整体式桥台-桩基-土相互作用内力计算方法研究

整体桥具有使用寿命长、施工方便、造价及养护费用低等特点,目前在国内外得到了广泛的应用与推广.以某整体桥为工程背景,设计制作了桥台-桩基结构试验模型,开展了整体式桥台-H形钢桩-土相互作用低周往复荷载拟静力试验,主要研究了桥台和桩基的应变、弯矩与剪力等.试验结果表明:桥台正向移动时桩身应变呈现"酒杯"形分布,负向移动时呈...

Calculation Method of Internal Force of Integral Abutment Pile Foundation-soil Interaction

The integral abutment jointless bridge (IAJB) has advantages such as long service life, convenient construction, lower cost of building, and maintenance. Currently, it is widely used globally. A test model of an integral abutment-pile foundation structure was designed and manufactured based on a practical IAJB. The pseudo-static test under low-cycle reciprocating displacement load was conducted to study the interactions between the integral abutment-H-shaped steel pile and soil. Then, the strain, bending moment as well as shear force of the abutment and the pile foundation were mainly studied. The experimental results show that the strain distribution of the pile body is in the shape of a cup when the abutment moves to backfill positively, while it is in the shape of an olive when the abutment moves negatively. Moreover, the maximum compressive stress and tensile stress under the positive displacement load are greater than those under the negative load. Therefore, the internal force of the pile foundation, when the temperature increases, is greater than when the temperature drops, indicating that the H-shaped steel pile foundation is more adversely affected when the temperature rises in the summer months. It is suggested that the overall bridge closure temperature should be slightly higher than the annual average temperature to reduce the adverse impact on the pile foundation resulting from high temperatures. Additionally, the calculation also shows that when the negative load is applied, the bending moment and shear force of the pile body calculated by these methods deviate marginally from the test results, and the distribution law is similar to that of the traditional pile foundation. However, in the case of positive loading, the pile bending moment and shear force calculated, using these theories behind the abutment or the bridge specification, deviate considerably from the test results, and the distribution law is different from that of the traditional pile foundation. In this paper, the method of polynomial fitting and Huang-Lin can be more accurately calculated the integral abutment pile-soil interaction of bending moment and shear force. This method can be used in practical engineering to calculate the internal force of the abutment and the pile of the integral bridge and form a frame of reference for the design and application of integral bridges in the future.