Investigating engineering properties of cemented cohensive soils as foundation support

加拿大西部能源和建筑业的快速发展导致密集城市地区的土地使用急剧增加。在许多开发项目中，不可避免地会遇到土质条件较差的地区和物业。因此，克服在劣质地基上施工困难的补救方案至关重要。深层搅拌(DSM)是一种在现场将土与胶结剂混合的方法，在施工速度和成本方面具有优势。然而，DSM尚未被加拿大建筑业广泛采用，可能是因为在冷环境暴露令人担忧的地区，DSM处理过的土壤的力学和水力性能令人担忧。水泥土在冻融循环(f-t)作用下的研究很少。因此，水泥土在f-t循环作用下的基本工程特性尚不清楚，加拿大粘性土场地中的DSM技术也没有得到实际应用。该计划将研究没有或有f-t暴露的水泥粘性土(或土壤混凝土)的力学和水力特性，并定性地描述在f-t暴露的不同养护龄期的土混凝土试件的微观结构变化。该提案将与凯勒加拿大有限公司合作，后者一直在DSM技术的实践和研究中发挥着重要作用。拟议的方案包括三项任务，为期三年。我们将培养一名博士生和两名硕士研究生，并进行破坏性或非破坏性测试。通过投资这个项目，产业合作伙伴将保持在地基改善行业的领先地位。加拿大的能源基础设施和建筑业将受益于提供一种适合寒冷温度的地基改良技术。

The rapid growth of the energy and construction industries of Western Canada has resulted in dramatic land use in dense urban regions. Areas and properties with poor soil conditions are inevitably encountered in many development projects. As a result, remedial solutions to overcome the difficult construction on poor-quality ground are critical. Deep soil mixing (DSM), which mixes the soil in situ with cementitious agents, has the advantages in the construction rate and cost. However, DSM has not been widely adopted by Canada's construction industry, perhaps due to concerns with the mechanical and hydraulic performance of DSM-treated soils in the areas where the cold-environment exposure is of concerns. Research on cemented cohesive soils subjected to Freeze-Thaw (f-t) cycles has been scarce. Consequently, fundamental engineering behaviour of cemented cohesive soils under f-t cycles has not been clearly understood and the DSM technique in cohesive soil sites of Canada has not been practically applied. The proposed program will investigate the mechanical and hydraulic behaviour of cemented cohesive soils (or soilcrete) without or with f-t exposure, and qualitatively characterize the microstructure changes in soilcrete specimens at various curing ages with f-t exposure. The proposal will be partnered with Keller Canada Ltd., which has been playing a major role in the practice and research of DSM technique. The proposed program consists of three tasks in three-year duration. We will train one PhD and two MSc students and conduct destructive or non-destructive tests. By investing in this project, the industrial partner will maintain the leadership in the ground improvement industry. The energy infrastructure and construction industry of Canada will benefit from the provision of a ground improvement technique that is suitable to the cold temperature.