Potential use of residual soil and geosynthetic

Rainfall-induced slope failures frequently occur in residual soil slopes in tropical regions. Previous research works indicated that the main cause of slope failure in residual soil slopes is rainfall infiltration. The infiltrating water decreases matric suction in the soil and consequently reduces shear strength of the residual soil slopes. One of the possible preventive measures for the rainfall-induced slope failures is the use of a soil cover to minimize water infiltration into the slope. Previous research works showed that a capillary barrier system could be used as a soil cover to minimize rainfall infiltration. A capillary barrier is a soil cover consisting of a fine-grained soil layer overlying a coarse-grained soil layer. In this study, the use of a local residual soil derived from Bukit Timah Granite as the finegrained layer in a capillary barrier system was investigated.Doctor of Philosophy (CEE

Use of instantaneous profile and statistical methods to determine permeability functions of unsaturated soils

This paper presents the determination of permeability functions by direct and indirect methods. The direct method used in this study was the instantaneous profile method, while the indirect method used was the statistical method. The instantaneous profile method was adopted to calculate permeability functions of residual soils used in laboratory slope models. Pore-water pressure measured using tensiometers along the slope models and independently measured soil-water characteristic curves (SWCCs) were used for the instantaneous profile calculation. To obtain a continuous permeability function, the instantaneous profile results were then fitted using the statistical method.Accepted versio

The design of Subsea foundations subject to general cyclic loading using a massively scalable web based application

Subsea developments require the design of large numbers of shallow skirted foundations to support structures such as manifolds, pipeline and umbilical terminations and in-line tees. Safe and economic design relies on the accurate assessment of foundation capacity against thousands of load-combinations. Performing these design calculations is a significant computational task. The objective of this paper is to demonstrate how new developments in cloud computing can be utilized to optimize foundation design.Engineering design is no longer limited by computing power thanks to the introduction of low-cost on-demand cloud computing platforms. This paper describes a massively scalable cloud based application for rapidly assessing the vertical-horizontal-moment-torsional capacity of shallow skirted foundations against thousands of cyclic load case combinations that arise from numerous environmental and service conditions. The detrimental effect of cyclic loading and the beneficial effect of consolidation on soil strength are incorporated within a single workflow.It is shown that cloud technologies can radically improve traditional engineering design procedures, allowing engineers to focus on the innovative and creative aspects of their work, while the tasks of preparing, executing and documenting calculations become near instantaneous and more easily assessed for quality assurance. More critically, the technology allows rapid and rigorous optimization of the foundation dimensions to achieve the most cost-effective solution that satisfies all load cases. The scalability of the application allows multiple users to run large numbers of calculations simultaneously across a virtually unlimited number of computer nodes. The system can be accessed through a standard web browser and can run simulations on any internet-connected device. Results are saved in the cloud and can be accessed anywhere and shared among colleagues, enhancing collaboration and quality assurance. The approach results in demonstrably superior design outcomes, achieved more quickly.This paper presents what is believed to be the world's first web based application for shallow foundation design that exploits the availability of low cost on-demand cloud computing services. The paper will explain some of the challenges in implementing such a system and provide examples. We believe this type of technology represents the future for geotechnical design work, providing better design in a more efficient manner.<br/