中文摘要：

喀喇昆仑公路堰塞湖改线段是中巴公路受地质灾害影响较重的一段,该段的隧道多是覆盖大面积松散崩坡积体的浅埋偏压隧道,隧道进洞施工难度大。以公路改线段2号隧道为例,对隧道入口洞顶松散崩坡积体进行注浆加固,结合现场监测,研究隧道加固处治的效果。结果表明,洞口处坡积体松散破碎,土石混杂,级配不良,稳定性差,需加固处理;进行注浆加固区洞顶沉降相比非加固区明显减小,水泥＋水玻璃＋石膏是最佳固化剂组合,且水灰比越大,注浆管径越大,加固效果越优;注浆加固是通过固化剂水化生成氢氧化钙、水化硅酸钙结散体作用及钙矾石膨胀填孔作用,提高松散崩坡积体整体性和强度,增强其抗变形能力。

英文摘要：

The realignment section at the dam lake on Karakoram highway is heavily affected by geological disasters on the China-Pakistan highway,most of the tunnels in this section are shallow buried and unsymmetrical pressure tunnel and covered with a large area of loose colluvial deposits,the construction of tunnel outlet is in great difficultly.Relying on the No.2# tunnel on the realignment section,the loose colluvial deposits on tunnel entrance is consolidated by grouting,and combining with on-site monitor,the effect of reinforcement for tunnel is studied.The results show that：the colluvial deposits at tunnel entrance are loose and broken,mixed with earth and rock,poorly graded and with poor stability,where needs reinforcement;the tunnel outlet settlement of reinforcement area is significantly reduced compared to non-reinforcement area,cement＋water-glass＋ gypsum is the best combination of stabilizer,and the greater the water-cement ratio,the larger the diameter of grouting pipe,the reinforcement effect is more excellent;grouting reinforcement is realized by cementation of Ca（OH）2 and calcium silicate hydrate（CSH）and expansion filling-pore effect of Ettringite（AFt）,which can improve the integrity and strength of loose colluvial deposits,and enhance its resistance to deformation.