Page | 30 Available online at http://arjournal.org ISSN: 2423-4796 Applied Research Journal Vol. 4, Issue, 2, pp.30-37, February, 2018 *Corresponding author: Mohammed Shaker Mahmood, Email: mohammedsh.alshakarchi@uokufa.edu.iq Asst. Prof., PhD in Geotechnical Engineering, Faculty of Engineering, University of Kufa, Iraq. APPLIED RESEARCH JOURNAL RESEARCH ARTICLE PREDICTION OF DISCREPANCY SETTLEMENT BEHAVIOR OF SAND SOILS Mohammed Shaker Mahmood Department of Civil Engineering, Faculty of Engineering, University of Kufa, Iraq. ARTICLE INFO ABSTRACT Article History: Received: 06, February, 2018 Final Accepted: 12, March, 2018 Published Online: 20, April, 2018 Compression of soil is manifested in settlement of foundations. Differential or discrepancy settlement, which may be disastrous, leading to cracking and collapse of the structural members. Settlement magnitude and rate in addition to differential settlement are the most important issues in stability analysis if structures. The recent paper is investigated the settlement behavior of the sand soil in Al-Najaf city, Iraq. The samples are from two neighbor locations in the site of University of Kufa and each sample are remolded to the specific density and moisture content. To predict the settlement, two sets of single Oedometer tests on the selected soil samples are made with three stress levels, 50, 100 and 200 kPa. The settlement is quick and be achieved within few minutes. The results illustrate that there is initially different behavior of the settlement from the two sets of tests. While for the higher density about 60% of the final settlement is reached immediately for different stress levels whereas the sample of lower density sample reached 80% of final settlement at first two stress level the 70% under the third stress level. This diverge in the settlement results decreases with increase the stress and the settlement is in same trend and magnitude for both test sets. The final settlement ratio is about 5%. The compression index (Cc) is 0.0533 and the expansion index (Cr) is 0.003. © Copy Right, ARJ, 2018. All rights reserved Key words: Al-Najaf, Sand Soil, Settlement, Settlement Rate. 1. INTRODUCTION Settlement is the void ratio decreases due to the external loads whereas the volume of solid particles is unaffected. The geotechnical properties of soils are far more complex and difficult to estimate. The selection of soils for footing of any construction is not within the engineer's control. The compressibility changes with density for sand and silt soils [1]. The problem of the settlement accurate prediction is the value of the total settlement and the settlement rate [2]. There is an increase of literature that distinguishes the importance of the structures collapse due to settlement. In case of sand foundation, the increase in size of footing will improve the bearing capacity of the supporting soil, and square footing has revealed better load-settlement performance as compared to circular and rectangular shapes [3]. In case of shallow foundation for a given loading system, the design engineer must consider footing placement (proper location and depth), safety bearing capacity (proper footing design and the strength of the foundation materials) and tolerable foundation settlements [1]. In coarse soils, elastic settlement is the major part of the settlement [4]. The design criteria of foundation on a cohesionless soils depends on settlement rather than on bearing capacity failure [2]. The critical factor is the differential settlement between the parts of a structure [1]. Immediate settlement is occurring within the application of the load or within 7 days' period [5]. Previous research has established that the main component of soil in Al-Najaf city is sand of more than 70 percent according to statistical analysis of 150 records to depth of 14m. in this city. The issue of gypsum has received considerable attention in the city. The gypsum content ranged from 10% up to 30% within 2m depth from the natural ground surface [6,7]. The bearing capacity of Al-Najaf city was decreased when the soil had been subjected to the water soaking period [8]. In addition to there was an increasing in the