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A numerical parametric study using the finite element program of PLAXIS was performed on single and double anchored sheet piles systems using different types of sandy soil backfill (loose, medium dense, and dense sand). This numerical study aimed at evaluation of the variation of maximum values of bending moments and anchor forces exerted in the sheet piles. This evaluation was affected by varying of some parameters such as the embedded depth, positions of anchor rods either the upper rod or the lower one, and the sheet pile wall flexural rigidity. For all cases, a surcharge strip load of different values covering a width of about 0.5 of the free height (h) was placed at a free distance of 0.20 h away from the wall of sheet pile. Furthermore, the effect of earth pressure due to both the own weight of backfill soil and the surcharge were considered. The study results indicated that the forces developed in the lower anchor rods are always higher than those developed in the upper anchor rods. The higher value of maximum bending moment achieved at the stiffer sheet pile wall. Finally, in the double anchored sheet pile wall, the lower values of anchor forces and that of maximum bending moments were achieved at the higher density of the soil.

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The paper studied a case of anchored sheet piles that exposed to surcharge loads at different distances from the wall. Experimental works were conducted on two different systems of single and double anchored sheet pile walls. Also, numerical simulations were performed on both systems using PLAXIS. The experimental and numerical results were compared. The comparison showed the advantages of using double anchored sheet pile instead of single anchored one. It was found that a large reduction occurred in the values of maximum bending moments in the double anchored system, in addition to a significant reduction in the values of anchor forces. This paper also produced three simplified approaches aiming to solve the statically indeterminate system of double anchored sheet pile exposed to surcharge loads placed at different distances from the sheet pile wall.

The current study implements nonlinear finite-element analysis using ANSYS15 software for the preparation of models to investigate the behavior of reinforced concrete slabs strengthened with carbon fiber-reinforced polymer (CFRP) sheets. A comparison between the results of ANSYS, experimental works, and equations of Egyptian Standing Code (ESC) was made for strengthened slabs with different sheet areas. Also, comparisons were carried out between strengthened slabs with equivalent applied areas that differ in distributions. The effects of the change of main reinforcement, compressive strength of concrete, slab thickness, and sheet thickness on strengthened slab behavior were investigated. The results of ANSYS are in good agreement with equation of ESC. The strengthening of examined slabs with CFRP sheets improves the flexural strength capacity. The distribution of CFRP sheets enhances the performance of studied slabs. The increase in compressive strength of concrete, slab thickness, and sheet thickness leads to increase in failure load magnitude of strengthened slabs. The increase in the main reinforcement increases the failure load to a certain limit. For the studied slabs, reinforcement bigger than 12 mm in diameter leads to a reduction in failure load.

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This study examines the influence of cement type, water/cement ratio, and curing process on the chloride ion permeability of concrete using ordinary Portland cement (OPC) and sulfate-resistant cement (SRC). Three concrete mixtures containing both types of cement and water/cement ratios of 0.4, 0.5, and 0.6 were investigated with two different curing methods. The cement content was 400 kg/m 3 , and the ratio of fines to aggregates was 0.5. In the first curing method, concrete specimens were cured underwater, while in the second method, specimens were cured at 22 o C and 80% relative humidity (RH) and sprayed with water twice daily for seven days. The slump, air content, and unit weight were measured as fresh concrete properties. After 28 days of curing, the compression, tension, flexure, pulse velocity, and dynamic modulus of elasticity tests for hardened concrete were carried out. In addition, titration analysis was used to determine the chloride ion permeability of concrete made with water/cement ratio of 0.4. The results reveal that cement type, water/cement ratio, and curing process greatly influence concrete's mechanical characteristics and chloride resistance.

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