Tensile Performance of SHCC Road-Bridge Link Slabs in Fully Jointless Bridges

Deformation of the main girder is absorbed by a continuously reinforced concrete pavement (CRCP) with microcracks in fully jointless bridges. The conventional fully jointless bridge has been challenged by durability and reliability issues because the CRCP is vulnerable to crack and hard to control the crack width when it suffers temperature variation. In this paper, a new type of fully jointless bridge with the road-bridge link slabs using strain-hardening cementitious composite (SHCC) material is investigated. First, an experiment was carried out to study the material properties of SHCC material for a preliminary assessment of road-bridge link slab performance using this material. Results found that SHCC is adequate for link slabs for its high tensile ductility and fine cracks development. Second, an SHCC slab model tensile test was carried out to study the absorptive capacity and the crack distribution of the SHCC slab. Results verified the high absorptive deformation capacity of the SHCC slabs. When the longitudinal deformation reaches 10 mm, the surface cracks in the SHCC slab are fine and dense, the crack width is kept in 80 μm, and the internal force is small. Third, by comparing the tensile test results with a conventional CRCP slab with same length, it is found that an SHCC slab has higher absorption capacity, better crack distribution, and smaller internal force than a CRCP slab. Finally, through ABAQUS finite element modelling, the stress performance of SHCC road-bridge link slabs is simulated using a trilinear constitutive model. The calculated results are consistent with the experimental results.

Investigation on Flooding-Resistant Performance of Integral Abutment and Jointless Bridge

Bridge washouts connected to flood events are deemed one of the main reasons for structural collapse. Compared to traditional continuous jointed bridges, integral abutment and jointless bridges (IAJBs) have better lateral stability because there are no expansion devices. The mechanical performance of Shangban IAJ bridge, located in Fujian, China, is thoroughly investigated by Finite Element Analysis (FEA). The numerical model is created and validated based on experimental results obtained from static load tests performed on the bridge. A detailed parametric analysis is carried out to assess the correlation between the flood-resistant performance and a number of parameters: skew angle, water-blocking area, span number, pile section geometry, and abutment height. Except for the abutment height, other parameters significantly affect the bridge performance. Furthermore, the change in the span number has a meaningful impact only when fewer than four spans are modeled. Finally, pushover analyses estimate the maximum transverse displacement and the sequence of plastic hinge creation as well as the mechanical behaviour of the structure under lateral flood loads. The analysis results show that IAJBs have better flooding-resistant performance than conventional jointed bridges.

COMPARISON BETWEEN TWO MODELING ASPECTS TO INVESTIGATE SEISMIC SOIL STRUCTURE INTERACTION IN A JOINTLESS BRIDGE

Seismic waves propagate through a series of rock and soil layers before they interact with the foundation and superstructure. Besides the original characteristics of the earthquake motion at the instant of fault rupture, it is also important how the soil site responds in terms of amplification or de-amplification of different frequency contents. Considering possible nonlinear response of soil and structure, a coupled soilstructure model is required to efficiently capture the dynamic behavior of the entire system. This paper focuses on comparison of two modelling strategies for Soil-Structure Interaction (SSI) aiming to define the behavior of a jointless bridge, namely (a) one with an explicit full-scale soil domain with bridge model and (b) another with Beam on Dynamic Winkler Foundation (BDWF)/ nonlinear soil springs. Finally, the structural components that effect overall behavior of superstructure is compared between these two models and the variation of seismic response from performance-based study is discussed.