Nor Zurairahetty Mohd Yunus

Stabilization of Marine Clay by Biomass Silica (Non-Traditional) Stabilizers

The presence of marine clay in Iskandar Malaysia Region, Nusajaya had caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of Biomass Silica (BS), one of the commercial brands namely “SH-85” to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the Atterberg limits and Unconfined Compressive Strength (UCS) for treated and untreated of marine clay soils. The proportions of BS added were 3, 6, 9, 12 and 15% and tested at 0, 3, 7 and 28 days curing periods. The results shows that the Plasticity Index (PI) was reduce with increment of BS content. While, an addition of BS content increase in strength treated soils 60 times more than untreated soils, which is gain in early 7 curing days period. This finding indicates the BS is a suitable stabilizer for the marine clay to become strong foundation for construction of road and building.

PERFORMANCE OF LIME-TREATED MARINE CLAY ON STRENGTH AND COMPRESSIBILITY CHRACTERISTICS

The presence of marine clay in Iskandar Malaysia Region, Nusajaya has caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of lime to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the physical and engineering properties with and without the addition of lime. The proportions of hydrated lime added are 3%, 6% and 9% to the untreated marine clay and tested at 7 and 28 days curing periods. Results show an increase in strength with increasing lime content. In addition, strength also increases significantly as early as 7 curing days and continues for 28 curing days. In agreement with the strength tests, compression characteristics improved with increasing lime content and as time prolonged. Hence, lime is successful and considered effective to improve the strength and compressibility behavior of Marine clay.

Bearing Capacity of Circular Footing on Sand Deposit

Bearing capacity and settlement are two important parameters in geotechnical engineering. The bearing capacity of circular foundations on sandy soils is important to geotechnical practicing engineers. Design of foundations includes soil parameters and bearing capacity of foundation. This paper presents the results of laboratory experimental model tests of circular footings supported on sand deposit under static load. The finite element software Abaqus is used to compare the results. The effects of the relative density of the sand (30%, 50%, and 70%) and the diameter of circular footing (75 mm and 100 mm) are investigated. It can be concluded that the experimental test results fit quite well with the results of numerical method.

Experimental and numerical study on softening and pinching effects of reinforced concrete frame

The response analysis of reinforced concrete (RC) structures subjected to strong earthquake motions requires material models that are able to simulate cyclic deformation and damage realistically. This paper presents the results of a study of pinching and softening behaviour in an RC frame subjected to cyclic loading. The experiment was conducted on a full-scale RC frame at Indian Institute of Technology Roorkee in India. The hysteretic curve representing the response of the frame was generated. Finite element analyses were performed to predict the response of the frame under cyclic loading both before and after the test using different computer codes, ABAQUS and OpenSees. Although the experiment was conducted using load control, the finite element simulations were performed using displacement control. The result from both models are compared to the experiment and to each other and a detailed discussion is provided on the modelling capabilities of the two software in capturing the pinching and softening behaviour observed in the test.