Impact of slopes on the lateral resistance of steel piles

A soldier pile and lagging wall is one of the most common types of retaining wall. Solider pile walls develop lateral resistance through the stiffness of the piles and the passive resistance of the soil acting upon the embedded portion of the piles. Ground anchors can also be used when additional lateral resistance is required. Using Broms’ methods, a parametric study was completed to investigate the performance of laterally loaded short and long steel piles installed in a variety of cohesive and cohesionless soils. The results were compared to those generated using RocScience finite element software. RocScience software was then used to evaluate the lateral resistance of piles installed at various distances from the crest of a 2:1 slope. Finally, two soldier pile walls, to be installed within a sloping railway embankment, were designed.

Impact of slopes on the lateral resistance of steel piles

A soldier pile and lagging wall is one of the most common types of retaining wall. Solider pile walls develop lateral resistance through the stiffness of the piles and the passive resistance of the soil acting upon the embedded portion of the piles. Ground anchors can also be used when additional lateral resistance is required. Using Broms’ methods, a parametric study was completed to investigate the performance of laterally loaded short and long steel piles installed in a variety of cohesive and cohesionless soils. The results were compared to those generated using RocScience finite element software. RocScience software was then used to evaluate the lateral resistance of piles installed at various distances from the crest of a 2:1 slope. Finally, two soldier pile walls, to be installed within a sloping railway embankment, were designed.

Optimal Design of Cantilever Soldier Pile Retaining Walls Embedded in Frictional Soils with Harmony Search Algorithm

In this paper, the design of cantilever soldier pile retaining walls embedded in frictional soils is investigated within the insight of an optimization algorithm to acquire cost and dimension equilibrium by ensuring both geotechnical and structural requirements simultaneously. Multivariate parametric analyses with different fictionalized cases are performed to evaluate the effects of design variants and to compare the effectiveness of the preference of optimization solutions rather than detailed advanced modeling software. The harmony search algorithm is used to conduct parametrical analyses to take into consideration the effects of the change of excavation depth, shear strength angle, and unit weight of soil, external loading condition, and coefficient of soil reaction. The embedment depth and diameter of the soldier pile are searched as design dimensions, and the total cost of a cantilever soldier pile wall is calculated as an objective function. The design dimension results of the parametric optimization analysis are used to perform finite element analysis with a well-known commercial geotechnical analysis software. The results of optimization and finite element solutions are compared with the use of maximum bending moment, factor of safety, and pivot point location values. As the consequence of the study, the influence rates of design variants are procured, and the effectiveness of the usage of optimization algorithms for both cost and dimensional equilibrium is presented.

Three-dimensional analysis of anchored wall with concrete bearing pads

Purpose Anchorage with concrete bearing pad is commonly used in Iran for stabilization of excavations because of the ease of construction, less costs and less time consumption than the soldier pile method. In this method, a wall facing which includes the concrete bearing pads at the location of the anchors and a shotcrete layer between the bearing pads is constructed parallel to the excavation operation similar to the nailing method. Design/methodology/approach In this paper, using the finite element software Abaqus, a three-dimensional model of the above-mentioned type of wall is constructed, and the effect of spacing and size of bearing pads on the wall behavior is discussed. Findings According to the obtained results, the size of the concrete bearing pads has little effect on wall deformations, but the internal forces and bending moments developed in the shotcrete layer between the bearing pads are greatly influenced by the bearing pads dimensions and spacing. Originality/value Owing to the discrete elements of the wall facing, the behavior of this system is completely three-dimensional.

Thermal response of energy soldier pile walls

Utilising foundation systems as heat exchangers has received significant public interest worldwide, as these energy geo-structures can constitute a clean, renewable, and economical solution for space heating and cooling. Despite their potential, the thermal performance of energy retaining walls, especially soldier pile walls, has not been sufficiently studied and understood and thus further research is required. This work utilises the first ever energy soldier pile wall in the currently under-construction Melbourne CBD North metro station as a case study. A section of this wall has been instrumented and monitored by the University of Melbourne. Full scale thermal response tests (TRTs) have been conducted on a single thermo-active soldier pile at two different excavation levels. Thermal response testing field data results are presented in terms of mean fluid temperatures and further analysed to show the potential impact of the excavation level on the structure’s thermal performance. To further explore this impact of excavation depth (or pile embedment depth) and the long-term thermal performance of energy pile walls, a detailed 3D finite element numerical model is developed in COMSOL Multiphysics and validated against the field-testing results. The simulation suggests that thermally activating all the soldier piles in the station can provide enough energy to fulfil the heating and cooling demand of the station and to satisfy partial heating demand to the surrounding buildings. Furthermore, results suggest that current energy pile design approaches may be adapted for designing energy pile walls.