垂直节理发育红层软岩路堑边坡工程病害分析

红层软岩在我国广泛分布,其力学性质较差,具有强度低、亲水性强、遇水易软化、易崩解等特性,极易产生工程病害。文章针对垂直节理发育的红层典型软岩,通过具体工程病害分析,得出以下主要结论:(1)垂直节理裂隙发育的红层软岩,路堑开挖后形成临空面,节理裂隙变大,大爆破施工更加重裂隙的张开程度,因此,距离路堑坡面2～3 m范围内,岩体宜采用机械开挖或小爆破施工;(2)严禁边坡采用大拉槽施工,严格执行"分级开挖分级防护",不宜在雨季进行边坡开挖和防护施工;(3)完善临时和永久排水系统,坡面防护宜采用易形成防排水功能的措施,宜在路堑坡脚设置预加固桩,在坡面设置框架锚杆加固防护。

Disease Analysis of Vertical Joint Development Red Soft Rock Cutting Slope Engineering

Red layer soft rock is widely distributed in China, its mechanical properties are poor, it has the characteristics of low strength, strong hydrophilicity, easy to soften in water and easy to disintegrate and so on. It is very easy to produce engineering diseases. In view of the typical soft rock of the red layer in the vertical joint development, the following main conclusions are obtained through specific engineering disease analysis:(1) the red layer soft rock developed by the vertical joint fracture, after cutting excavation, the hollow face is formed, the joint fissure becomes larger, the large blasting construction increases the crack opening degree, within the range of 2~3 to the cutting slope, Mechanical excavation or small blasting construction is adopted;(2) the slope is strictly prohibited to use large troughs for slope construction, and strictly implement "graded excavation and graded protection". It is not suitable for slope excavation and protection construction in the rainy season;(3) perfect temporary and permanent drainage system, slope protection adopts protective measures which are easy to form drainage function and should set pre-reinforced piles at the foot of the cutting slope and frame bolts on the slope for reinforcement and protection.