Papers by Nadher Al-Baghdadi
Engineering, Technology & Applied Science Research
In the present research work, a one-dimension finite element model has been developed to simulate... more In the present research work, a one-dimension finite element model has been developed to simulate both compression and tension types of grouted ground anchors. The steel tendon-grout interface has been modeled by using the local bond-slip model, while the soil-grout interface has been modeled with a series of perfectly elastic plastic springs. The verification of the proposed one-dimension finite element model has been made by comparison of the model results with a three-dimension finite element model developed by commercial finite element software PLAXIS, and with the results of field tests of tension-type grouted ground anchor. A parametric study has been made to study the load-transfer mechanism for both types of anchors, compression, and tension. The compression-type anchor exhibits less displacement than the tension one under the same applied load. The developed strain in the grouted body of the compression-type anchor is much smaller than the tension-type one, regardless of th...
Open Engineering
This article presents test results documentation for four grouted ground anchors embedded in sand... more This article presents test results documentation for four grouted ground anchors embedded in sandy soil. Three anchors were trial, while one was a working anchor. One trial anchor is instrumented with eight resistance-type strain gauges glued on the corrugated pipe and embedded within the grouted body. An acceptance test was made for all anchors to determine the working load. Acceptance criteria suggested by the Post-Tensioning Institute were applied, and the working anchor did not pass the creep criterion, so it was taken out of service. The strain measurements indicated that the compression stresses were generated along the free length, while the tension stresses were generated along the bonded length. The transition point, which is the point with zero axial stress within the grouted body, was located at a distance of 10–12% of the bonded length, measured from the proximal end of the bonded length. The skin friction distribution along the grouted body was nonuniform, and it had a ...
Kufa journal of Engineering, 2014
The piled raft is a geotechnical composite construction consisting of three elements: piles,raft ... more The piled raft is a geotechnical composite construction consisting of three elements: piles,raft and soil. It is suitable as a foundation for large buildings. This paper presents an analysis of piled raft foundation, included material nonlinearity and soil structure interaction. An efficient computer program in FORTRAN 9Ois developed for this analysis. A 20 node disoparametric brick element has been used to model pile, raft, soil and interface materials. Thin layer interface element has been used to model the contact zone between the pile and soil, and between raft and soil. The behavior of the piled raft material is simulated by using a linear elastic model. However, the behavior of soil and interface materials is simulated by an elasto-plastic model by the use of Mohr Coulomb failure criterion. Some of the variables of piled-raft system, related to settlement and differential settlement in sandy soil, have been studied, where the length of piles and distance between piles an effec...
Journal of University of Babylon, 2016
The present paper submits a set geotechnical maps for the area of An-Najaf city, by using contour... more The present paper submits a set geotechnical maps for the area of An-Najaf city, by using contour lines to represent the different geotechnical properties of the soil. The present research work is very important step toward preparing a geotechnical database for this region, to complete the geotechnical database over all the country, (Iraq). Using such a database is very important in geotechincal investigation, reconnaissance phase, of construction projects. Within this phase of site investigation, numbers, depths and locations of the boreholes needed, will be determined. A well known commercial software (SURFER 11), was used to produce the all the contour maps of geotechnical properties presented herein. A forty nine (49) contour maps were produced to cover the variations, within the geotechnical properties of the soil, to produce realistic description to these soil properties. Both Google maps and Universal Transverse Mercator coordinate system (UTM) have been used in the contour maps for easy use.
Kufa journal of Engineering, 2014
The basic concept of soil nailing is to reinforce and strengthen the existing round by installing... more The basic concept of soil nailing is to reinforce and strengthen the existing round by installing closely spaced steel bars, called “Nails”, into a slope as construction proceeds from “top-down”. This process creates a reinforced section that is in itself stable and able to retain the ground behind it. Soil nailing technique is used to support new very steep cuts with advantage of strengthening the slope with excessive earth works to provide construction access and working associated with commonly used retaining systems. In the present research work a parametric study has been made using commercial computer program “Slide 6“, which utilize different methods for solving slope stability problem, Bishop method has been used herein to analyze un nailed and nailed slopes with granular soil, different slope heights and angles have been considered. Some of nails parameters have been studied here in, positions of nail, length of nail, angle of nail inclination, and nail spacing. The optimum...
Kufa journal of Engineering, 2016
The research presents a numerical study of the interaction between single cavity and adjacent pil... more The research presents a numerical study of the interaction between single cavity and adjacent pile in homogenous sandy soil by utilizing an efficient finite element formulation. A square cross sectional concrete pile, with (9) m length and (0.6) m width, has been used. The interface layer between pile and surrounding soil was represented by thin layer element. The research results indicate that, in the direction perpendicular to the direction of applied load, where the ratio between the distance from the cavity to the pile and cavity length (measured in the same direction), is equal or more than (1.7) the effect of cavity can be neglected. While the values of the maximum bending moment decrease with increasing of the above mentioned ratio, and it became constant when the ratio ≥ (2.0). The deformations around cavity increases with increasing lateral load and decreasing the above mentioned ratio, particularly in the nearest side of pile and these deformations are constant when the r...
The present paper submits a set geotechnical maps for the area of An-Najaf city, by using contour... more The present paper submits a set geotechnical maps for the area of An-Najaf city, by using contour lines to represent the different geotechnical properties of the soil. The present research work is very important step toward preparing a geotechnical database for this region, to complete the geotechnical database over all the country, (Iraq). Using such a database is very important in geotechincal investigation, reconnaissance phase, of construction projects. Within this phase of site investigation, numbers, depths and locations of the boreholes needed, will be determined. A well known commercial software (SURFER 11), was used to produce the all the contour maps of geotechnical properties presented herein. A forty nine (49) contour maps were produced to cover the variations, within the geotechnical properties of the soil, to produce realistic description to these soil properties. Both Google maps and Universal Transverse Mercator coordinate system (UTM) have been used in the contour maps for easy use.
The research presents a numerical study of the interaction between single cavity and adjacent pil... more The research presents a numerical study of the interaction between single cavity and adjacent pile in homogenous sandy soil by utilizing an efficient finite element formulation. A square cross sectional concrete pile, with (9) m length and (0.6) m width, has been used. The interface layer between pile and surrounding soil was represented by thin layer element.
The basic concept of soil nailing is to reinforce and strengthen the existing round by installing... more The basic concept of soil nailing is to reinforce and strengthen the existing round by installing closely spaced steel bars, called "Nails", into a slope as construction proceeds from "top-down". This process creates a reinforced section that is in itself stable and able to retain the ground behind it. Soil nailing technique is used to support new very steep cuts with advantage of strengthening the slope with excessive earth works to provide construction access and working associated with commonly used retaining systems. In the present research work a parametric study has been made using commercial computer program "Slide 6", which utilize different methods for solving slope stability problem, Bishop method has been used herein to analyze un nailed and nailed slopes with granular soil, different slope heights and angles have been considered. Some of nails parameters have been studied here in, positions of nail, length of nail, angle of nail inclination, and nail spacing. The optimum length of nail depends on height and angle of slope. The optimum angle of nail is found to be ranged between (10-25) degree down from the horizon, but it's also relates with the angle of slope. The spacing of nail was found to be (1 m) to give the best improvement of F.S.
This research is empirical method for estimating the quantity of seepage under sheet pile wall, w... more This research is empirical method for estimating the quantity of seepage under sheet pile wall, which influence on the stability and durability of the sheet pile. Flow net plotted by using Visual Basic Program, which gives greater number of flow lines and equipotential lines. The comparison between the results of visual program and the field observations explains excellent agreement.
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Papers by Nadher Al-Baghdadi