Print ISSN: 1681-6900

Online ISSN: 2412-0758

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Volume 39, Issue 8

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Volume 39, Issue 8, August 2021

Settlement of Shallow Foundation in Dry Sand Under an Earthquake

Mohammed Al-Neami; Falah Rahil; Ahmed Hussain

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1206-1215
DOI: 10.30684/etj.v39i8.527

Seismically induced settlement of buildings with shallow foundations resting on dry sand soils has resulted in severe damage in recent earthquakes. A multi-degree of freedom shaking table and a fixed container were manufactured and used to study the foundation settlement. Series of shaking experiments on the shallow foundation situated in a center of the container and atop of a dry sandy soil has been performed to identify the mechanisms involved to calculate the foundation settlement induced by earthquake shaking. In this research, the important factors are identified, including shaking intensity, the soil relative density, the degree of freedom and the building’s weight. Two relative densities (55 % and 80%) are used and three local magnitudes of earthquakes (5.8, 6.4, and 7.2) (Anza, Jalisco, and Guerrero) respectively with one and two degrees of freedom. The results of the shaking indicated that shallow foundation settlement on the dry sand increases with the increase of the local magnitude of earthquakes and maximum acceleration. In the case of Anza, the percentage decrease in the settlement between the relative density of 55% and 80% for systems (x and xy) is (47% and 42%) respectively. While in the case of Jalisco and Guerrero, the percentage decreases in their settlement and for the same systems is (11% and 57%), (36% and 36%) respectively. The degree of freedom has an impact on the foundation settlement; it is proportional to the degree of freedom. Also, the results show that the settlement decreases when the relative density of sand increases.

Earthquake Response of Model Footings on Soft Clays Strengthened by Stone Columns

Ann Raheem; Mohammed Fattah; Makki Al-Recaby

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1216-1222
DOI: 10.30684/etj.v39i8.1651

The objective of the present study is to understand the behavior of soft soil strengthened by stone columns under dynamic seismic load. Ordinary and encased stone columns were used under different conditions. The present study converges around the dynamic response of stone columns of lateral shaking, the interaction of soil frame for understanding settlement mechanisms and the prediction of dynamic load limitations of foundations in soft soils subjected to seismic load (during vibrations).  The results of this research will provide the basis for assessing measures to reduce the severity of seismic hazards and the seismic design of foundation structures in soft soils. As a result, soil models will be tested on the shaking table to make seismic ground vibration under several conditions (frequencies, undrained shear strength of soft soil, for stone columns type both ordinary and encased stone columns). It was concluded that the values of horizontal displacement increase by increasing the loading frequency, as well as the horizontal displacement is faster and greater at 2 Hz than 0.5 and 1 Hz in all cases. The rate of horizontal displacement increases in models on the soil of undrained shear strength cu= 15 kPa is greater than that in undrained shear strength cu= 25 kPa because increasing the strength of the soft soil leads to greater resistance to deformation and a decrease in the level of horizontal displacement.

Characteristics of Asphalt Binder and Mixture Modified With Waste Polypropylene

Mohammed Fattah; Wissam, Abdulkhabeer; Miami Hilal

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1224-1230
DOI: 10.30684/etj.v39i8.1716

Improving asphalt materials to develop the overall performance of asphalt binders and mixtures has been the focus of several investigations made over the past few decades. The application of discarded waste plastics in asphalt modification was one of the steps taken in this direction. Using waste materials in pavement construction would not only enhances asphalt properties but would also bring out significant saving in road material costs and help towards tackling disposal problems of such waste materials, which tend to be hazardous in as much as they can cause pollution of water, soil, and air. The purpose of this paper is to investigate the probability of using Waste Polypropylene (WPP) as modifier to enhance the properties of asphalt binder and mixture. In this paper, two types of asphalt binder (40/50) and (60/70) were used. Three percentages of WPP (1%, 3%, and 5%) were added to (60/70) asphalt binder/mixture to obtain the modified samples that were tested using several laboratory tests and their results were compared to original (60/70) asphalt binder/mixture and to those of (40/50) asphalt binder/mixture besides comparing with the Iraqi Specifications. The outcomes indicated that 3% of WPP was the optimum percentage that gave best results for asphalt binder and asphalt mixture compared to original and other percentages of asphalt samples and according to the Iraqi Specifications.

