高压水工隧洞BFRP网格增强钢筋混凝土衬砌试验研究

为探究玄武岩纤维增强树脂复合材料网格(简称BFRP网格)对高压水工隧洞钢筋混凝土衬砌结构裂缝控制能力及承载能力的增强作用,进行了高压水工隧洞钢筋混凝土衬砌结构模型对比试验,试验采用真实高压水加载。通过对隧洞模型内壁环向变形监测,以及通过声发射系统对模型在加载全过程中的声发射信息监测,对比分析了BFRP网格对裂缝产生及扩展的影响。研究结果显示,与常规混凝土衬砌结构模型相比较,BFRP网格增强钢筋混凝土衬砌结构模型的极限承载力提高21%、宏观裂缝最大开度减少了68%、宏观裂缝空间分布更为分散;开裂前内壁环向拉应变增大了81%,开裂时的声发射绝对能量占加载过程中声发射总累积绝对能量的33.78%(前者为99.38%),主要破坏模式表现为韧性破坏。可见,BFRP网格可显著提高高压水工隧洞钢筋混凝土衬砌结构的裂缝控制能力和承载能力。

Experimental study on BFRP-grid reinforced concrete lining of high pressure hydraulic tunnel

In order to explore the enhancement effect from the basalt fiber reinforced polymer grid （BFRP-grid） on the cracking control capacity and bearing capacity of the reinforced concrete lining structure of the high pressure hydraulic tunnel， a comparative model experiment of the reinforced concrete lining structure of the high pressure hydraulic tunnel is carried out， in which the real high pressure water load is adopted. Through the monitoring on the circumferential deformation of the inner wall of the tunnel model as well as the monitoring on the acoustic emission （AE） information during the whole loading process from the relevant acoustic emission （AE） system， the effect from BFRP-grid on the crack generation and propagation is comparatively analyzed. The study result shows that the ultimate bearing capacity of the BFRP-grid reinforced concrete lining structure model is enhanced by 21% and the maximum opening of the macro-crack is reduced by 68% with a more dispersed spatial distribution of macro cracks， if compared with the conventional concrete lining structure model， while the circumferential tensile strain of the inner wall is increased by 81% before cracking and the AE absolute energy during cracking accounts for 33.78% of the total cumulative AE absolute energy during the loading （the former is 99.38%）with the main failure mode is the ductile failure. On the whole， BFRP-grid can significantly improve both the cracking control capacity and the bearing capacity of the reinforced concrete lining structure of the high pressure hydraulic tunnel.