高昌故城内城墙墙体土遗址动力响应分析

Dynamic Response Analysis of Inner Soil Wall Ruins in Ancient Gao⁃chang City

对高昌故城内城墙墙体进行现场脉动测试,获取土建筑遗址的频谱特性及其自振频率,分析高昌故城内城墙不同部位速度放大效应,研究其在地震荷载作用下的动力响应特征,明确墙体薄弱部位已有加固措施的防护效果。结果表明:高昌故城内城墙的速度放大倍数约1.5~2倍,与地脉动测试结果大致吻合;内城墙自底部至顶部,速度、位移响应均逐渐增大,二者在墙体凹陷处的表现不同,前者相对降低、后者量值最大;内城墙凹陷及洞穴处加固前后应力分布变化明显,应力集中部位不再处于墙体薄弱部位,墙体加固效果良好。所得结果可为高昌故城墙体抗震加固防护提供参考依据。

Through the in-site pulsation test on the inner wall of ancient Gaochang City,the spectrum characteristics of the earthen architecture sites were measured.The self-vibration frequency was ob⁃tained by the spectrum diagram,and the velocity amplification effect at the middle and bottom of the inner wall of ancient Gaochang City was analyzed.Dynamic response analysis under seismic loading was carried out.The results show that the velocity amplification at the middle and bottom of the inner wall of ancient Gaochang City is about 1.5-2,which is roughly consistent with the pulsation test re⁃sults.From the bottom of the inner wall to the top,the response velocity and corresponding displace⁃ment gradually increase.But the velocity decreases in the cavity in the wall while the displacement reaches its maximum at the same site.The distribution of stress changes greatly after the reinforce⁃ment treatment of the wall defect,the maximum stress point transfers from the weak part to the top and bottom of the wall,illustrating a good reinforcement effect.Further damage to the cultural relics of the soil sites can be avoided through the reinforcement of the wall.This research provides a refer⁃ence for the strengthening of ancient Gaochang City.