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Abstract-This study investigates issues related to hydrodynamics in Lake El-Burullus and flow patterns therein. Burullus Lake is the second largest lake in the northern Egyptian coast with a total area of 410 km 2 . It was utilized Delft3D-flow module to develop a field validated hydrodynamic model. The shallow brackish Lake is mainly affected by uncontrolled creeping of development areas and growing inflow of untreated agricultural, municipal and industrial drainage water. The developed model was used to examine a potential mitigation alternative by decreasing the pollutant loads that enter the Lake i.e. diversion of existing drains. In this fashion the creation of a new development area near-by may be feasible. In addition, the effects of hydrodynamics on pollutant dispersion either from an individual drain or all drains together. The results of this study will be the base for the water quality modeling stage. Actually, this work is the first stage of an integrated Lake management. The study concluded that the developed model efficiently simulated the hydrodynamics of the Lake which can act as an effective decision support tool for improving the environmental conditions in the surroundings.

Pneumatic flow mixing method is a new land reclamation method, developed in Japan to meet the persistent lack of space. In this method dredged soft soil is mixed with a small amount of stabilizing material (such as cement) during transporting the soft soil in a pipe using compressed air to be used for land reclamation. In some cases, the soil/cement mixture is stored in temporary place for days and then transported and compacted at the required place. Basically, the cement chemical reaction starts immediately after the mixing with the soft soil and the mixture starts to gain its strength, therefore disturbing the mixture after days from the mixing influences the mixture strength. However, the soil/cement mixture is still able to gain extra strength after disturbance, transportation, and compaction. This study aims to evaluate the effect of dynamic compaction on the shear strength of disturbed cemented soft soil mixture experimentally. The mixture was fully disturbed after one week from mixing with cement. Three cement/soil ratios were used in this study under different dynamic compaction energies. Unconfined compression test was conducted at various curing times for both disturbed and non-disturbed specimens. Keywords Pneumatic flow mixing Á Stabilized soft clay Á Compaction Á Unconfined compressive strength Á Soil disturbance List of Symbols aw Cement ratio E 50 Modulus of deformation t Curing time q un Unconfined compressive strength q un_Non Unconfined compressive strength for nondisturbed cemented clay q un_Non_t Unconfined compressive strength for nondisturbed cemented clay at curing time t q un_D Unconfined compressive strength for disturbed cemented clay q un_D_T Unconfined compressive strength for disturbed cemented clay without compaction q un_D_T_t Unconfined compressive strength for disturbed cemented clay without compaction at curing time t q un_D_comp Unconfined compressive strength for compacted disturbed cemented clay q un_D_comp_t Unconfined compressive strength for compacted disturbed cemented clay at curing time i Increasing factor (i = q un_D_comp_t / q un_D_T_28) G s Average specific gravity for the specimen c w Water unit weight c t Total unit weight after curing c d Dry unit weight after curing e Void ratio after curing time R 2 Coefficient of determination

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