This paper presents a field pile load test program conducted on four 0.36 m closed-end steel pipe piles with lengths ranging between 11 and 13 m installed in fine-grained soils. Subsurface investigations with standard penetration tests and cone penetration tests with pore pressure measurements were performed at the site. Three pushed-in piezometers at incremental offsets from the piles were also installed to monitor pore water pressure changes during and after the installation of piles. Several dynamic load tests were performed at different times to observe the change in pile resistance. A static load test was also performed on one of the piles. Some load test results showed an unexpected decrease in the resistances of some piles with time. The study showed that construction activities, e.g., installation of other piles, disturbs the soil and groundwater conditions which can significantly affect the pile resistance measured during load tests. This investigation revealed that pile driving and restrikes should be scheduled such that the effect of construction activities on load tests results will be avoided or minimized.

The pile-retaining wall at Nonthaburi rural road no. 5036 was constructed using reinforced concrete piles or driven piles combined with a concrete retaining wall. The purpose of this structure was to enhance the slope stability of the canal-side road (road embankment along the canal). The damage to the driven piles occurred during the pile construction at 18 m depth below the ground surface. The resistivity survey and screw driving sounding test were employed to investigate the thickness of soft clay layers and unexpected stiff soil layers at the failure area. The field vane shear test was employed to investigate the sensitivity of the soft clay layer. Furthermore, the finite element model was analyzed to verify the failure behaviour of the road embankment during the driven pile's construction. Consequently, the investigation revealed that the subsoil in the failure area exhibited sensitivity values. The subsoil consisted of a layer of soft clay to medium stiff clay, ranging from 2-10 m below the ground surface, while the subsoil consisted of stiff clay below a depth of 10 m. The installation of the 18-m driven pile caused a disturbance in the soft sensitive clay layer above the stiff soil layer, resulting in a reduction in the strength of the soft clay and affecting the displacement of the driven pile during construction. Furthermore, the occurrence of rapid drawdown causes water seepage to continue to flow toward the canal side. This phenomenon produces active forces on the slope of the road embankment along the canal. As a result, the road embankment along the canal side can collapse due to a disturbance in the sensitive clay layer with rapid drawdown. The result was agreed with the study findings obtained by the finite element model.

Driven piles provide excellent stability to a structure by resisting lateral and vertical loads, such as those from wind and earthquakes. The impact force generated by the hammer causes the soil to compress around the pile, providing additional support and stability. In the current investigation, the overall behaviour of driven piles in multi-layered soil is assessed through finite element simulation. The soil domain comprises clay of soft consistency, loose sand, clay of medium consistency and dense sand at the bottom. The stroke applied on the top of the pile is simulated with the help of a harmonic loading system. In the study, the influence of parameters namely, pile diameter, water table depth, amplitude multiplier and soil constitutive models are examined on the behaviour of the driven pile. The results are presented in terms of settlement of the pile, excess pore water pressure phenomenon and shear stress development along the pile length. It is noticed that with the existence of a water table at the ground level, a high value of excess pore water pressure is generated at the bottom of the pile which enhances the settlement of the pile.

Integrated field and laboratory characterisation of geomaterial behaviour is critical to foundation analysis and design for a wide range of offshore and onshore infrastructure. Challenges include the need for high -quality sampling, addressing natural and induced micro -to -macro structures, and applying soil and stress states that represent both in -situ and in-service conditions. This paper draws on the Authors' recent research with stiff glacial till, dense marine sand and low -to -medium density chalk, and focuses particularly on these geomaterials' mechanical behaviour, from small strains to failure, their anisotropy and response to cyclic loading. It considers a range of in -situ techniques as well as highly instrumented monotonic and cyclic stress -path triaxial experiments and hollow cylinder apparatus tests. The outcomes are shown to have important implications for the analysis of large driven piles under monotonic -and -cyclic, axial -and -lateral loading, and the development of practical design methods. Also highlighted are the needs for approaches that integrate field observations, advanced sampling and laboratory testing, numerical and theoretical modelling.