Freeze-thaw (F-T) cycles are a primary contributor of pavement damages in seasonal frost regions. Geosynthetics stabilization has been a promising solution for enhancing the roadways performance in cold regions. However, in comparison with the practical applications, research on the geosynthetics stabilization in cold-region roads is scarce and its efficacy is yet to be quantified. This study presents the full-scale test on geosynthetics-stabilized sections in a flexible pavement in Sturgeon County, Alberta. It focused on the investigation of three separate test sections with bases stabilized by two types of geocells and one geogrid composite, each fully instrumented with earth pressure cells, thermocouples, and moisture sensors. This experimental program consisted of plate loading tests and trafficking tests on each test before and after the first F-T season, and monitoring of soil temperatures, moisture contents, and loads transferred to subbases while the sections were open to general traffic. The results showed seasonal F-T cycles resulted in increased pavement settlement, decreased load transfer ratio, and increased stress distribution angle under the plate loading. The traffic-induced stress on the subbases increased during the spring thaw but decreased afterwards.

Full-scale testing of lateral pressures in expansive clay under various saturation conditions is crucial to better understand the behavior of these soils and predict potential damage to structures. However, due to their complexity and cost, only a few full-scale physical testing studies on expansive soils have been reported in the literature. This study aims to provide new insight into the evolution of lateral swelling pressure in expansive soils under infiltration via full-scale physical testing. For this purpose, a heavily instrumented 3-m high masonry wall backfilled with an expansive clay was built and subjected to infiltration. The backfill was compacted in 95% of standard Proctor at a moisture content near optimal to simulate field conditions. The degree of saturation, pore-water pressure, temperature, suction, and lateral and vertical pressures were monitored at different locations during the test. Results showed that the development of lateral pressure is rapid during initial saturation and levels out as the clay approaches saturation levels. This finding highlights the importance of monitoring lateral pressure over time to accurately predict its behavior. The study also found that lateral pressure develops prior to vertical pressure, depending on the area and restraint. The lack of vertical pressure observed during the test is attributed to the continued displacement of the concrete block wall and settlement of the clay with increased area and wet weight of the soil. This finding is important for backfill against basement walls, retaining walls, and foundation units, where the mass of the expansive soil is limited, and effective stress is limited to one dimension.

Strengthening interconnection and interoperability between water supply groups and reservoirs in super mountainous cities, a large number of water conveyance tunnels need to be built. Jacking prestressed concrete cylinder pipe (JPCCP) has been applied to pipe jacking construction in soil stratum. A new type of JPCCP was proposed to meet the needs of long-distance pipe jacking construction of water conveyance tunnels in rock stratum. However, the frictional resistance of the rock mass-pipe interface is very complicated in engineering practice. It is common for pipe sections to become stuck due to the excessive friction. The mechanical response and deformation characteristics of the new JPCCP when pipe sticking problem occurred have attracted more and more attention. In this paper, the characteristics of concrete strain, steel stress, crack propagation and axial stress transfer under axial jacking force were studied by the combined method of fullscale test and numerical simulation. The full-scale tests results showed that the concrete internal strain and surface strain of the pipe increased with the increase of the axial jacking force. The spigot end was the weakest area, where cracks appeared first and then developed along the circumferential direction in the full-scale tests. The potential causes of pipe cracking in full-scale tests were carefully discussed. It is suggested to improve the mechanical performance of the spigot end. Finally, the numerical simulations further revealed the axial stress transfer characteristics of the new JPCCP.

Compared with circular, arched, and pipe-arched soil-steel structures, box-type soil-steel structures (BTSSSs) have the advantages of high cross- utilization and low cover depth. However, the degree of influence of the crown and haunch radii on the mechanical performance of BTSSSs is still unclear. Therefore, two full-scale BTSSS models with a span of 6.6 m and a rise of 3.7 m but with different crown and haunch radii were established, and the mechanical properties during backfilling and under live load were tested. Afterward, 2D finite element models (FEMs) were established using the ABAQUS 2020 software and verified using the test data. The influence of cross- geometric parameters on mechanical performance was analyzed by using the FEM, and a more accurate formula for calculating the bending moment during backfilling was proposed. The results show that the BTSSS with a smaller crown radius has a stronger soil-steel interaction, which promotes more uniform stress on the structure and makes the structure have smaller relative deformations, bending moments, and earth pressure. The span and arch height greatly influence the bending moment and deformation of the structure. Based on the CHBDC, the crown and haunch radii were included in the revised calculation formula.