汶川震区路肩墙抗震能力检算与震害机理分析

在汶川地震路肩墙震害调查基础上,根据设计图纸,按规范对路肩墙进行抗震能力检算和震害机理分析,获得以下结论:由于现行公路规范中有关规定表明地震工况时公路挡土墙稳定性验算不考虑车辆荷载,故按现行公路规范要求设计的挡土墙具有抵抗8度地震的抗震能力;9度地震烈度区路肩墙倾斜变形的原因是挡墙基底应力超过基底容许承载力值;10度地震烈度区路肩墙严重倾斜变形及出现毁坏现象的原因是抗倾覆稳定系数不满足规范要求和挡墙基底应力远远超过基底容许承载力值,碎石土基路肩墙还有抗滑动稳定系数不足的原因;现行公路规范中挡土墙稳定安全系数取值合理,在9度地震烈度区是适用的,并且可以延伸到10度地震烈度区。

Seismic Resistance Behavior Check and Seismic Damage Mechanism Analysis of the Shoulder Retaining Wall in Wenchuan Seismic Area

Seismic damage of the shoulder retaining wall was investigated in Wenchuan earthquake.According to design drawing and specification,the seismic resistance behavior of the shoulder retaining wall was checked and the seismic damage mechanism was analyzed.The conclusions were as follows: firstly,relevant regulations in the current highway codes showed that the vehicle load wasn't considered when checking the stability of highway retaining wall,therefore the retaining wall designed based on the current highway codes could resist 8 degree earthquake.Secondly,the reason of the shoulder wall's inclination distortion in 9 degree earthquake zone was that the foundation stress went beyond the bearing capacity.Thirdly,the cause of the shoulder wall's serious inclination distortion and collapse in 10 degree earthquake zone was that the toppling stability coefficient didn't satisfy requirements of the codes and the foundation stress went beyond the bearing capacity.Lastly,the stability safety factors value of retaining walls in the current highway codes was reasonable;it was applicable in 9 degree earthquake intensity zone and could be extended to 10 degree earthquake intensity zone.