Ismail Othman

Experimental investigation and finite element modelling of the effects of flow velocities on a skewed integral bridge

This paper presents finite element modelling of the effects of different flow velocities on the structural behaviour of a skewed integral bridge. Flow velocities affect the scour depths at the piles of a bridge and thus affect its structural behaviour. Laboratory tests on a scaled-down hydraulic model along with numerical modelling were performed to simulate the structural behaviour of the scoured integral bridge. A finite element package was used for the numerical modelling work, and the displacements and strains corresponding to the measured locations on the physical model were extracted. The experimental and numerical results for the case of maximum scour depths were compared.

Strength and deformation characteristics of engineered cementitious composite slabs with different polymer fibres

This paper presents a study on the compressive and flexural strength of engineered cementitious composite (ECC) cubes and slabs, reinforced with various polymer fibres. The type of fibre, fibre content and aspect ratio were the parameters considered in this study. For all types of fibre, the compressive strength of the ECC decreased as the reinforcing index increased. For the ECC polypropylene fibre (PP) slabs, the first crack strength significantly decreased with an increase in the fibre content. For the ECC polyethylene fibre (PE) slabs, the first crack strength decreased as the reinforcing index increased. For the ECC PE slabs, the usage of PE 1600D fibres showed a substantial increase in flexural strength due to their higher tensile strength and E modulus. The ECC PP slabs behaved like plane concrete due to the zero value of flexural strength, which was attributed to the weak interfacial bonding with the cement matrix, low tensile strength and E modulus of the PP fibres. The highest ductility was observed for the ECC-PE slabs with the highest recorded deflection values; these values achieved many extended multiple cracks and an extensive area under the load–deflection curve indicating high energy absorption capacity.

Externally Prestressed Monolithic and Segmental Concrete Beams under Torsion: a Comparative Finite Element Study

Externally Prestressed segmental beams are widely used in the construction of bridge structures today. These beams have many attractive advantages for rehabilitation and strengthening of existing structures as well. However, segmental beams experience significant effect under combined stresses at the joint interfaces between segments. This paper presents a finite element study on the effect of torsion on the structural behavior of both external prestressed monolithic and segmental concrete beams. Geometric and material nonlinearities were included in the study. The results show significant difference in the behavior of monolithic and segmental beams under torsion.

Torsional Moments in Y-Beam Bridge Deck Under Malaysian Abnormal Load

Publisher Summary This chapter discusses torsional moments in Y-beam decks under Malaysian abnormal live load—SV20 units—with different deck spans and different beam spacings in beam and slab right bridge decks, according to the British Bridge Code, BS 5400. Three bridge spans are adopted—namely, 16.00 m, 22.00 m, and 29.00 m. For each span, a series of analyses is carried out with three chosen beam spacing—namely, 1.00 m, 1.25 m, and 1.50 m. The width of all bridge decks is kept constant at 10.30 m, with New Jersey parapet. End diaphragms of 0.50 m widths have been chosen for all the bridge decks. This chapter shows that the torsional moment must be considered in Y-beam design. In general, where torsional resistance or stiffens of member has not been taken into account in the analysis of the structure, no specific calculations for torsion will be necessary, adequate control of any torsional cracking being provided by the required nominal shear reinforcement.