ABSTRACT Performance of pile foundations is significantly influenced by the micromechanical behaviour of the pile–soil interface. In frozen ground, the interface behaviour is temperature-dependent and viscous. This study examines the pullout behaviour of a single pile embedded in frozen soil using a two-dimensional axisymmetric finite element model developed with Abaqus software. A cohesive zone model (CZM) is employed along with a penalty type contact interaction to represent the interface behaviour while a time-hardening power-law creep model is used to simulate the viscous response of the interaction. The model is coupled with temperature and verified by data from temperature-controlled laboratory pullout and creep tests of model pile in frozen sand. The findings demonstrated that CZM effectively describes the behaviour of the frozen interface. Conceptual models that account for non-uniform temperature profiles and variable temperature time-series, showcase the significant influence of temperature on the overall performance of pile foundations in cold regions.

ABSTRACT This study investigates the influence of rainfall patterns (RP) on the behaviour of expansive soil through a series of large-scale column experiments. The soil mass was compacted to an initial water content of 10% and dry density of either 1.0 g/cm3 or 1.3 g/cm3. The same total amount of water was introduced to the soil mass; however, over different times: a) 6 days (RP1) to mimic an extreme rainfall event and b) 14 days (RP2) to simulate a prolonged event with low daily intensity. The experimental data on changes in water content, suction, and vertical displacements revealed that the soil swell was influenced by the water influx, where RP2 was associated with a higher total swell compared to RP1. It was observed that the swell rate depended on the wetting front propagation and the initial soil density, while the swell decreased with the depth of the soil mass in the active swell zone.

ABSTRACT This study investigates the effects of pile and soil characteristics on peak particle velocity (PPV) due to pile casing driving, leading to a predictive ground vibration model. Field observations established site-specific attenuation relationships, identifying a normalized distance-to-depth ratio (D/ZP = 2.35) within permissible PPV limits (3–5 mm/s). Experimental analyses showed that increasing normalized distance (D/ES = 0.25–1.0 m/√J) and pile casing impedance (IP = 4.0–6.1 kNs/m) reduced PPV by 24.62–68.54% and 34.56–55.78%, respectively. Conversely, increasing pile depth (ZP = 0.40–0.85 m) and soil impedance (IS = 341–789 kNs/m³) raised PPV by 21.48–54.70% and 21.79–48.21%. A nonlinear regression model incorporating these parameters showed prediction errors of 17–21%, confirming accuracy. The proposed model improves upon existing approaches, providing a robust tool for ground vibration prediction and offering valuable insights for optimizing construction methodologies in urban environments.

ABSTRACT Expansive soils, when wetted, exert swell pressure on the structures built over them, often leading to damage. To quantify this additional pressure, researchers have often measured the vertical and lateral swell pressure. However, when expansive soils surround the structures in all directions, measuring the all-round swell pressure becomes more appropriate. In this context, an Isotropic – Pressure Monitoring Device (I-PMD) was employed in the present study for the measurement of all-round swell pressure for the soils C1, C2, C3, and C4 by wetting them from different initial states at constant volume conditions and was observed to be in the range of 20 kPa to 850 kPa. Also, comparative studies have been performed to comprehend the significance of all-round swell pressure measurement over conventional methods. Additionally, a relationship was proposed to predict the all-round swell pressure of the soil based on its vertical swell pressure measured by conventional methods.

ABSTRACT The lateral resistance of finned piles embedded in a two-layered sandy slope, with the top layer consisting of loose sand ( D r = 33%) followed by medium-dense sand ( D r = 61%) was examined. Comprehensive parametric studies were carried out using finite element analysis on the finned pile installed at the crest of slopes 1 V:2 h, 1 V:3 h, and 1 V:5 h. The fin efficiency was evaluated for all combinations of two-layered soil profiles with fin lengths ( L f ) covering 15%, 30%, and 45% of the pile embedment length ( L p ). The finite-element analysis shows that the deeper fins with L f = 0.45 L p were highly beneficial on the steeper slope of 1 V:2 h to enhance the lateral capacity by 35–39% relative to the regular pile. However, the efficiency of the finned pile with L f = 0.15 L p was found to be very nominal on the two-layered submerged sandy slope.

ABSTRACT This study investigates deformation and strain mechanisms of an existing tunnel in silt to tunnel failure using trapdoors in a centrifuge. The trapdoor’s width characterizes the collapsed tunnel’s diameter and the associated ground loss. Results indicated that the settlements of the greenfield and the existing tunnel generally conform to standard Gaussian curves and increase nonlinearly with ground loss. Due to soil/structure interactions, a curved soil arch develops at smaller trapdoor widths of 6 and 10 m, while a prism failure occurs in the soil at larger trapdoor widths of 12 and 16 m. The induced peak strains of the existing tunnel are 6.5 and 8.3 e-4, affected by soil arching at smaller trapdoor widths, whereas they reach 26 e-4 at larger trapdoor widths, dominated by the prism failure mechanism. Consistently, a second derivative of the Gaussian equation was adopted to describe the induced strains of the existing tunnel.

ABSTRACT This study developed theoretical equations for the estimation of the factor of safety (FS) for local instability of a wedge-shaped double body (WSDB) in soil-nail–reinforced slopes. These equations were used to perform sensitivity analysis by varying soil slope and nail parameters to assess their impact on FS. The results infer that cohesion, friction angle and slope inclination largely control the instability of WSDB between soil nails, while soil thickness, nail spacing, and nail inclination have little or no effect on FS. Finite element analysis was also performed and the results were compared with those obtained from the developed equations. It could be inferred that the FS estimated from the numerical analysis matched well with theoretical estimates when varying friction angle, slope inclination of soil and nail inclination. However, the numerical analysis portrays higher though conservative values with increase in cohesion, as compared to theoretical predictions.

ABSTRACT It is essential to develop solutions for the problem of waste generation, such as construction waste (CW) and quarry dust (QD). Reusing these materials in large-scale projects can reduce the environmental impact of irregular disposal. This paper presents an experimental study of CW and QD to partially replace a lateritic clayey soil in soil–cement. The novel use of the CW_QD mixture was also evaluated. The mixtures were prepared using soil and waste proportions of 50% for each material. The geotechnical characterization tests, unconfined compressive strength tests, indirect tensile strength tests, and resilient modulus tests were performed to evaluate the materials. Furthermore, the Brazilian method of pavement design (MeDina) was used to assess the performance of the materials. Results indicate that the partial replacement of soil with QD produces an alternative material for pavement layers considering the mechanical tests, resilient modulus, the traffic, the cracking area, and the wheel sink.

ABSTRACT Earth buildings on clayey soil can be less functional due to its low load-bearing capacity. In clayey soil with low load-bearing capability, buildings, flyovers, interchanges, and bridges fail and crack. Recently, geosynthetic reinforcements have been used to improve soil stability and bearing capacity at low cost. To maximise geosynthetic benefits, materials must be placed optimally in the foundation. Thus, this study includes small-scale laboratory footing testing to determine how the depth of the initial reinforcement layer (u), number of reinforcement layers (N), width of reinforcement (b), and vertical spacing between reinforcements (h) affect it. The results showed that geosynthetic location and loading greatly affect foundation bearing capacity. R Studio was used to calculate a regression model to determine a reinforced clay foundation’s ultimate bearing capacity using experimental results. When crucial parameters for estimating square footing ultimate bearing capacity were integrated, the model matched experimental data with 95% confidence.