进水塔塔背回填抗震设计优化研究与动态响应分析

为分析塔背不同回填材料与不同回填厚度对进水塔动态响应的影响,建立6种回填材料与4种回填厚度相互组合下的数值试验模型,对进水塔进行动力分析。对比进水塔关键部位的应力与位移发现:回填材料的不同对塔背与回填交界区域应力有一定影响,石渣回填时,此区域应力最大值有很大减小,接触面应力分布状态也发生了变化;回填厚度对塔顶位移的影响不大。根据数值试验的计算结果与分析规律,合理使用石渣回填,设计了一种新的回填型式。此型式下塔背与回填交界区域不在为集中应力发生的部位;接触面最大应力大幅减小,相同部位的应力值减小;大应力区位置向下偏移,且区域变大、变宽,说明新回填型式改善了进水塔结构的应力状态,对其安全很有利。将提出的回填方法应用于某泄洪洞进水塔结构中,对比分析了新回填型式与原回填型式两种情况下此进水塔塔背与回填交界角点应力时程曲线、塔背与回填接触面应力云图与损伤云图。结果表明新回填型式下进水塔与回填接触面的动态响应得到了很大改善,该方法对进水塔结构的抗震与安全具有重要意义,可供类似工程借鉴。

Seismic design optimization and dynamic response analysis of intake tower backfill

In order to analyze the effects of different backfill materials and different backfill thickness on the dynamic response of intake towers, we set up a numerical test model that combined 6 types of backfill materials and 4 types of backfill thickness, and conducted dynamic analysis of the intake tower. When the rock ballast was filled, the maximum stress of the area was greatly reduced, and the stress distribution of the contact surface was changed; the thickness of backfill had little influence on the displacement of the top of the tower. Based on the calculation results and analysis of the numerical test, a new type of backfill was designed with rational use of rock ballast backfill. For this type, the junction between the tower and the backfill was not in the position of the concentrated stress. The maximum stress of the contact surface was greatly reduced, and the stress value of the same area was reduced. The large-stress area shifted downwards, and the area became larger and wider, indicating that the new type improved the stress state of the intake tower structure, and was beneficial to the safety of the intake tower. The proposed method was applied to the structure of a water intake tower in a flood discharging tunnel. Comparison was made between the new and original backfill types in terms of the stress time-history curve of the junction between the intake tower back and backfill, as well as the stress nephogram and damage nephogram of the contact surface between the intake tower back and backfill. The results showed that the dynamic response of the contact surface between the intake tower and backfill was greatly improved by the new type of backfill. This backfill method is of great significance to earthquake resistance and safety of intake tower structures, and can be used as reference for similar projects.