hanaa shihab humadi alghrubawi

Retaining walls are typical geotechnical engineering applications analyzed extensively in the literature. However, the optimal design of these walls is still unsolved due to the optimization problem's complexity and the unrecognized best solver that can be used. Most similar works present a single optimizer for this problem. This work used six metaheuristics to formulate and solve the optimal gravity retaining wall problem design. The comparative study was achieved among particle swarm optimization, dynamic differential annealed optimization, artificial bee colony, fertilization optimization algorithm, grey wolf optimizer, and whale optimization algorithm. The problem and its results were discussed in detail within the respective sections.

Reactive Powder Concrete (RPC) is a significant technological advancement in the concrete construction field. The unique properties of RPC, such as its high compressive strength, tensile strength, and flexural strength, make it ideal for use in construction applications that need high strength and durability, such as bridge piles, pre-stressed beams, and underground structures (mining facilities, basement foundation). The experimental study was conducted to evaluate the mechanical properties of building materials. The trial program tested sixteen specimens to examine the effects of the volumetric ratios of steel fiber and silica fume on the mechanical characteristics of RPC mixtures. The volumetric ratios of steel fiber and silica fume were considered when analyzing the mechanical properties of the RPC mixtures. The impact of the volumetric ratio of steel fibers was investigated by investigating six mixtures with varying ratios of (Vf) from 0% to 1% and 2% by volume fraction of concrete that adding steel fibers to RPC provides a significant increase in compressive strength measurements, growing Vf from 0% to 1% and 2% leading to an acquired rise in compressive strength by 22.71% and 35.05% respectively. The silica fume ratio (SF) also increased from 15% to 20% and 25% the inclusion of silica fume only led to a modest increase in the compressive strength of RPC by 5.35% and 9.29% when the silica fume ratio was increased from 15% to 20% and 25%, respectively. The results of the experimental tests showed improvements in the hardened properties, including compressive strength, splitting tensile strength, and modulus of elasticity.

It is a significant issue to analyze and understand the pile’s behavior as well as to predict the piles’ capacity exposed to uplifting load when designing a foundation. Experimental model tests have been conducted for a single pile embedded in cohesionless soil and subjected to uplift force. The experimental tests were performed using a vertical open-ended steel pipe piles with circular cross-sectional area an outer diameter of 50 mm in steel soil box (0.5*0.5) with four different height (0.30, 0.50 and two with 0.40 m). The tested piles have been embedment with penetration ratios (PR=L/D) of 10. Three different densities (25%, 50% and 75%) have been used to perform the tests. In addition three tests have been made with relative density of 50% to investigate the function the developed soil column inside the pile (soil plug) during installation. results revealed that the behavior of single piles depends mainly on soil density and the ultimate pull-out capacity of the pile increases with the increasing of the soil relative density and used the data from this tests to presented formula to estimate the IFR and takes the soil state parameter as a qualitative variable. The results showed also that the removing of soil’s plugging decreases the pile’s pull-out capacity by about 85%. Whilst, using of closed-end or filled with concrete give higher capacity than that of open-end pipe pile by about 33% and 87% respectively.

It is a significant issue to analyze and understand the pile’s behavior as well as to predict the piles’ capacity exposed to uplifting load when designing a foundation. Experimental model tests have been conducted for a single pile embedded in cohesionless soil and subjected to uplift force. The experimental tests were performed using a vertical open-ended steel pipe piles with circular cross-sectional area an outer diameter of 50 mm in steel soil box (0.5*0.5) with four different height (0.30, 0.50 and two with 0.40 m). The tested piles have been embedment with penetration ratios (PR=L/D) of 10. Three different densities (25%, 50% and 75%) have been used to perform the tests. In addition three tests have been made with relative density of 50% to investigate the function the developed soil column inside the pile (soil plug) during installation. results revealed that the behavior of single piles depends mainly on soil density and the ultimate pull-out capacity of the pile increases with the increasing of the soil relative density and used the data from this tests to presented formula to estimate the IFR and takes the soil state parameter as a qualitative variable. The results showed also that the removing of soil’s plugging decreases the pile’s pull-out capacity by about 85%. Whilst, using of closed-end or filled with concrete give higher capacity than that of open-end pipe pile by about 33% and 87% respectively.

Predicting of piles capacity and their behavior is always an important and serious problem for a safe geotechnical engineering design. In the present study, experimental model tests have been conducted on a single steel pipe piles driven in sandy soil and subjected to pull-out force. The experimental tests were conducted on vertical open-ended piles with circular and square cross-sectional area and three various diameters 3 cm, 4 cm and 5 cm in a steel soil box have been used. The tested pile's model has embedment with three penetration ratios (PR=L/D) of 10, 15 and 20. All tests were done in medium density soil (Dr = 50%) with open ended pipe pile to study the effect of pile geometry on pile behavior, and three other tests were conducted on the 5cm diameter and 10 penetration ratio in medium soil density to study the importance of addition of separating wall. The study discovered that the capacity of single piles with circle cross-section area under pull-out force increasing by 211% and 458% with the increasing of pile diameter (width) from 3cm to 4cm and 5cm respectively, and increasing by 210%, 448% and by 112%, 288%. Also, by 79% and 211% with increasing penetrating ratio (PR) from 10 to 15 and 20 for diameters 3cm, 4cm and 5cm respectively, with respect to reference pile. And the same behavior for square cross-section pipe pile, when the pull- out capacity increasing with the increase of pile width and penetration ratio due to the increasing in the friction area. Besides that, It was also found that the separation walls increased the coefficient of lateral pressure in addition to the friction area. At the same time, there are an optimum number of separation walls that can be used to increase the pile pull-out capacity and that when using three separation walls.