加筋格宾组合式挡墙破裂面及承载力特性

Failure Surface and Bearing Capacity Character of Combined Reinforced Gabion Retaining Wall

为提出加筋格宾组合式挡墙(加筋格宾+绿色加筋格宾结构)破裂面及承载力公式,通过对湖南省湘潭至衡阳西线高速公路第12合同段加筋土实体结构进行现场试验监测,总结了各层拉筋应变变化规律,提出了基于简化破裂面转折点位置为H/3(H为墙高)的新折线型潜在破裂面,推导了该折线型破裂面在2种破坏模式下的墙顶部表面承载力通用计算公式;采用极限平衡法,讨论了拉力破坏下其极限承载力公式,统一了0.3 H简化破裂面和朗肯破裂面形式下的承载力计算公式,并与4种规范加筋土典型破裂面进行了比较分析。结果表明:采用该折线型破裂面计算,比公路规范和BS8006规范安全,比铁路规范经济;双绞合六边形钢丝网加筋为拉力破坏,试验结果与计算结果相吻合。

In order to put forward the failure surface and bearing capacity formula of combined reinforced gabion retaining wall composed of the reinforced gabion retaining wall and green reinforced gabion retaining wall,the field test monitoring on a new type of reinforced support structure in the actual slope protection engineering of the 12th contract section of Xiangtan-Hengyang West Line Expressway in Hunan Province was carried out.The strain distribution laws of the tied-reinforcement in different layers were obtained.Based on the new broken line potential failure surface whose kickpoint of the simplified failure surface is H/3（H is the height of the retaining wall）,the calculated formula of bearing capacity of the top surface of retaining wall under two failure modes of the broken line failure surface was deduced.Using the limit equilibrium method,the formula of ultimate bearing capacity under the condition of tensile failure was thoroughly discussed and this formula unifies the bearing capacity formula of the 0.3H simplified failure surface and that of the Rankine failure surface. The new broken line failure surface was compared with four typical failure surfaces.Results show that it is safer to calculate the failure mode by the broken line simplified failure surface than by the highway specification and BS8006,and it is more economic than the railway specifications. The failure mode of the reinforced earth retaining wall with double-twisted hexagonal steel wire mesh is the tensile failure mode.Test results agree well with calculated results.