KUFA JOURNAL OF ENGINEERING

In the past, the arch represented one of the few structural systems which provide a possibility to cover large spans. Nowadays, the same importance is presented as the need increased with the increase of construction with large spans and with arched structures which are constructed in different shapes and from various materials such as brick, steel and reinforced concrete. The main aim of this study was to investigate the behavior and ultimate strength of concrete arched slab under flexural load. The main parameters considered in the present investigation are, concrete mix compressive strength, thickness of slab, area of steel, curvature and support conditions. A total of fourteen samples of the arched slab are constructed and tested under two-point load. The behavior of the samples is observed by reading the deflection at mid-span and observing the crack patterns and strains at top and bottom fibers. The behavior of arched slab samples is linear up to first cracking load and still linear up to (35% - 55%) from the ultimate load. The load-deflection curve at mid span of the arched slab may be idealized by bilinear curve. The increasing of compressive strength by 116% leads to increase the ultimate load by (15% - 25%). Increasing the slab thickness by 43% leads to increase the ultimate load by (6% -17%). Increasing the area of steel by 45% leads to increase the ultimate load by (29% - 34%). Increasing the curvature by 200% leads to increase the ultimate load by (6% - 28%). Changing the support from simply support to pin-pin leads to increase the ultimate load by (200% - 245%).

In this paper, the Static response of a circular skirt foundation resting on a sandy soil subjected to pure vertical load was analyzed numerically using finite element software, PLAXIS 3D 2020. Linear elastic model was adopted to describe the behavior of the shallow concrete circular foundation with (1m) diameter and (0.2 m) thick, as well as the soil underneath, with and without skirt . Different skirt's length to diameter ratios (L/D) (0.25, 0.5, 0.75, and 1.0), in addition to different skirt thicknesses (0.1 m, 0.15 m, 0.2m) were anticipated. The results shown that, in dry sand, existence of skirts improves the foundation performance effectively by increasing its load carrying capacity particularly when the skirt (L/D) ratio become larger. However, the increase in the thickness of the skirt has marginal influence and it can be neglected for design purposes.

Text document clustering (TDC) represents a key task in text mining and unsupervised machine learning, which partitions a specific documents’ collection into varied K-groups according to certain similarity/dissimilarity criterion. The multi-verse optimizer algorithm (MVO) is a stochastic population-based algorithm, which was recently introduced and successfully utilized to tackle many optimization problems that are complex. The original MVO performance is limited to the utilization of only the best solution in the exploitation phase (local search capability), which makes it suffer from entrapment in local optima and low convergence rate. This paper aims to propose a novel method of modifying the MVO algorithm called link-based multi-verse optimizer algorithm (LBMVO) to enhance the exploitation phase in the original MVO. Generally, LBMVO has outperformed or at least showed that it is profoundly competitive compared with the original MVO algorithm.

Islamic architecture has been characterized by timelessness and eternity, due to the property of flexibility and the possibility of physical formation in different methods, while preserving its sanctity and this is represented by engineering and the orientation towards the kiblah clearly and explicitly. The research proposed the coordinated response process, which is a biological process, that the organism shows when exposed to external influences to maintain a balance that guarantees it to continue life in two ways: The first is that the cell changes its shape while preserving its function, or changes its functional effectiveness by upgrading or weakening in its efficiency, but it maintains Its form, and each of them was discussed in Islamic architecture, by defining the research problem “the lack of knowledge about the patterns of coordinated response that the product of Islamic architecture adopts for the purpose of perpetuating it and maintaining its presence” and building a conceptual framework about the role of the concept in Islamic architecture, where two groups of architecture products were identified, a group It was represented by the selection of Islamic buildings with a historical dimension that have preserved their shapes over time while updating their functions, and other contemporary buildings in various shapes, but appear with one function, which is the religious function, for the purpose of investigating the patterns of coordinated response in them. The conclusion, Islamic architecture is based on multiple levels of a coordinated response with balance and moderation, which appear at levels of relativity, as it appears strong on one level and medium on another level. this makes it possesses permanence, both formally and intellectually

Because of its durability, structural ring footings have been used under the maritime structure’s shallow foundations for many years. so, the efficacy and application of shallow foundations ring footings typically are little understood. These footings was tested for the bearing capacity of this research in a laboratory. The impact of ring depth and stiffness on the bearing capacities of ring footing models was studied in this respect. Ring footings design was based on the structural and geometry requirements. it was estimated that using structural rings would increase the support capacities of both soil-rings and soil-footing depth by 1.62 times. The behavior of a ring footing resting on (sand, clay, sand over clay, clay over sand) soil exposed to vertical stresses was investigated in laboratory experiments. A small-scale physical model was built and tested to achieve this goal. included an aluminum circular footing with a diameter of 100 mm and a d/D ratio of (0,0.33,0.5,0.67,0.95) to see how the d/D ratio affected bearing capacity along with different embedding depths to observe how they affect depth and footing size affected bearing capacity. Because the number of drilling and filling operations decreases as it varies from conventional foundations in that it has an increasing number of ring footings. By using the peripheral ring, it is possible to avoid excavating in adjacent construction sites subsurface soil, which reduces the amount of disturbance. This structure appears critical for expense and productivity given the potential advantages of using rings as feet. Meanwhile, further research into the adjacent foundations' bearing capacity and settling activities is needed to show their advantages to practical engineers

Soils shear strength is one of the significant properties for geotechnical engineering purposes. Shear strength components, cohesion and angle of internal friction, are used in soil’s bearing capacity determination, which is the key factor in construction developments. Unconfined compression test is a common type of soil shear testing to obtain the unconfined compressive strength (UCS) and cohesion (C). UCS is a widely-used soil’s geotechnical characteristic for design and practice of soil foundation of construction projects. The laboratory determination of UCS is tiresome, which requires very-accurately prepared field sample and in some way a time-consuming, the purpose of this study is established. This study is aimed to establish a prediction model for Sulaimani soils UCS determination via using multiple linear regression methods. Models were created from undisturbed fine-grained soil samples collected from three different locations at Sulaimani Governorate in Kurdistan Region of Iraq. The precision of the established equations is tested by utilizing three different versions of coefficient of determinations namely R2, adjusted-R2 and predicted-R2. Box-Cox statistical transformation of data enhanced the performance of the regression models. The results showed a reliability of the transformed-data regression model to predict UCS with R2 of 0.80, R2-adjusted of 0.80 and R2-predicted of 0.77.