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Modeling the propagation of waves in geomechanics is an essential part of dynamic analysis. In geotechnics, the study of the interaction between the soil and the foundation is particularly interesting. In order to mimic low-speed operating types (less than 1,500 rpm), this study details the creation of a dependable and efficient approach for designing and fabricating the steel box container. When employed as a boundary, an absorbing layer drastically reduces the amount of wave reflection that occurs inside the limited region. The present effort is split into two halves. The first step is to calculate the damping layer’s damping constants, subgrade response modulus, damping ratio, shear modulus, vibration amplitude, and resonant frequency. The second section focuses on the dynamic study of the circular foundation by measuring the vibration amplitude, acceleration, velocity, and displacement caused by harmonic vibration machines. The findings demonstrate that simple material borders prevent the wave from dissipating as a consequence of reflection. Attenuation of waves is possible when the absorbing layer of energy represents semi-infinite soil. When absorbing just one layer, the vertical displacements at positions located at the box side boundary and its base decreased by 65, 63, and 67%, respectively. However, it dropped by 97, 96, and 98%, respectively, when two absorbent layers were used. On the basis of these promising results, the model results were compared with and without the absorbing layer. It would appear that the modeling of the absorbing layer, which is designed as two layers, has been satisfied for low speeds of harmonic vibration.

Several research studies have been conducted on the usage of nanoscale silica particles in concrete, based on the success of employing silica fume as an active pozzolan in concrete. The impact of several doses of nanosilicas (NpSs) in powder having a certain surface area of 160 m2/g and two particle sizes of porcelanite rock on the mechanical characteristics of lightweight porcelanite aggregate concrete was investigated. The addition of NpS particles significantly improved the workability of mixes, according to the results. The compressive strength of samples was influenced by NpS, with higher doses of NpS resulting in greater improvement. Porcelanite aggregate concrete’s compressive strength was unaffected by a modest percentage of different NpSs. NpS had an effect on the samples. Flexural strength also improved at all NpS dosages. The flexural strength of porcelanite aggregate concrete increased by a low percentage of various NpS.

Due to its large activity and raw material use, construction offers great recycled material potential. Demolition and construction waste affect the cycle. Broken window glass powder can replace self-compacting concrete due to its pozzolanic properties. This study will quantify high-strength self-compacting concrete's compatibility and mechanical characteristics (HSSCC) with varied amounts of waste glass powder. This study explored using limestone powder with 0.46 µm waste glass powder (WGP) as a filler in self-compacting concrete (SCC) mixtures. Waste glass powder (WGP) was tested as limestone filler powder replacements at 25%, 50%, 75%, and 100% by weight. Waste glass powder (WGP) was tested on compatibility with self-compacting concrete (SCC). This was done via slump flow, L-box, T500, and V-funnel testing. Furthermore, compressive, splitting tensile, and flexural strengths were to be assessed. SCC with WGP at varied replacement percentages had good flowability, passing ability, and viscosity in newly mixed concrete. Due to its filler effect and pozzolanic activity, WGP improves self-compacting concrete (SCC) compatibility and mechanical qualities. The efficiency of WGP replacement was substantially higher at 50%, resulting in a more marked influence on enhancement, particularly among those in older age groups. [ABSTRACT FROM AUTHOR]

Good water drainage from different sources is one of the most important factors that must be considered when designing subways and highways. The research aims to study and analyze the effect of heavy, medium, and low rainfall, select suitable materials to drain rainwater from the surface and vertical drains, and evaluate the rutting that appeared on the compacted surface asphalt layer. The methodology of this research includes the laboratory model (prototype model). A laboratory model consisting of typical structure layers of flexible pavement was used in this research with a 2% slope for degradations and changes in the volumetric properties and permeability of the surface and binder layers of the highway section. A wheel truck was manufactured and used for a continuous go-and-forth with the influence of three different rain intensities to identify and simulate the actual situation of highways and roads. The rainfall duration of 30 mm/min rainfall intensity was 90 minutes, and the rain intensity of 60 mm/min had a rainfall duration of 60 minutes. For the rainfall intensity of 90 mm/min, the time of rainfall was equal to 30 minutes. The results obtained from the laboratory simulation model (box model) indicated that the average quantity of infiltrated water produced by the 30mm/min rainfall intensity in the pavement structure is 36.4 % greater than the average infiltration of this water from the 60mm/min intensity and 52% higher than the 90mm/min intensity of rain. The time of surface drainage ending and the ending time of vertical drainage increases when the rain duration is long, even if the rain intensity is low. The rut depth appeared after 2816 wheel load repetitions to increase this depth by 96% after 127 days of load passage under three different rainfall intensities of a different time. The tensile strength was significantly reduced by 17.25%. The TSR values indicate that the mixtures of the surface and binder layers have good resistance to moisture damage.

