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This paper discusses on the compaction effect to the hydraulic conductivity performance for the sedimentary residual soil mixed bentonite. This mixture is proposed as a barrier material in landfill area and may possibly potential materials for use as compacted soil liners in landfills for leachate protection. A laboratories series was conducted to evaluate the effectiveness of compaction characteristics on sedimentary residual soil mixed with different percentage of bentonite (5%, 10% and 15%). The sedimentary residual soil sample was used in this study and was collected in sedimentary residual formation area in Salak Tinggi, Malaysia and named as Salak Tinggi soil. The mixed samples were compacted at three different compaction effort with different energy to determine the maximum dry density (MDD) and optimum moisture content (OMC). Then, the permeability test to determine the hydraulic conductivity (k) was conducted at MDD condition at every compaction effort at effective stress of 100 kPa. The results show that the MDD value were slightly low for the entire soil sample mixed with bentonite at all compaction energy level. Instead it shows all the three different compaction efforts applied to the mixed soil samples with bentonite yielded hydraulic conductivity less (k ≤ 1x10−9m/s). In fact, the increment of bentonite content also resulted in lower of MDD value and hydraulic conductivity value. However, MDD values were found to be higher for mixed soil when compacted with high compaction effort. The results of hydraulic conductivity tests demonstrated that hydraulic conductivity, k ≤ 1x10−9m/s can be achieved just by using lower compaction energy for the soil mix with bentonite. Instead it considered as suitable materials for liner due to the hydraulic requirement for soil barrier, k ≤ 1x10−9m/s. This finding show that compaction efforts play an important role for workability of the mixtures and significantly to be used as compacted of soil liner materials.

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This paper reports a numerical and experimental investigation conducted to study the thermal signature of buried landmines on soil surface. A finite-volume-based numerical model was developed to solve the unsteady three-dimensional heat transport equation in dry homogeneous soil with a buried mine. Numerical predictions of soil thermal response were validated by comparison with published analytical and numerical values in addition to data obtained experimentally. Experiments were performed inside an environmental chamber and soil temperatures were measured during cooling, using two measurement techniques, after exposing the soil surface to a radiant heat flux for a specified period. In the first technique, the temporal variation of the surface and internal soil temperatures were recorded using thermocouples. In the second technique, the soil surface temperature was measured using an infrared camera that revealed the thermal signature of the mine. The transient temperature profiles generated numerically agreed with measurements, and the difference between predicted and measured values was less than 0.3°C at both the soil surface and in depth. The accurate matching of numerical and IR images at the surfaces was found to strongly depend on the use of a smaller soil thermal conductivity at the surface than at greater depths. The numerical model was used to predict the dependence of the peak thermal contrast on time, depth, and heating period. The thermographic analysis, when combined with numerical predictions, holds promise as a method for detecting shallowly buried land mines.

This study presents the findings of a 3D finite element modeling on the performance of a single pile under various slenderness ratios (25, 50, 75, 100). These percentages were assigned to cover the most commonly configuration used in such kind of piles. The effect of the soil condition (dry and saturated) on the pile response was also investigated. The pile was modeled as a linear elastic, the surrounded dry soil layers were simulated by adopting a modified Mohr-Coulomb model, and the saturated soil layers were simulated by the modified UBCSAND model. The soil-pile interaction was represented by interface elements with a reduction factor (R) of 0.6 in the loose sand layer and 0.7 in the dense sand layer. The study was compared with the findings of 1g shaking table tests which were performed with a slenderness ratio of 25. In the validation case, there was a clear correlation between the laboratory findings and the numerical analyses. It was observed that the failure mechanism is influenced by the soil condition and the slenderness ratio to some extent. Under the dry soil condition, no base pile deformation was observed; However, tip pile movement was observed under the saturated soil condition with pile slenderness ratios of 25 and 50. The findings of this study are also aimed to include an approximation of the long-term deformations at the ground surface which has experienced shaking.