Muhammad Mubaraki

Progressive failure prediction of pinned joint in quasi-isotropic laminates used in pipelines

To simulate the progressive failure of pinned joint in quasi-isotropic [0/45/45/90]s glass fiber reinforced polymer (GFRP) composite laminates used in pipeline, 3-D finite element model is employed in the present work. Hashin failure criterion as a progressive damage model associated with Virtual-CrackClosing-Technique (VCCT) delamination model has been adopted to predicate the failure due to fiber breakage, matrix cracking and delamination in composite pinned joint. This technique may be an innovation for this paper. W/D has been changed to get different modes of failure, i.e. tension, shear-out and bearing failures, in composite pinned joint,. The failure mode for GFRP composite pinned joint has been predicted finally after prediction the failure at each ply laminate of stacking sequence [0/45/-45/90]s. An experimental work of pinned joint in quasi-isotropic GFRP composite laminates has been conducted to validate the present numerical results. The numerical and experimental results showed an agreement between them. Therefore, the present 3D finite element model can be considered as a good candidate to expect the progressive damage in composite pinned joints.

Evaluating Settlement on King Faisal Road Using GIS Analysis Techniques

This study aims to determine the reasons for settlement on King Faisal Road in Jazan City, Kingdom of Saudi Arabia, using Geographical Information System (GIS) techniques. Pavement engineers and contractors in Saudi Arabia are often faced with the challenges of constructing pavement for desert sand dune areas, mountainous areas, and the sabkha or salt flat areas, and they are faced with problems of settlement. King Faisal Road in Jazan City is selected as a case study. This road suffers distress problems such as settlement and bleeding. The primary objective of this paper is to investigate the reasons for the settlement on King Faisal Road in Jazan City by using two criteria of investigations. These criteria of investigation include soil and asphalt laboratory test results, and analysis of the site’s drainage system by Geographic Information System (GIS). The obtained results show that the reasons for settlement along King Faisal Road were focused on the drainage systems on the road and the traffic loading characterized by different classes of vehicles. The purpose of this investigation was to determine the cause of settlement inconsistencies in pavement surface elevations at the distressed locations. There are different distressed locations on King Faisal Road, but the main distressed site is located in the area of intersection between King Faisal Road and Prince Sultan Road, encompassing the intersection’s traffic signal domain. Proposed solutions to the problem of settlement are presented in this paper. One of these solutions: Drilling under the road layers (sub-base, base, and asphalt) to a depth of at least five meters and drying the area using the appropriate means of water drainage such as vertical drilling wells. The second proposed solution: Using a chemically-enhanced solution to a depth of at least ten meters under the road layers, with a soil injection of high-softness cement, to increase the durability of the soil in the settlement areas.