Recently, the road and railways infrastructure developments in Norway have led to renewed interests on the geotechnical challenges associated with slope stability under freezing-thawing cycles. Despite the amount of research available on the topic, there are few comprehensive studies involving laboratory testing, numerical analysis, and field monitoring of a slope during a freezing–thawing. In this case study, a critical slope was identified in a cold region based on field and laboratory tests, and a series of numerical simulations were carried out to evaluate the governing factor of slope stability using finite element methods. A remote monitoring system was installed on a real scale man-made slope to observe its behavior against the governing factors of slope stability. As a result, it was found that slope stability at the critical slope was significantly impacted by the freezing–thawing action, which was confirmed by the initial field observations from 2019 to 2020. Later, continuous monitoring data could be used to update soil parameters and to implement an early warning system for the high risky slope areas effected by freezing–thawing action in many cold regions.

Offshore wind-turbine support structures are largely made of steel since steel monopiles have accounted for the majority of installations in the last decade. As turbines become bigger, steel structures have led to an exponential increase in material and installation costs. From this point of view, the use of concrete for future support structures has been initiated. In this study, concrete–steel composite piles have been investigated. A pre-tensioned high strength concrete pile was placed in the lower part, mainly to support the axial load, and a steel pile in the upper part to resist the lateral load. A mechanical joint was adapted to connect the two different types of piles. Static axial, dynamic axial, and lateral load tests were performed to evaluate the load-displacement response of the composite pile, verify the integrity of the mechanical joint, and investigate its potential application to offshore wind foundations. This paper focused on the load-displacement response and the connection integrity; in particular, it investigated the lateral load-displacement response by comparing it to the results of beam-spring analysis. Based on the results from the field tests, a site-specific lateral load-displacement curve was suggested, and the connection integrity was verified.

Ground conditions comprised of slightly or completely weathered rock are frequently encountered in design of bridge foundations in Korea. It is rather challenging to assess the accuracy of the common design methodologies for shallow foundations in these ground conditions as the foundation bearing capacity depends on the degree of weathering. This paper presents reliability-based derivation of resistance factors for the bearing capacity of shallow foundations on slightly and completely weathered rock using field plate load test data. More than 140 plate load tests were performed at 52 sites, 33 of which were considered to be of high quality and reliable. These high-quality tests were used to evaluate the uncertainties associated with the bearing capacity equations, and the resistance factors corresponding to current prescribed load factors. A reliability-based approach, with target annual failure probabilities of 1.0 × 10−3, 2.0 × 10−4, 1.0 × 10−4, was adopted to estimate the required resistance factors for different design equations. A Bayesian approach was adopted to facilitate quantification and propagation of statistical parameter uncertainty due to limited available data. The best estimates of the calibrated resistance factors range from 0.40 to about 0.47 for the considered target reliability levels, which is in good agreement with currently used values in Korea.