Study on the Shear Capacity of the Wet Joint of the Prefabricated Bridge Panel with a Special-Shaped Shear Key

Steel-concrete composite beam has been widely applied in civil engineering, and the concrete during operation may crack due to the large shear force at the wet joint. A new concrete panel shear key with the boss is designed to strengthen the shear capacity of the wet joint part. Three different configurations of specimens are tested to study the shear capacity of the wet joint. These specimens include plain concrete specimens with shear keys, specimens with reinforcement and no shear key, and specimens with both shear keys and reinforcements. An experimental study is designed and conducted to verify the shear capacity of each specimen. The experimental results show that the ultimate shear capacity of the new wet joint structure is 73% higher than the conventional one. Meanwhile, the shear capacity of the new wet joint structure is theoretically predicted, and the finite element models are established to demonstrate the effectiveness of the experiment and the good performance of the new wet joint design.

Seismic Behavior of Innovative Hybrid CLT-steel Shear Wall for Mid-Rise Buildings.

This paper examines the seismic behavior of CLT-steel hybrid walls at six- and ten-story heights to increase seismic force resistance compared to a conventional wooden wall. The ultra-strong shear walls proposed in this paper are called Framing Panel Shear Walls (FPSW), which are based on a robust articulated steel frame braced with CLT board panels and steel tendons. Timber structures are well-known for their ecological benefits, as well as their excellent seismic performance, mainly due to high strength-to-weight ratio compared to steel and concrete ones, flexibility, and redundancy. However, in order to meet the requirements regarding the maximum inter-story drifts prescribed in seismic design codes, a challenging engineering problem emerges, because sufficiently resistant, rigid and ductile connections and lateral assemblies are not available for timber to meet both the technical and economical restrictions. Therefore, it is a necessity to develop strong and cost-effective timber-based lateral systems, in order to become a real alternative to mid- and high-rises, especially in seismic countries. In this investigation, the dynamic response of cross-laminated timber (CLT) combined with hollow steel profiles has been investigated in shear wall configuration. After experimental work, an investigation was also carried out into numerical modelling for simulating the cyclic behavior of a hybrid FPSW wall and the spectral modal analysis of a six- and a ten-story buildings with FPSW. A FPSW shear wall can double the capacity and stiffness.

Numerical Assessment of Lateral Deflection Equation of Single-Storey Light-Frame Wood Shearwalls

Based on the decomposition of the deflection into bending, panel shear, nail slip, and base rotation terms, the nonlinear four-term equation specified by the Canadian wood design code provides an estimate of the total lateral deflection of light-frame wood shear walls. This paper reports the creation of a numerical procedure for separating the responses for each term using a detailed nonlinear finite element modeling (FEM) that simulates individual components of shear walls. Since sheathing panel stiffness is not considered in computations of the bending term, the study reveals that bending deformation results calculated using the equation are more conservative than the FEM results. The nail slip term does not reflect the real nail base connection properties. A new equilibrium equation for determining the lateral deflection due to base rotation is presented. The equation is generally conservative because of the omission of some practical considerations.

Seismic response of single-storey buildings with flexible diaphragms

The roof framing in single-storey buildings with large foot prints, generally used for commercial, educational, or institutional purposes, often consists of a flexible steel deck or wood panel diaphragm. Resistance to seismic lateral loads is provided by steel bracings, masonry shear walls, concrete shear walls, wood panel shear walls, or cold formed wall systems. The response of such buildings to seismic loads is strongly affected by the flexibility of the roof diaphragm. Diaphragm flexibility alters the manner in which the inertia forces, shears, and bending moments are distributed along the length of the diaphragm. In addition, it causes a significant increase in the ductility demand on the lateral load resisting system that is expected to be strained into the inelastic range under the design earthquake. Results of a study on the linear and nonlinear seismic response of buildings with flexible diaphragms are presented.