Applied Mechanics and Materials Vols. 773-774

Abstract: A wide range of industrial applications, on land and offshore, require the solution of time domain problems and an associated understanding of rate effects in clay soils. In recent decades many researchers have examined the correlation between shear strength of soils and variation of shear strain rate and it is generally accepted that the strength increases by 1-5% for each order of magnitude increase in shear strain rate. This paper discusses the effects of penetration rate on the penetration resistance (q_c) by using cone penetration test (CPT) test setup. The research had been conducted at RECESS and cone penetration test were used in three selected range of rate which were 0.5 cm/s, 1cm/s and 5cm/s. In addition, Mackintosh probe testhad been considered as comparison with CPT test for the unconfined compressive strength. The result shows different penetration rate influenced the soil shear strength. For the slowest rate (0.5 cm/s), the shear strength was approximately 0.15% less compared to the standard rate (2 cm/s). However, for the highest rate (5 cm/s), the shear strength was 0.22% more than the reference rate (0.5 cm/s). In conclusion, it is suggested that the RECESS clay soil influenced by the rate effect and in agreement with previous research findings.

Abstract: Electrokinetic Stabilisation (EKS) method has the potential to overcome problems on highly compressible clay. This study presents the monitoring results from an experimental study of EKS on soft clay soil. Inactive kaolinite clay, inert electrode and distilled water (DW) were used as a pure system mechanism before any chemical stabilisers are utilised for stabilisation. Therefore, this monitoring data will provide a baseline study to improve efficiency of the EKS approach for ground improvement application. An inert electrode of Electrokinetic Geosythentic (EKG) developed at the Newcastle University was utilised to apply a constant voltage gradient of 50 V/m across a soil sample of 400 mm length. The distilled waters were used at the pore electrolyte fluid compartments and supplied under zero hydraulic gradient conditions for periods of 3, 7 and 14 days. Throughout, monitoring data of electric current for all treatments were measured. Results showed that the electric current trend in this pure system was attributed to the electrochemical effects in the clay-water electrolyte system.

Abstract: This research explores the use of the seismic surface wave technique which is called as a spectral analysis of surface wave (SASW) for investigating the shallow soil profile. The testing was conducted on soft ground located at Universiti Tun Hussein Onn Malaysia (UTHM). The testing was conducted using a new developed in-house seismic surface wave testing system. An impact source using 5 kg hammer is used to generate seismic energy and four differencesarrangement of the source to receiver distances to produce soil profile. The profile of phase velocity was obtained at a depth of 0.15 m to 1.8 m were between 68 m/s and 95 m/s. The results were calibrated with the hand vane shear test which is used to obtain the undrained shear strength and thus converted empirically to seismic velocity at 45 m/s and 95 m/s. The result shows good agreement between velocity obtained from the surface wave testing system and hand vane shear test. Therefore, the new developed in-house seismic surface wave system has been proven can be used to determine the seismic velocity at shallow depth.