针对深部裂隙岩体水泥基注浆加固后由于材料自收缩性造成浆岩界面松弛及充填不满问题，提出了裂隙岩体自应力注浆加固概念。通过外加剂促使浆液结石体在约束空间内体积膨胀，当膨胀剂掺量超过补偿水泥自收缩的临界掺量时，结石体体积膨胀除补偿水泥基材料自收缩外，在裂隙岩体的约束空间内能够对裂隙壁产生一定的膨胀应力，膨胀应力能够增大浆岩界面的挤压作用，改善岩体的约束受力状态。通过超细硅质浆液膨胀率测试、约束浆液结石体强度试验、约束浆液结石体微观结构分析等研究自应力浆液加固机理，通过裂隙岩体注浆加固试验验证自应力浆液的加固效果。结果表明：随着膨胀剂掺量逐渐增大，浆液纵向自由膨胀率和约束浆液结石体强度均呈先增大后减小的趋势，10%膨胀剂掺量浆液膨胀效果明显优于其它膨胀剂掺量。硅质自应力浆液结石体的脆性增强，弹性变形延长。10%膨胀剂掺量硅质自应力浆液结石体呈大颗粒状，颗粒相互搭接，形成网状结构，有利于结石体强度发挥，其密实性明显优于普通浆液结石体。25%膨胀剂掺量浆液结石体晶体大小不均，颗粒空隙较大，其密实性明显弱于10%膨胀剂掺量自应力浆液结石体。自应力注浆砂岩的峰值强度和弹性模量分别为普通注浆砂岩的1.110倍和1.043倍，自应力注浆加固砂岩的峰值应变略小于普通浆液加固砂岩。自应力注浆加固裂隙砂岩的效果明显优于普通注浆，结石体形变模量增大，结石体与砂岩裂隙壁之间的摩擦力提高。

In order to overcome the problem of grout-rock interface dissatisfaction due to self-shrinkage of materials in deep fractured rock masses strengthened by cement-based grouting,this paper proposed the concept of self-stress grouting and strengthening of fractured rock masses.The admixture promotes the volume expansion of the slurry stone body in the confined space.When the content of swelling agent exceeds the critical content of compensating cement self-shrinkage,in addition to compensating for self-shrinkage of cement-based materials,the volume expansion of the slurry stone can generate a certain expansion stress on the fracture wall in the confined space of the fractured rock mass.The expansion stress can increase the compression effect of the slurry-rock interface and improve the constrained stress state of the rock mass.The self-stress slurry reinforcement mechanism was studied by the test of the expansion rate of ultrafine siliceous slurry,the strength test of confined slurry stone,and the microstructure analysis of confined slurry stone.The reinforcement effect of self-stress slurry was verified by grouting reinforcement test for fractured rock mass.The results showed that with the increase of the expansion agent content,the longitudinal expansion rate of the slurry and the strength of the confined slurry stone increased first and then decreased.The swelling effect of 10% swelling agent was obviously better than other swelling agents.The siliceous self-stress slurry stone had increased brittleness and prolonged elastic deformation.The siliceous self-stress slurry stone with 10% expansion agent content had large particles.The particles overlapped each other to form a network structure,which was conducive to the strength of the slurry stone.Its compactness was obviously better than that of ordinary slurry stone.The self-stress slurry stone crystals with 25% swelling agent content was uneven.The particle gap was large,and its compactness was obviously weaker than the self-stress slurry stone with 10% swelling agent content.The peak strength and elastic modulus of self-stress grouting reinforced sandstone were 1.110 and 1.043 times of ordinary grouting reinforced sandstones,respectively.The peak strain of self-stress grouting reinforced sandstone was slightly smaller than that of ordinary grouting reinforced sandstone.The effect of self-stress slurry to strengthen fractured sandstone was significantly better than that of ordinary slurry.The deformation modulus of the slurry stone and the friction between the slurry stone and the sandstone were increased.The research results had a certain guiding significance for grouting reinforcement in deep rock mass.

1 裂隙岩体自应力注浆加固原理

2 硅质浆液膨胀率与约束结石体强度试验

   2.1 超细硅质浆液膨胀率试验

   2.2 超细硅质自应力浆液强度试验

3 超细硅质自应力浆液结石体微观结构

4 裂隙岩体自应力注浆加固应用

   4.1 试验方法

   4.2 裂隙砂岩单轴压缩试验

5 结论与展望