Function and Application of Geogrid in Flexible Pavement under Dynamic Load

Fatin Jebur; Mohammed Fattah; Ahmed Abduljabbar

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1231-1241
DOI: 10.30684/etj.v39i8.1771

Nowadays, the increasing demand for road transport makes maintenance and repair of road infrastructures key tasks of road engineering. The current experimental work consists of laboratory model experiments to understand the conduct of sand as a subgrade under dynamic load and its effect on the flexible pavement and base layer. The reinforcement is applied at the interface between the base and subgrade using SS2 type of geogrid. The road layers are exposed to harmonic dynamic load with two load amplitudes of 10 and 15 kN and two frequencies of 0.5 and 1 Hz. The vertical stresses in the road layers are measured using stress a gauge sensor. In the case of a reinforcing geogrid in the middle of the base course, the stress decreases by increasing the frequency and load amplitudes by about (23-42(. The best position for geogrid is in the middle of the crushed stone layer because it gives the lower displacement. In the case of a reinforcing layer at the middle of the base course layer, the stress and vertical displacement decrease with increasing in frequency and load amplitudes. When laying the geogrid between the base course and subgrade, a lower decrease in the stress and vertical displacement could be obtained with the increase in frequency and loads.

The Behavior of Piles Installed in Medium Dense Sand Within MSE Wall System

Salah Hamza; Shaymaa Kadhim; Saad Al-Wakel

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1249-1256
DOI: 10.30684/etj.v39i8.1848

Mechanically Stabilized Earth Walls (MSE) were widely used in several essential infrastructures, such as the abutments on a bridge. The need for a support base of a shallow or a deep bridge increased in the MSE wall system. In this research, factors affecting the performance of laterally loaded piles embedded in medium dense sand with a relative density of 50% behind an MSE wall were studied using lower-scale models in the laboratory. For instance, the effect of pile offset and the slenderness ratio on the pile's lateral capacity and pressure on the MSE wall. Three different slenderness ratios were introduced (i.e. L/D of 19.3, 21.7, and 24.1). The results showed a significant increase in pile lateral capacity occurring with the increase in pile offset or slenderness ratio (i.e., L/D). While increasing the pile offset reduced, the pressure on the wall so that the wall's effect will be insignificant when the pile offset reaches a value of 6D.

Carbon Fiber-Based Cementitious Composites for Traffic Detection and Weighing In Motion

Dhurgham Ghadhban; Hasan Joni; Ali Al-Dahawi

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1250-1256
DOI: 10.30684/etj.v39i8.1875

New self-sensing cementitious composites embedded in the highway pavement for vehicle detection and weigh during motion is fabricated. Smart carbon fiber (CF) reinforced cement-based materials with high sensitive property are used as sensors. These smart composites may be able to detect the traffic and sense the weight in motion, thanks to their piezoresistive property. Cement-based sensors capability to vehicle detection was investigated in a real field at the University of Technology campus. Findings clarify that the CF-Based cementitious composites provide have a great potential to use as sensors for detect traffic and its composition also it possibly identifies different vehicular axle loadings (weigh during motion).

Variation of Consistency Limits and Compaction Characteristics of Clayey Soil with Nanomaterials

Noor Tarsh; Mohammed Al-Neami; Kawther Al-Soudany

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1257-1264
DOI: 10.30684/etj.v39i8.1930

The arrangement of the soil for every ground structure is so important and must be efficient to sustain the whole structure. The variables and properties that have influenced their behavior must be well known. The building constructed on soft soils may fail due to their low strength, and an excessive settlement of the soil under a constant load could occur, therefore, the improvement for such soils must be carried out before construction to eliminate or decrease the maintenance cost or failure in buildings. Nowadays, one of the new technologies using to improve problematic soil is nanomaterials. In this study, experimental tests were conducted to: Investigate the effect of using conventional materials and nanomaterials on the physical properties (consistency limits and compaction characteristics) of soft soil. The soft soils were gathered from one site and process with four material types (fly-ash, silica fume, nano fly-ash, nano-silica fume). Additives were supplement in a tiny amount (≤5%) by the dry weight of the soil. The results showed a significant improvement in maximum dry density and plasticity index and the improvement depends on the type of nanomaterials. The maximum dry density has increased as the content of nanomaterials has increased until this value of maximum dry density reduces the strength of the soil to the optimum percentage. Thus, even at a low dose, the addition of soft particles such as nano materials may improve soil characteristics.

Distribution of Pressures on Modified Stepped Spillway by Using Toothed-Steps

Jaafar Maatooq; Ameer Jasim

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1265-1270
DOI: 10.30684/etj.v39i8.1957

In the present study a new steeped spillway shape at which “toothed steps” have been adopted instead of traditional steps to enhance the amount and distribution of water pressure along the chute of the stepped spillway. Experiments were conducted under a skimming flow regime, on five physical models of spillway one of which consisted of traditional steps used as a base model. For all investigated models, the chute angle was 45° with fourteen steeps each of 3cm height. Generally, the results show that the new shape models enhance the pressure distribution and reducing the potential for negative pressures along the chute, as well as, reducing the values of positive pressures that usually impact the tread. Specifically, close to the crest, the differences in pressure values being clearly large between the toothed steps modelsand the traditional steps. The new configurations of steps reduce the positive pressures between 116.66% to 1.28 % and the negative pressures were generally close to zero.

