加筋格宾新型组合支挡结构试验研究

Experimental Research on a New Kind of Compound Supporting and Retaining Structure with Reinforced Gabion Retaining Wall

通过对湖南省湘潭至衡阳西线高速公路第12合同段新型加筋土结构——加筋格宾组合式挡墙(加筋格宾+绿色加筋格宾结构)进行现场监测,得到了该加筋结构形式在填筑施工过程中的垂直土压力及水平土压力的分布规律、拉筋的变形规律及潜在破裂面形式。监测结果表明:加筋土挡墙垂直土压力沿筋材长度方向的分布呈现明显的单峰或双峰现象,实测垂直土压力一般均小于理论值;实测墙背水平土压力沿墙高呈曲线形分布,下墙中上部土压力很小,甚至接近零,而靠近底部1.5 m左右范围内的水平土压力最大;各层格宾网的应变随着填土荷载的增加而增加,随着时间的增加而有所降低。基于现场实测破裂面及不同规范所采用破裂面方法的对比分析,提出了改进型双折线破裂面。

Through on-site monitoring,a new type of reinforced support structure（compound reinforced gabion retaining wall,namely,gabion retaining wall and green reinforced gabion retaining wall） of 12th contract section of Xiangtan-Hengyang expressway in Hunan province,the distribution patterns of the vertical and lateral earth pressures of this reinforced structure during the filling construction process,the tied-reinforcement deformation and the shape of potential rupture surface,were obtained.The on-site monitoring result shows that（1） The vertical pressure of the reinforced soil retaining wall along the reinforcement is a distribution of single peak or double peaks and the measured values are less than the theoretical ones.（2） The measured lateral earth pressure of the reinforced wall back along the height is nonlinear.The lateral earth pressure at the upper part of the lower wall is very small even zero,but the value of the region near 1.5 m above the bottom is the maximum.（3） The tensile strain of each gabion mesh layer increases with load increase and decreases with time increase.Based on the measured potential rupture surface and comparative analysis of the potential rupture surfaces by the methods stipulated in different specifications,the improved double broken line potential rupture surface was put forward.