A Parametric Study of Piled Raft Foundation in Clay Subjected to Concentrated Loading

The use of piled raft foundation in building and infrastructure constructions is increasingly popular because of its effectiveness in reducing overall and differential settlements. Parameters influencing the performance of the piled raft foundation need to be comprehended in order to optimize the design of the piled raft system. Most of the current available literature focused on the piled raft foundation subjected to a uniform distributed load in sandy material. This parametric study aims to provide insights into the performance of the piled raft foundations subjected to concentrated loading in clay. A series of 2D finite element analyses were performed to investigate the influencing parameters affecting the load distribution and settlement behaviour of the piled raft. The results suggested that increases in both pile length and raft thickness, as well as a decrease in pile spacing would reduce the differential settlement of the piled raft. Comparatively, raft thickness was the most significant controlling parameter affecting the differential settlement. The study also revealed the importance of placing the pile nearer to the location of concentrated load as it would yield a more uniform load distribution, and hence a lower differential settlement.

EFFECT OF CORROSION LONGITUDINAL STEEL BARS ON THE FLEXURAL STRENGTH OF RC BEAMS

The main objective of this research is to investigate the effect of corroded steel bars on the ultimate flexural capacity of reinforcement concrete beams. The experimental work consists of four RC beams with dimensions (150×200×1200) mm tested under two-point concentrated loading. The major parameter of the current research is corrosion period (5,10,20) days. The amount of longitudinal and transverse reinforcement, concrete strength and, the other parameters were kept constant for all samples. The comparisons between specimens are based on the visual cracking loads, ultimate loads, deflection, cracks pattern and mode of failure. Results showed that visual first cracking load, and ultimate loads of corroded RC beams were decreased with increase corrosion durations relative to the control beam as a result of the corrosion process. The mode of failure was flexural failure for all specimens. Corrosion caused decreasing percentage in weight of steel bars and cross-sectional area of longitudinal steel bars. This percent increased as exposure time to corrosion process increased by 8.5% and 28.39% for 20 days respectively.

THE SIMULATION ASSESSMENT OF THE VENEERING LAYERS OF PROSTHETIC CROWNS IN CONCENTRATED CONTACT

The aim of the study is to simulate and analyse the distributions of stresses and resultant displacements during concentrated loading of the layered material compositions used in prosthetic crowns in order to assess their resistance and demonstrate the impact of strength parameters of the veneer and framework on the transfer of external loads. The research materials are samples replicating the layered structure of prosthetic crowns. The load-bearing layers were made using CAD/CAM technology, and the dedicated veneering layers were fired or polymerized on the frameworks and constituted the top structure for cooperation during occlusion. If the material of the veneering layer differs from the material building the framework, for example, in the ceramic-metal type, spreading of the resultant displacements to the framework and high values of shear stress at the border of the veneering layer and the framework may be unfavourable and cause the veneer layer to chip off. This distribution of stresses and displacements may have a much smaller impact on the ceramic veneering of a ceramic or glass-ceramic framework, as both layers are much more homogeneous in terms of material.

Experimental and finite element study of optimal designed steel corrugated web beams

The structural performance of standard steel sections in long-span constructions gradually deteriorates due to wider and slighter webs that tend to buckle. This is the characteristic problem of plane webs. Corrugated steel web plates allow a considerable reduction of weight and increasing the web capacity of the beam. The experimental test results of optimal designed corrugated web beams, fortifying thin-walled steel girders without stiffeners, under load conditions, have been compared with the 3-D plane strains finite elements ( FE) model in this paper. The span of fabricated corrugated web beams ( CWB) is chosen as 5 m. These optimally designed CWB are exposed to a single concentrated loading, two-point loading, and partially distributed loading, respectively. The design methods for CWB are firefly optimization and hunting search algorithms. The implementation of design constraints is based on the EUROCODE, DIN, and DAST-Ri. 015 code provisions. The load-displacement curves, the residual load capacity, and the failure form of eighteen tested corrugated web beams are inquired in depth along the experimental process. The structural analysis software ANSYS is used for the simulation of the experimental study, the verification of all test results, and the investigation of the behavior of failure forms.

Effect of mortise and tenon size on compressive and tensile strength of a box connected by dovetail keys

Compressive and tensile strengths were considered for a box connected by dovetail keys under different mortise-and-tenon sizes. Poplar wood modified by melamine resin (MF modified poplar wood) was chosen as the experimental material, and the experimental study was carried out on the box using the concentrated loading method. The results showed that the ratio (T) of hole depth to slope height had a significant effect on the structural strength of the box connected by dovetail keys when other dimensional parameters were the same. When T was equal to 75%, the compression and tensile strength of the box was the highest, and the joint had better recovery and deformation ability. When T` was equal to 50%, the box strength was the worst, and the joint damage was the most serious in both types of loading. In addition, the measurement standard of the displacement was determined through preliminary experimentation. The compression quantity was 8 mm, and the stretching quantity was 5 mm. The latter experiment showed the reliability of the pre-experiment.

Behaviour of Steel Fiber Reinforced Polymer Cement Concrete Slab Under Four Point Concentrated Loading

This article provides the behavior of polymer two way slab under four point concentrated loading. The slab with dimension of 600x600x75mm has been tested under simply supported condition. The slab was prepared with M20 grade concrete and this concrete mix was supplemented by 10% Bethemcharla stone powder and 10%Bisphenol-A epoxy polymer. In addition those additives steel fibers were added to the mix in the proportion of 0, 1 and 2% by volume. One more mix was cast without any additives and it considers as reference mix and used for comparison of other slabs. The slabs with additives in the mix showed superior performance in strength and stiffness characteristics. From the results it found that, the slab with 2% steel fiber showed 41.30% higher strength than the reference slab.