Operation of Mosul – Dokan Reservoirs and Samarra Barrage Using HEC – ResSim Model During Dry Period

Thabet Abdulateef; Raad Irzooki; Ali Abbas

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1273-1280
DOI: 10.30684/etj.v39i8.1991

The issue of time series records containing low inflow than normal, such critical period results in shortage in reservoir storage, thereby reduction in the reservoir's releases that satisfy the demands. When the expected available water is less than the demand, releases may be curtailed, and the reservoir is under stress. This study presents an application of HEC – ResSim model to simulate the operation of Mosul, Dokan Reservoirs, and Samarra Barrage during the dry period 19992000 (modeling of historical data). Simulated results and recorded data were compared in order to, first improve the applicability of the software to simulate reservoir operation by calibrating the model during the period (1990 2000), and the second to identify the similarity and differences between recorded and model result during dry period. The aim of applying this software is to manage the operation of reservoir's system by establishing an operation policy for each reservoir. The simulation plots for Mosul Reservoir, exhibit storage pool elevation within the conservation zone including the ability of release of minimum downstream requirement and the operating Dokan pool reservoir is less than the conservation level. The upstream of Samarra Barrage pool elevation is affected by the look back level with the consideration of normal and minimum operation levels.

Punching Shear Resistance of Reinforced Concrete Flat Slabs Strengthened by CFRP and GFRP: A Review of Literature

Hadi Al-Maliki; Ali Al-Balhawi; Asma Ali

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1281-1290
DOI: 10.30684/etj.v39i8.2011

Flat reinforced concrete (RC) slabs or plates are still widely used in buildings and are most popular in single or multiple story floor construction systems. This is due to the ease and speed of implementation as well as the continuous smoothness that is provided in relation to the locations of members. Flat slab systems have an inadequate shear strength in both directions. Thus, they are subjected to a shear failure at their intersections with columns, which results in the collapse of a larger part of the structure. Shear failure occurs due to many reasons including changing the functions of the facility, the technical errors in the design and implementation procedures, an increase in the load, deterioration of materials, and poor quality. The carbon fiber reinforced polymer (CFRP) sheets/strips and glass fiber reinforced concrete polymer (GFRP) are used as a composite section formulated when there is a structural deficiency. Strengthening by using CFRP and GFRP provide an improvement in the punching shear resistance in both directions as well as flexural strength, ductility, and hardness. They are more suitable for a practical use as a substitute for other costly and difficult approaches such as increase the cross-sectional area of columns and so on. This paper reviews the up to date studies of enhancing the shear resistance of flat slabs by CFRP/GFRP and discusses the used materials for strengthening flat slabs and the used methods, which are used to implement these materials. Also, a summary for the cited studies are stated and the possible future works are suggested.

Determination of Suitable Areas for Establishment of Sports-City in Iraq's Center Using an Integrated Fuzzy Logic Algorithm and Geomatic Techniques

Haidar Mohammed

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1291-1300
DOI: 10.30684/etj.v39i8.2094

In recent times, many cities have clustered new sports infrastructures in concentrated areas to create a sports city. Al Hillah City as one of the biggest cities in the center of Iraq, because of many components' countryside relocation and natural expansion of population, and other has been distinguished; extreme population expansion and lastly evolution in need of planning in some inner-city areas and places. Consequently, designated areas in terms of premier spatial allocation and appropriate location for users of general services; sports services that are rapid, on time, and at ease access to them are essential that are not considered. A small- scale recognition has spent on critical aspects of sports utilization for land measure and appropriately locating. This issue has been minimized the premier performance of these spaces and creates problems for the city and its citizens. The premier performance of these spaces has been minimized because of the above-mentioned issue, which creates difficulties for the city and its residents. This research conducted based on the integration between Fuzzy logic algorithm and GIS techniques, spatial analysis tools in ArcGIS software were utilized to implement this method. The results showed that the most suitable areas include three areas that are located on the north-west and the south of the study area. On the other hand, the largest area located on the north-west location respect to Al-Hillah city, the center of Babylon Province, which is considered the proposed area to construct sports city. This study will be useful for decision-makers and stockholders by reducing cost, time, and efforts through decreasing field works.

Improvement of Soft Clayey Soil by Bio-polymer

Teba Abd; Mohammed Fattah; Mohammed Aswad

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1301-1306
DOI: 10.30684/etj.v39i8.2053

This examination explains the utilization of bio-polymer powder for clayey soil enhancement. The article concentrates around examining the strength attitude of the clayey soils built up with homogenous bio-polymer. Carboxy methyl cellulose was determined as bio-polymer material to build up the normal soft clayey soil. The biopolymer has been added to the soil with two separated rates (0.5 and 3%) by total weight of soil. Different tests were carried out to consider the impact of utilizing this polymer as a balancing out specialist on the geotechnical properties of soil. It was estimated that as the bio-polymer content expands in the soil, the specific gravity decreases, while the optimum water content (OMC) is expanded. The results showed different effects on Atterberg’s limits; by increasing the liquid limit(L.L) and plasticity index(P.I) while the plastic limit decrease. The tests additionally mirrored a huge improvement in the unconfined compressive strength (UCS) of the treated soils. With the increment in biopolymer content, the consolidation index (Compression index Cc and recompression index Cr) decrease.

