This study presents a new experimental procedure for evaluating the durability of stabilized soils subjected to multiple wetting and drying (W-D) cycles. An integrated experimental program combining dynamic shear rheometer (DSR) testing with W-D cycles was designed and implemented to assess moisture-induced performance degradation in natural sand stabilized with two types of rapid-setting cementitious stabilizers. Small cylindrical specimens (10.5 mm in diameter and 35.0 mm in height) of stabilized sand mixes were compacted, cured, and subjected to up to seven W-D cycles. Each W-D cycle was meticulously controlled to gauge its impact on the material's durability. The mechanical properties of the stabilized samples were evaluated at different stages of the W-D cycles using the strain-sweep DSR testing based on a methodology developed from preliminary work. The proposed test method focuses on the shear properties of the material, measuring its mechanical response under the torsional loading of a cylindrical sample and providing dynamic mechanical properties and fatigue-resistance characteristics of the stabilized soils under cyclic loading. Test results demonstrate water-induced deterioration of stiffness and reduced resistance to cyclic loading with good testing repeatability, efficiency, and material-specific sensitivity. By combining dynamic mechanical characterization with durability assessment, the new testing method provides a high potential as a simple, scientific, and efficient method for assessing, engineering, and developing stabilized soils, which will enable more resilient transportation infrastructure systems.

Triaxial tests has been routinely used to measure the stress-strain relationship for geomaterials. During triaxial testing, many sources of errors that cannot be completely avoided but are often ignored or approximated using empirical equations. This paper presents a systematic investigation of soil volume change, volume strain nonuniformity, and cross-sectional calculation along the specimen during triaxial testing using a photogrammetry-based method. Consolidated drained triaxial tests were performed in which two parallel measurements were taken: (1) relative volume using the conventional triaxial testing and (2) absolute volume using the photogrammetry-based method. The difference in the observed volume and void ratio measurements between the two methods highlighted the importance of absolute soil volume over the relative volume method. The results revealed the effect of soil volume change in the interpretation of triaxial testing findings. Various preparation steps and procedures during triaxial testing have influenced the initial measured volume and thus caused deviation of the subsequent associated measurements. This method would present a quality control approach for different aspects of triaxial testing to improve the test simulations to accurately measure the soil behavior. The proposed method is important for more refined simulations and identification of setup-induced errors. Additional applications of the current research would allow correct determination of the stress path followed during triaxial testing, the critical-state soil mechanics parameters, and the stress-strain relationship, including deformation and strength parameters.

This paper focuses on evaluating the increase in axial pile resistance subjected to both consolidation and aging setups. Consolidation and aging setup models were first developed to estimate the setup parameters based on databases collected from literature, which include 10 instrumented piles for consolidation setup and 26 test piles for long-term aging. The eight top-performing pile cone penetration test (CPT) methods that were evaluated in a previous study were used to estimate the side resistance of soil layers at 14 days after pile driving. The developed consolidation and aging setup models were then used to extrapolate the results to evaluate the side resistance of each soil layer at the end of consolidation and for long-term aging. The estimated side and total resistances were compared with the measurements from pile load tests considering both consolidation and aging setups. The resistances estimated before and after completion of excess pore water pressure dissipation indicates that significant aging takes place after consolidation setup. The value of consolidation setup parameter (Ac) was 0.53, and, for aging, the setup parameter (Ag) was 0.23 in clay and 0.16 in sand. The results show that all pile CPT methods with/without using a consolidation setup model tend to underestimate the unit side resistance of clay soil layers. The use of pile CPT methods in combination with an aging model improved the accuracy of pile CPT methods, and this was verified using load test results for five piles subjected to aging. The Philipponnat and University of Florida (UF) methods showed the best performance on estimating the total resistance of piles subjected to aging.

Streambed scour in cohesive sediment is complex because erosion processes depend on the physical, geochemical, and biological properties of the sediment. The scouring processes can also be characterized as a slow fatigue phenomenon. Therefore, repetitive hydraulic loadings from multiple stormflow events are likely necessary for equilibrium scour depths to develop in cohesive sediment compared with non-cohesive sediment. Cumulative effective stream power, which is a surrogate measure of effective stream power duration, showed a significant relation with scour development and propagation in cohesive sediments around bridge piers, where results from this study identified a statistically significant correlation between cumulative effective stream power and the observed scour depths around different bridge piers (R-2 = 0.56, p < 0.001). However, some localized and site-specific variations were observed. It was also observed that scour depth development in cohesive soil appeared to be dependent on effective shear duration, rather than the number of flow events above erosion threshold values. In addition, the relationship between an erodibility index (K) and critical stream power showed a significant statistical correlation (R-2 = 0.61, p = 0.017). Results from this study deviated from the Annandale empirical relationship for sediments when K < 0.1. This finding supports that site-specific critical stream power should be measured using an empirical relationship for cohesive bed sediments to predict scour depths.