岩溶区隧道新型绿色注浆材料试验研究

Experimental Study on New Green Grouting Material of Karst Area Tunnel

研究目的:为解决传统注浆材料难以同时满足岩溶区隧道注浆止水、回填及加固要求的问题,研究一种由硫铝酸盐水泥、普通硅酸盐水泥、甲酸钙、聚羧酸、瓜尔胶配制而成,适用于岩溶区隧道注浆的新型绿色注浆材料(Green Grouting Material, GGM)。通过正交试验探究各组分对GGM浆液基本性能的影响,开发一种模拟岩溶区动水注浆的装置对最优配比下的GGM浆液进行特性测试,得到不同水流速、模拟环境下注浆材料的动水留存率,分析GGM材料适用性并得到不同环境下动水留存率关于动水流速的回归方程。研究结论:(1)当硫铝酸盐水泥水灰比为0.33,普通硅酸盐水泥掺量20%,甲酸钙掺量3%,聚羧酸掺量0.3%,瓜尔胶掺量0.3%时,GGM的主要性能最优,相较于硫铝酸盐水泥和普通硅酸盐水泥,最优配比下的GGM具有明显更优的动水留存率;(2)GGM浆液在动水流速为0.4 m/s的富水岩溶区空腔环境、断层破碎带、富水砂卵石地层、富水砂层中的动水留存率分别为58.6%、68.36%、64.72%、87.29%,充填堵水效果较显著,满足一般注浆工程需求;(3)GGM材料具有机械强度高、凝结时间快、流动度良好、动水留存率高等优点,是一种较为理想的富水岩溶区隧道注浆材料;(4)本研究成果可为岩溶区隧道注浆止水加固提供参考和借鉴。

Research purposes:To solve the problem that traditional grouting materials can hardly meet the requirements of water stopping,backfilling and reinforcement of tunnel grouting in karst areas at the same time,a new green grouting material(GGM)consisting of sulphate aluminate cement,ordinary silicate cement,calcium formate,polycarboxylic acid and guar gum is formulated and suitable for tunnel grouting in karst areas.The effect of each component on the basic properties of GGM slurry was investigated through orthogonal tests,a device was developed to simulate dynamic water grouting in karst areas to test the properties of GGM slurry at optimal ratios,the grout retention ratio(GRR)was found for different water flow rates and simulated environments,and the suitability of the GGM slurry was analyzed and the regression equation of GRR on the dynamic water flow rate was obtained for different environments.Research conclusions:(1)When the water-ash ratio of sulphate aluminate cement is 0.33,ordinary silicate cement is 20%,calcium formate is 3%,polycarboxylic acid is 0.3%,and guar gum is 0.3%,the main performance of GGM is optimal.Compared with sulphate aluminate cement and ordinary silicate cement,GGM under the optimal ratio has significantly better dynamic water retention rate.(2)The dynamic water retention rate of GGM slurry in the cavity environment,fault fracture zone,water-rich sand pebble formation and water-rich sand layer in the dynamic water flow rate of 0.4 m/s is 58.6%,68.36%,64.72%and 87.29%,respectively,and the water flling effect is significant to meet the needs of general grouting engineering.(3)The CCM material has the advantages of high mechanical strength,fast setting time,good flow degree and high dynamic water retention rate,which is a relatively ideal tunnel grouting material in the water-rich karst area.(4)The research results can be used as a reference for grouting and water stopping reinforcement for tunnels in karst areas.