不同地基模型下梁式基础的统一计算方法

通过对三弯矩方程解连续梁的方法在弹性地基梁计算上的扩展,提出了半无限大弹性体、有限压缩层和温克勒三种地基模 型下梁式基础精确计算的新方法,使不同地基模型下梁式基础的计算达到了统一。文中推导得出了梁与地基共同工作的总柔度矩阵, 建立了用力法计算弹性地基粱的统一方程。且给出了在不同地基模型下利用该方程计算地基梁时总柔度矩阵的构建方法,进而给出 了采用本方法计算梁式基础的计算步骤。该算法可在任意基于地基是线弹性变形体假设的地基模型下使用。

Impact coefficient and reliability of mid-span continuous beam bridge under action of extra heavy vehicle with low speed

To analyze the dynamic response and reliability of a continuous beam bridge under the action of an extra heavy vehicle, a vehicle–bridge coupled vibration model was established based on the virtual work principle and vehicle–bridge displacement compatibility equation, which can accurately simulate the dynamic characteristics of the vehicle and bridge. Results show that deck roughness has an important function in the effect of the vehicle on the bridge. When an extra heavy vehicle passes through the continuous beam bridge at a low speed of 5 km/h, the impact coefficient reaches a high value, which should not be disregarded in bridge safety assessments. Considering that no specific law exists between the impact coefficient and vehicle speed, vehicle speed should not be unduly limited and deck roughness repairing should be paid considerable attention. Deck roughness has a significant influence on the reliability index, which decreases as deck roughness increases. For the continuous beam bridge in this work, the reliability index of each control section is greater than the minimum reliability index. No reinforcement measures are required for over-sized transport.

基坑支护桩与顶部圈梁共同工作的简化分析方法

本文试用简化方法分析矩形平面基坑悬臂式支护桩与压顶圈梁共同工作的受力变形机理,提出桩梁临界刚度比的概念,并导出其计算公式,以三点位移协调法导出圈梁三点的荷载、弯矩和挠度近似计算公式,为基坑支护工程提供有价值的参考依据。

矩阵力法计算网格梁的探讨

本文探讨了矩阵力法计算网格梁的方法 ,推导了计算公式 ,阐述了具体的计算步骤。