Shear Strength of Reinforced Fibrous-self Compacted Concrete Box Girder using Recycled Concrete Aggregate

Mohammed Hadi; Eyad Sayhood; Ali Resheq

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1307-1320
DOI: 10.30684/etj.v39i8.2100

Protection of environmental and conservation of natural resources is a fundamental issue in today’s world. In this research, the shear behavior of reinforced concrete box girders with recycled aggregate (RA), steel fiber, and internal diaphragms were investigated. Eleven reinforced concrete box girders with typical longitudinal and transverse reinforcement were tested under two point loading until failure. The RA was prepared by crushing the collected waste of concrete from the laboratory test cylinders and cubes. The experimental variables considered include; RA percent of 50%, 75%, and 100%(replacing from NA), steel fiber with volumetric ratios (Vf) of 0.5%, 1.0%, and 2%, diaphragm numbers (two and three).The test results revealed that the shear strength of the box girders affected by the RA content, the ultimate load was decreased by (32, 25, and 19) % for the (100, 75, and 50) %RA concrete, respectively in compared with the control specimen. In contrast the steel fiber was more effective in strengthening of the RA concrete specimen, for the (Vf) of 0.5%, 1.0%, and 2.0% with non-fibrous 100% RA concrete, the strengthening were (25, 40, and 77) % respectively. Moreover, when 1.0% steel fibers added to the 100%, 75%, and 50%RA concrete respectively, the strengthening were (40 ,45 ,and48 )% compared  each with its reference specimen.  On the other hand, when two and three diaphragms used, the strengthening for the non-fibrous 100% RA concrete was (6% and 9%) respectively. cracking load, ultimate load, load- deflection, and concrete surface strain has been taken into consideration in this research.

Evaluating the Use of Eggshell Waste Ash in High Strength Concrete

Basim Amanah; Wasan Khalil

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1321-1327
DOI: 10.30684/etj.v39i8.2102

This study aims to determine the effect of incorporating eggshell waste as partial compensation from Portland cement material on high-strength concrete mixtures' performance. The properties studied are workability, compressive and flexural strengths, water absorption, dry density, and thermal conductivity. In the same trend, the environmental impact of the replacement mentioned above is evaluated. Four different weight percentages (0%,5%,10%,15%, and 20%) of the cement were replaced with eggshells ash. The results indicate that the incorporation of eggshell powder improves the compressive strength and flexural strength by about 14.7% and 6.5%, respectively, at 28days age over control concrete mixes at 15% replacement. The optimum replacement ratio was found to be 15% based on the strength. Furthermore, the results showed a reduction in water absorption and thermal conductivity as 15% of eggshell ash was used as a replacement by cement weight with 10.7% and 10.65 respectively, besides the reduction in the amount of cement used in the mixture. These results are positively reflected in supporting natural resources' sustainability and depleting the ozone layer by reducing the emitted gases.

Utilization of Satellite Images-Based Indices for Assessment of Al-Hammar Marsh Restoration plan

Bayda Dhaidan; Imzahim Alwan; Mahmoud Al-Khafaji

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1328-1337
DOI: 10.30684/etj.v39i8.2149

Wetland landscape characterization is an important component of determining the degree to which wetlands improve environmental conditions. The present study aims to create a model used to automated extraction of the land cover of the western part of the Al-Hammar Marsh south of Iraq, and then monitor the change in land cover overtime. A model builder in ArcGIS created based on a series of spectral-based indices included the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Moisture Index (NDMI), and the Normalized Difference Water Index (NDWI), the OLI satellite images from 2013 to 2020, ENVI 5.3 and ArcGIS 10.4 were used to achieve this goal. The results were six land cover classes: water, density vegetation, medium dense vegetation, low dense vegetation, wet barren land and, dry barren land. From the monitoring of the changing trend, it is clear that there is no improvement in the vegetation area, only a slight temporal improvement to 48% in 2017, an increase in water area for the years 2019 and 2020 to 47.33%, and 42.85% from the total area of the marsh respectively. The highest percentage was in 2019 while decreasing to the lowest rate of 14.05% for the year 2018.  The developed model was accepted and can be applied for reflectance Landsat 8 data in the study area and can be applied in the southern Iraqi marshes. It also can be applied to other types of sensors, but according to determinants.