One of the fundamental section of sustainable improvement in river basin systems and has multifunctional targets is river restoration. The targets of river restoration are to minimize the physical degradation and recover river elegance value, pollution manage and good ecosystem with biodiversity. River restoration is a multidisciplinary task in which engineer, hydrologist, geologist and ecologist can work together to enhance river environment. In decades ago, Malaysia was exposed to fast evolution and subsequently extreme flooding has happened especially in urban territories. In order to minimize flood damage, the flood mitigation measures were taken and channel improvement is mainly utilized for this goal. Due to the insufficient available river reserve and perhaps the absence of environmental awareness, previously, the consultant engineers usually advised a wider and deeper rectangular concrete river channel to mitigate the flood damage. The replacement of the natural river channel with a concrete channel outcomes are increased physical degradation and lowering of aesthetic and recreational values of rivers. Lately, there is a strong confirmation to take into account the environmental effect in rivers canalizing. Malaysian experience in restoration of the urban river will be focused on in this study, with a particular emphasis on environmentally friendly materials utilized for flood mitigation goals.

Stone columns in soft soil improve bearing capacity because they are stiffer than the material which they replace, and compacted stone columns produce shearing resistances which provide vertical support for overlying structures or embankments. Also stone columns accelerate the consolidation in the native surrounding soil and improve the load settlement characteristics of foundation. In this paper, the finite element method is utilized as a tool for carrying out analyses of stone column-soil systems under different conditions. A trial is made to improve the behaviour of stone column by encasing the stone column with geogrid as reinforcement material. The program CRISP-2D is used in the analysis of problems. The program allows prediction to be made of soil deformations considering Mohr-Coulomb failure criterion for elastic-plastic soil behaviour. A parametric study is carried out to investigate the behaviour of standard and encased floating stone columns in different conditions. Different parameters were studied to show their effect on the bearing improvement and settlement reduction of the stone column. These include the length to diameter ratio (L/d), shear strength of the surrounding soil and, the area replacement ratio (a s ) and others. It was found that the maximum effective length to diameter (L/d) ratio is between (7-8) for Cu, between (20-40) kPa and between (10-11) for Cu = 10 kPa for ordinary floating stone columns while the effective (L/d) ratio is between (7-8) for encased floating stone columns. The increase in the area replacement ratio increases the bearing improvement ratio for encased floating stone columns especially when the area replacement ratio is greater than (0.25). The geogrid encasement of stone column greatly decreases the lateral displacement compared with ordinary stone column.

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Recently the numerical modeling using finite element method is take into account as a very effective tool to investigate the desired behavior of structures in geotechnical engineering. Earth dams are a water retention structures that are normally wide constructed around the world due to its significant features. These structures may be failed due to exposure to an earthquake and this will result in disaster. The main objective of this study is to assess the slope stability and the seismic response of an earthen dam. Since the matter of seismic response is still have a considerable lack of information for earth dams as a unique structure. Hemren zoned earth dam that is located in Diyala governorate, northeast of Iraq that considered as an active seismic zone has been considered as case study. Numerical modeling has been done in this study using Geo studio software. Factor of safety was calculated with different water levels in order to evaluate the dam safety with different operation water level. The excited earthquake is Elcentro while three values of peak ground acceleration were used which are 0.2, 0.25 and 0.3 g and the duration time is scaled to 10 seconds. In addition, three key points (at the core, the shell and the foundation) that represent the dam construction material are used to evaluate the dynamic response within the dam body. The results revealed that the factor of safety is increased when the water level is increase, but in the increasing in the magnitude of factor of safety with water depths of (10 and 15) m was more than the other depth. The zone of the dam core shows a negative pore water pressure value. That leads to an increasing in effective stress at the core of the dam.