In this research, the geotechnical properties of the soil profile in Hilla city within Babylon Governorate in the middle parts of Iraq are described. The geotechnical data at the specific sites were collected from some geotechnical investigation reports performed at some selected locations. This article is devoted to studying the distribution of soil properties (the physical and mechanical) in the horizontal and vertical directions. Moreover, a correlation between different physical and mechanical properties is performed. The correlation is executed using statistical analysis by Microsoft Excel Software (2016). From the regression results, it was found that the nature of the soil is cohesive up to 15 m under the natural ground level, and the soil will change to noncohesive. The new line in the plasticity chart has been drawn parallel to A-line especially for the investigated region, the shear strength parameters depend on the consistency of the soil and the depth, and finally, there is a direct correlation between mechanical and physical parameters. Using these correlations with some available information help to predict the value of shear strength and consolidation parameters.

Recently, Iraq has experienced more earthquakes, notice that its increased about 62% in 2024 in comparison with same period of 2023, the main aims of this study are to detect the causes and contributing factors of the earthquakes in Iraq. Natural disasters like earthquakes contributes to about 61 %. Also, they are responsible for 94% of all human deaths from natural disasters. The fundamental reasons of earthquakes occur in Iraq due to geological location, which lies on the boundary of the Arabian plate and the Iranian-Eurasian plate. There is much seismic activity in Iraq’s east and north because of the collision of the above plates. Another cause of earthquakes are faults and fractures in the earth. In addition, oil extraction and groundwater withdrawal on land also causes seismic activity in some places. Earthquakes can lead to both short and long-term risks, they can be classified into the several types as damage of structures and destruction of infrastructure like buildings, bridges, and highways can collapse, resulting in widespread damage and loss of life. Also, essential infrastructure such as power lines, water pipes, and communication lines can be cut with human fatalities and injuries. Considering the sudden increase in seismic activity in Iraq during 2024, there is a need to implement active measures to avert or mitigate earthquake hazards via using suitable foundation. This can be achieved by adopting scientific engineering, and administrative measures such as enhancing monitoring and early warning systems, improved earthquake-resilient infrastructure, community awareness and training and sustainable urban planning.

California Bearing Ratio (CBR) values are critical to the properties of granular subgrade materials and play a significant role in determining the design variables of several flexible pavement design methods. Concrete waste is considered an environmental problem in many regions of Iraq. Therefore, its removal is of significant environmental value when used to improve the properties of certain materials, such as the granular sub-base examined in this study. This research examined the impact of substituting particles measuring 19 mm to 12 mm in granular sub-base materials, class C and D, with crushed concrete waste at replacement rates of 25%, 50%, 75%, and 100% while preserving their gradation characteristics, on the CBR value. The CBR examination results showed that the most significant improvement in the CBR value was observed at a 100% replacement ratio, attaining 55.84% and 57.22% at a 1 mm penetration for the unsoaked C and D samples, respectively, and 63.32% and 48.11% for the soaked condition at a 1 mm penetration for the C and D samples, respectively. The increase in CBR was correlated with an increase in Optimum Moisture Content (OMC) and a decrease in maximum dry unit weight (γdry max), demonstrating that the percentage increase in CBR is non-linear. An increase in CBR may be helpful in the foundation base for many projects.

Lightweight concrete-filled tube (CFST) columns offer numerous benefits, such as reduced weight, enhanced resistance to buckling, improved structural performance, and the ability to endure cyclic loading. This study considered key research on the structural behavior of CFST columns, covering various topics, including lightweight concrete, methods of concrete placement within steel tubes, and CFST columns with and without shear connectors. The literature review reveals that while several researchers have explored the use of shear connectors as a load-transfer mechanism in CFST columns, there is no consensus on the design methodology for connector resistance. Shear connectors significantly improve the interlocking and bonding between the steel tube and the core concrete. However, the welding or attachment of these connectors to the steel tube can sometimes be a weak point, warranting further investigation. Based on the gaps identified in the existing literature, recommendations for future research are provided to address these limitations.