Investigating engineering properties of cemented cohensive soils as foundation support

加拿大西部能源和建筑业的快速增长导致了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壤条件差的地区和地产。因此，必须采取补救办法，克服在质量差的地面上施工的困难。深层搅拌法是将水泥土就地搅拌，在施工速度和成本方面具有优势。然而，DSM并没有被加拿大的建筑业广泛采用，这可能是由于在寒冷环境暴露的地区，DSM处理过的土壤的机械和水力性能的问题。冻融循环对水泥土的影响研究较少。因此，在f-t循环下水泥粘性土的基本工程行为还没有被清楚地理解，DSM技术在加拿大粘性土场地还没有实际应用。本计画将探讨水泥黏性土（或混凝土）在无或有f-t曝露下之力学及水力特性，并定性地描述混凝土试件在不同养护龄期及f-t曝露下之微结构变化。该提案将与凯勒加拿大有限公司合作，在电力需求侧管理技术的实践和研究中发挥了重要作用。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生，并进行破坏性或非破坏性测试。通过投资该项目，工业合作伙伴将保持在地面改善行业的领导地位。加拿大的能源基础设施和建筑业将受益于提供适合寒冷温度的地面改良技术。

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.