دانلود رایگان مقاله انگلیسی مطالعات عددی در مورد پاسخ لرزه ای سازه های پل با ستون های قطعه ای - الزویر 2018

abstract

Recently, extensive experimental and numerical studies have been carried out to understand the seismic behaviors of segmental columns. Very limited studies, however, focused on the seismic performances of a whole bridge system with precast segmental columns. This paper carries out numerical studies on the seismic responses of bridge structures with precast segmental columns. For comparison, the seismic responses of the bridge with conventional monolithic columns are also calculated. The twodimensional (2 D) finite element (FE) models of these two bridge types are developed by using the FE code OpenSEES. The segmental column and monolithic column are simulated by the simplified lumped-mass model and fiber-based model respectively and validated by the previous experimental studies. The calibrated column models are then incorporated into the whole bridge structures to calculate the structural responses. The influences of pounding, frequency ratio and gap size on the structural responses are investigated and discussed. Numerical results show that the bridges supported by the segmental columns or monolithic columns have very different seismic responses.

6. Conclusions

Bridge structures with precast segmental columns are more and more widely used in engineering practices. These bridge structures are normally located in the low seismicity areas due to the lack of understanding on their seismic performances. Recently, extensive research works have been carried out to examine the seismic performance of segmental columns. The investigations on the seismic responses of a whole bridge structure with segmental columns are rare. This paper carries out numerical studies on the seismic responses of bridge structure with precast segmental columns. For comparison, a similar bridge with conventional monolithic columns is also analyzed. The following conclusions are obtained based on the numerical results:

1. The bridge with segmental columns shows smaller residual displacement but more violent deck vibrations compared to the bridge with monolithic columns.

2. Pounding can reduce the bridge peak responses and residual displacement especially for the monolithic bridge.

3. Larger residual displacement can be generated when the vibration characteristics of the adjacent bridge frames are the same.

4. The influence of different gap sizes on peak displacement responses is similar to both bridges with monolithic and segmental columns. However, the influence of gap size on the residual displacement of the two bridges is different. For the monolithic bridge, larger gap size normally results in larger residual displacement. For the segmental bridge, the influence of gap size on the residual displacement is not prominent.

5. To completely preclude pounding, larger separation gap is required for the bridge with monolithic columns compared to the bridge with segmental columns.

6. When the gap size is small, bridge with monolithic columns experiences more number of poundings. When plastic deformation occurs, the bridge with segmental columns suffers more number of poundings.