The purpose of this study is to determine whether or not unsaturated gypseous soil can function well as a substrate for the foundations of carrying loads. A comprehensive program of testing was carried out with the objective of validating the geotechnical parameters and behavior of the unsaturated gypseous soils. The testing program included specific gravity, moisture content, classification tests, Proctor's compaction, relative density, and the triaxial test. Additionally, chemical analysis was performed on the samples as well. This approach was employed in a granular soil suction process to eliminate gaps of air in the soil until the soil grains held together. The sample was prepared by using a pump of vacuum with a suction process (approximately −20.0 kPa), and this method was used in the granular soil suction process. As a consequence of this, the suction prevents a specimen from collapsing when it is removed from the apparatus. The next step consisted of conducting a consolidated-undrained triaxial test on the soil. Experiments were performed on materials with a relative density of 35% and several degrees of saturation, such as normal saturation (6%), unsaturated (30, 60, 80%), and 100% saturated. It was shown that there is a reduction in the internal friction angle for the effective and total stresses is caused by an increase in the water content of the soil at any saturation degree. This occurs in both the unsaturated and saturated states of the soil. The angle of friction decreased by 80% of the natural value for both stresses, effective and total. As gypseous soil moisture increases up to the saturation degree of 60%, the soil cohesion for the total and effective stresses rises, where it increased by (220% and 125%) of the natural value for both the effective stress and the total stress, respectively, leading to an increase in the soil's shear strength (ϕ and c). After then, there was a steady weakening of the force when it reached saturation degrees of 80% and 100%, where it decreased by (44% and 47%) of the maximum value at 60% saturation degree for both the effective stress and the total stress, respectively. [ABSTRACT FROM AUTHOR]

This study shows an improvement of two types of clay soil brought from different parts of Iraq. The first soil (A) from Al - Zaafaraniya site in Baghdad governorate. The second soil (B) from Garma Ali site in the Al Basra governorate, Iraq. Soft clayey soils were treated by a combination of sulphate resistance Portland cement (PC) and Quicklime (LQ) to modify and stability. PC was added in percentages of 2,4,6,8 and 10%, as well as, LQ was added to 2 and 4%, of dry weight. Laboratory tests to determine specific gravity, Atterbergs limits and standard proctor test were conducted. Also, the main objective of this research is the concentrating on compression ratio (CR), the Rebound (Swelling) ratio (RR) and the stiffness during the modulus of elasticity (Es) for treated and natural soils procreation from consolidation test. The results from laboratory tests shows high ability on the enhancing in terms of reduction in plasticity index (greatly increased workability), reduction in compression ratio (CR), reduction in the Rebound (Swelling) ratio (RR), increase in the modulus of elasticity (Es). The change in moisture-density relationships resulting in lower maximum dry densities, higher optimum water content, and less variation of dry density from the maximum over a much wider range of water contents.

The aim of this study is to establish the effect of heavy rainfall and the chosen pavement layers on the drainage design, material selection and rutting resistance of the flexible pavement. The test in present study was started with wheel track passing without load and without rain falling on the pavement for a period of time, and it was noticed that no distress appeared on the surface of the pavement. Then, the load is gradually added by using wheel track load of 106 psi for five tests without rain falling and five other tests with gradually increasing rain fall duration and intensity. Deterioration and distresses appeared on the pavement when increasing the wheel track load to (150 psi) under high intensity rain and long term duration of rain fall. By increasing the number of days, which is 103 days of study, when the pavement is saturated, the extra amount of the water will runoff. The clogging material which caused a decrease in the water seepage, increases the time of runoff ending. The clogging materials of fine particles that get deposited on the surface of the pavement resulted by passing the wheel track loading and wear & tear of the pavement surface, and other clogging materials such as salt in the water will penetrate to the pavement and seal the voids and decrease its water seepage. The water seepage decreases by increasing number of days, so the amount of the absorbed water decreases by 89% after 71 days of testing for high rain intensity (116 ml/min.).

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