土遗址裂隙加固桩-浆协同效果与机制研究

研究表明以生石灰为掺料的浆液与土遗址兼容性良好，并且发现在此浆液中添加微型石灰桩能够更好消除浆-土界面的干缩分异的现象。为探究桩-浆协同作用下裂隙的加固效果与机制，通过开展单独注浆工艺和宽径比（裂隙宽度与石灰桩直径的比值）为1.5、2.0、2.5和3.0桩-浆协同工艺下室内遗址土裂隙注浆实验。浆液养护63天后，首先对裂隙两侧等距土体的宏观性质指标（贯入阻力、密度、液塑限和颗粒组成）进行测试；而后通过扫描电子显微镜、比表面积（SSA）和阳离子交换量（CEC），以及基于孔隙率变化建立的强化变量对裂隙注浆后加固效果进行定性和定量联合分析。结果表明：桩-浆协同作用下宽径比小于2.5时对裂隙的加固效果均优于单独注浆条件，宽径比为2.0时效果最佳；宽径比大于3.0时加固效果弱于单独注浆条件。而结果所反映的本质是分属于石灰桩和浆液的膨胀和离子迁移对裂隙两侧土体的挤密和团聚作用不是简单的线性叠加，而是当宽径比超过2.0时出现浆液对石灰桩的挤密和团聚作用产生明显抑制反馈。

Researches on Synergistic Effect and Mechanism of Pile-slurry for Reinforcement of Fissure Grouting in Earthen Sites

Researches show that the slurry with quick lime as admixture is well compatible with earthen sites, and it is found that adding the micro-lime piles into this slurry can better eliminate shrinkage differentiation phenomenon of the slurry-soil interface. In order to explore the reinforcement effect and mechanism of fissure, fissure grouting of indoor earthen sites was carried out under single grouting technology and pile-slurry synergistic reinforcement technology with the width-diameter ratio of 1.5, 2.0, 2.5 and 3.0 (ratio of crack width to lime pile diameter). After curing for 63 days, the macro-properties (penetration resistance, density, liquid plastic limits and particle composition) of equidistant soil on both sides of the fissures were firstly tested. Then the reinforcement effects of the soil on both sides of fissure were qualitatively and quantitatively analyzed by scanning electron microscopy, the specific surface area, cation exchange capacity and the reinforced variables established on the change of porosity. The results showed that the reinforcement effect was better than that of single grouting when the width to diameter ratio is less than 2.5, was the best when the width to diameter ratio is 2.0, and was weaker than that of single grouting when width to diameter ratio is more than 3.0. The essence reflected by the results is that the compaction and agglomeration of soil on both sides of fissures caused by the expansion and ion migration of lime pile and slurry are not a simple linear superposition, but when the ratio of width to diameter is more than 2.0, the slurry will obviously inhibit the compaction and agglomeration of lime pile.