Journal of Engineering

This study investigates the effect of seismic loading on the variation of pore water pressure during pile pull-out tests in sandy soils. An experimental model was conducted using a pile model with a length-to-diameter ratio (L/D) of 25, installed in a laminar shear box containing different saturation soil densities (loose and dense sand). Two pore water pressure transducers were placed near the middle and bottom of the pile model to evaluate the pore water pressure during pull-out tests. Seismic loading was applied using a uniaxial shaking table device, while pull-out tests were conducted using a pull-out device. The results showed that the variation of pore water pressure near the bottom of the pile was greater than the variation near the middle of the pile in all tests. Additionally, the variation of pore water pressure after applying seismic loading was greater than the variation before applying seismic loading, both near the middle and bottom of the pile, and in both loose and dense sand. The variation of pore water pressure after applying seismic loading and uplift force was less than the variation after applying seismic loading in loose sand at the middle and bottom of the pile.

This paper reviews the reuse of recycled plastic waste (sustainable plastic) to produce environmentally friendly concrete (green concrete). The review summarizes various studies on the percentage of plastic replacement from the aggregate and its effects on the fresh properties of concrete, such as workability, and the hardening properties, including dry density, compressive strength, tensile strength, and flexural strength. The research highlights the importance of using recycled plastic waste in concrete to reduce environmental pollution and promote sustainable construction practices.

Kriging, a geostatistical technique, has been used for many years to evaluate groundwater quality. The best estimation data for unsampled points were determined by using this method depending on measured variables for an area1. The groundwater contaminants assessment worldwide was found through many kriging methods. The present paper shows a review of the most known methods of kriging that were used in estimating and mapping the groundwater quality1. Indicator kriging, simple kriging, cokriging, ordinary kriging, disjunctive kriging, and lognormal kriging are the most used techniques. In addition, the concept of the disjunctive kriging method was explained in this work to be easily understood1

Jet grouting is a widely applied soil improvement technique suitable for various geotechnical problems, including improving bearing capacity, decreasing settlement, forming seals, and stabilizing slopes. This paper discusses the effect of the water-cement ratio on the physical and mechanical characteristics of soilcrete. In the laboratory, sandy soil was mixed with cement grout with water-cement ratios ranging from 0.7:1 to 1.4:1. To evaluate the characteristics of soilcrete, 96 specimens were prepared and tested at different curing times. The results indicate that the Uniaxial Compressive Strength (UCS) of soilcrete decreases with increasing the water-cement ratio. The UCS of soilcrete with a water-cement ratio of 0.7 is higher by approximately 237% compared to a ratio of 1.4 at 28 days. The evolution of UCS is proportional to the logarithm of the curing time. The ratio between the modulus of elasticity (Etg50) to the maximum UCS varies from 113 to 175. As the water-cement ratio increases, the dry density of soilcrete decreases, resulting in a decrease in UCS.

The Al-Chibayish Marsh (CM) is a significant part of the Central Marshes area, covering 1050 km². The water quality of these marshes suffers from salt accumulation due to intensive dam construction, limited water supply, climate change impacts, and the absence of outlet flow, especially during low flow periods1. This research aims to assess and improve the hydraulic behavior and water quality of the marshes and define the best locations for outlet drains. Field measurements and laboratory tests were conducted in November 2020 and February 2021 to define the TDS concentrations at nine different locations1. Water samples were examined for physical and chemical properties such as pH, electrical conductivity, water temperature, dissolved oxygen, and turbidity. Hydrodynamic and water quality simulations were conducted using SMS-RMA2 and RMA4 software to specify water depths, velocity variations, and salt content distribution1. The results showed that the use of these outlets would significantly improve water quality.

Shatt Al-Arab River in Al Basrah, Iraq, has recently recorded massive levels of TDS values (Total Dissolved Solids) in the water due to reduced fresh water discharge from sources, causing the river to become salinized due to salt wedge intrusion. Therefore, a block dam in the south reach is required to prevent salt intrusion. The main objective of this research is to simulate the hydraulic impact of a suggested barrage in Ras Al Besha on the Shatt Al-Arab River. The HEC-RAS (5.0.7) model was used to develop a one-dimensional unsteady model to understand the proposed barrage's influence on river behavior. The daily discharges of the Tigris River provided as the upstream boundary conditions, while the hourly water levels of the Shatt Al-Arab River provided as the downstream boundary conditions. The model was initially run based on daily discharges in August 2018 and March 2020 for the model's calibration and verification. Then, a model was run with a proposed barrage, and four cases of discharge were chosen: low and moderate discharge equal to 20-50-100 and 250 m³/s with an adopted spring tide cycle. The operation scenarios were examined under the influence of three cases of barrage gates (fully opened, 50% open, and programmed opening). The results indicate that the investigated discharges will cause significant problems in navigation depths, especially in the case of the programming of gates opening where the stages drop range between 2.01-3.3m compared to the normal case. Furthermore, the velocity indicators show that the significant reduction in velocity upstream the barrage led to more sedimentation in the river reach.