芙蓉江大桥拱座混凝土–基岩抗滑稳定性研究

SLIDING STABILITY ANALYSIS OF CEMENTED CONCRETE-ROCK JOINT BETWEEN SKEWBACK AND BEDROCK OF FURONGJIANG BRIDGE

通过对混凝土–岩石胶结面剪切破坏过程中剪应力–位移曲线的分析,假设混凝土–岩石胶结面剪应力由混凝土与岩石之间的胶结作用和摩擦效应共同承担,从而建立考虑峰后胶结损伤的胶结面力学模型。室内混凝土–岩石剪切试验结果的反演分析表明,该模型可以很好地反映胶结面剪切破坏过程。利用建立的混凝土–岩石胶结面力学模型,对拟建的芙蓉江大桥拱座抗滑稳定性进行三维计算分析,结果表明:桥梁荷载下拱座–基岩胶结面剪切应力小于其抗剪强度,胶结面变形以弹性变形为主,量值较小,拱座–基岩胶结面不会产生剪切破坏。

Based on the analysis of shear stress-displacement curve of cemented concrete-rock joint, an assumption is proposed that the shear stress of cemented concrete-rock joint is dependent on the bonding strength and the friction effect of the cohesive interface. A new model of cemented concrete-rock joint considering the bonding degradation after peak stress is therefore established. The comparison of results of back analysis using the proposed model with ones from shear tests shows that the proposed model could describe the entire process of failure of cemented concrete-rock joint. Besides, a stability analysis of the foundation of Furongjiang Bridge is carried out using the proposed model. The numerical results show that the shear stress between the skewback and the bedrock from the bridge loading is smaller than its shear strength; and the shear displacement has a very low value, which indicates a safe bridge foundation.