This paper presents the results of experimental investigations to predict the bearing capacity of square footing on geogrid-reinforced loose sand by performing model tests. The effects of several parameters were studied in order to study the general behavior of improving the soil by using the geogrid. These parameters include the eccentricity value, depth of first layer of reinforcement, and vertical spacing of reinforcement layers. The results of the experimental work indicated that there was an optimum reinforcement embedment depth at which the bearing capacity was the highest when single-layer reinforcement was used. The increase of (z/B) (vertical spacing of reinforcement layer/width of footing) above 1.5 has no effect on the re
... Show MoreThe bearing capacity of layered soil studies was carried out with various approaches such as experimental, theoretical, numerical, and combination of them. This work is focused on the settlement and bearing capacity of shallow foundations subjected to the vertical load placed on the surface of layered soils. The experimental part was performed by manufacturing soil cubic container (570 mm x 570 mm x 570 mm). A model square footing of width 60 mm was placed at the surface of the soil bed. The relative density of sand was constant at 60%, and the clay was prepared with a density of 19.2 (kN/m3) and water content of 14.6%. PLAXIS 3D FEM was used to simulate the experimental tests and performing a parametric study. The results showed
... Show MoreThe study is devoted to both static and earthquake response analysis of retaining structures acted upon by lateral earth pressure. Two main approaches were implemented in the analysis, namely, the Mononobe-Okabe analytical method and the numerical Finite element procedure as provided in the ready software ABAQUS with explicit dynamic method. A basic case study considered in the present work is the bridge approach retaining walls as a part of AL-Jadiriya bridge intersection to obtain the effects of the backfill and the ground water on the retaining wall response including displacement of the retaining structure in addition to the behavior of the fill material. Parametric studies were carried out to evaluate the effects of several factors
... Show MoreSoil stabilization with stone powder is a good solution for the construction of subgrade for road way and railway lines, especially under the platforms and mostly in transition zones between embankments and rigid structures, where the mechanical properties of supporting soils are very influential. Stone powder often has a unique composition which justifies the need for research to study the feasibility of using this stone powder type for ground improvement applications. This paper presents results from a comprehensive laboratory study carried out to investigate the feasibility of using stone powder for improvement of engineering properties of clays.
The stone powder contains bassanite (CaSO4. ½ H
... Show MoreObjective: The present study investigates whether the exposure to low-power diode laser induces denaturation in red blood cell (RBC) membrane protein composition, and determines the irradiation time for when denaturation of membrane protein process begins. Background: A low-energy laser has been used extensively in medical applications. Several studies indicated significant positive effects of laser therapy on biological systems. In contrast, other studies reported that laser induced unwanted changes in cell structure and biological systems. The present work studied the effect of irradiation time of low-power diode laser on the structure of membrane proteins of human RBCs. Materials and methods: The RBC suspension was divided into five equa
... Show MoreTuberculosis status as the second leading causes of significant morbidity and mortality from an infectious disease worldwide, after human immunodeficiency virus (HIV). Sample collection was conducted at the Institute of Chest and Respiratory Diseases/Baghdad Medical City in Baghdad. The collection interval was from August to October 2014, 629 suspected TB patients were examined during this period. The results revealed among total 629 specimens, 56 (8.9%) of the specimens were positive by direct examination and 573 (91.1%) negative specimens by smear microscopy. Fifty six DNA samples were extracted from positive ZN smears of sputum specimens and 40 samples from healthy persons (as control) were subjected to molecular diagnosis by real tim
... Show MoreTrue random number generators are essential components for communications to be conconfidentially secured. In this paper a new method is proposed to generate random sequences of numbers based on the difference of the arrival times of photons detected in a coincidence window between two single-photon counting modules