隧道衬砌背后小尺寸空洞用聚氨酯注浆材料探究

Exploration of Polyurethane Grouting Materials for Small-Size Cavity behind Tunnel Lining

为探索适用于隧道衬砌背后小尺寸空洞的高性能注浆材料,制备了11组聚氨酯注浆材料,研究了其力学性能,提出了改进本构方程,并采用灰色关联进行综合评价.结果表明:1.16%~1.94%催化剂、3.80%~5.60%扩链剂可有效提高聚氨酯的力学性能;高相对分子质量多元醇的引入降低了聚氨酯的压缩强度和拉伸强度,却显著改善了其黏结强度;基于唯象模型提出的本构模型可准确表征聚氨酯的压缩变形;基于灰色关联得到聚氨酯的最佳配合比为异氰酸酯、相对分子质量为8000的多元醇及500的多元醇质量比25∶2∶23,催化剂掺量1.16%,扩链剂掺量1.94%,此配合比下聚氨酯综合性能最佳.

In order to explore high-performance grouting materials suitable for small-size cavity behind tunnel lining,11 groups of polyurethane grouting materials were prepared,and their mechanical properties were studied.An improved constitutive equation was proposed,and the grey correlation was used for comprehensive evaluation.The results show that 1.16%-1.94%of catalyst and 3.80%-5.60%of chain extender can effectively improve the mechanical properties of polyurethane.The introduction of high molecular weight polyols reduces the compressive strength and tensile strength of polyurethane,but significantly improves its bonding strength.The constitutive model based on the phenomenological model can accurately characterize the compressive deformation of polyurethane.Based on the grey correlation,the optimal mix proportion of polyols,isocyanates and a relative molecular weight of 8000 and 500 is 25:2:23,with a catalyst content of 1.16%and a chain extender content of 1.94%.Under this optimal mix ratio,the polyurethane has the best comprehensive performance.