate**potential corrosion of the steel reinforcement into lifetime predictions of the reliability of steel grid MSE walls.**The influence of steel corrosion on lifetime performance of MSE steel walls is often raised by designers. The**results of this collaborative research program with AIL will provide modern performance reliability-based**analysis and design tools for AIL including recommendations for minimum zinc (galvanic) coating. These will**assist AIL to promote the use of their steel grid MSE wall technology in Canada, the USA and internationally.