水平旋喷注浆试验装置研制及初步应用OA

[Objective]In view of the poor reinforcement effect of conventional grouting in soft and fractured strata of deep-buried tunnels and the lack of an indoor horizontal jet grouting test device,this study aims to develop a horizontal jet grouting test device capable of simulating certain in-situ stress conditions and to conduct a preliminary application study.[Methods]The device consisted of four parts:a grouting system,a jet grouting system,a loading system,and a data acquisition and control system.The loading system provided a maximum loading capacity of 120 t,simulating a formation stress of 1.2 MPa.The jet grouting system enabled stepless adjustment and precise control of rotational speed of 0~50 rpm and extension/retraction speed of 0~50 cm/min.The grouting system supported accurate metering and 1∶1 mixing of two-component polymer materials.With the ultracataclasite stratum in Xianglushan Tunnel of the Central Yunnan Water Diversion Project as the engineering background,a preliminary test was conducted using polymer grouting material under conditions of an overburden surrounding rock pressure of 1 MPa,a grouting pressure of 20 MPa,a rotational speed of 15 rpm,and an extension/retraction speed of 10 cm/min.[Results]The results showed that the device operated stably,the systems exhibited good coordination,and an elliptic cylindrical jet-grouting pile was successfully formed.The cross section of the jet-grouting pile exhibited a gradient structure consisting of a replacement zone,a mixed zone,and a permeation zone from the inside to the outside,and the core samples exhibited typical resilient softening characteristics with high residual strength.A three-level framework for resilient reinforcement of surrounding rock was proposed,comprising material-level,component-level,and system-level resilience.The mechanism of resilient reinforcement by which polymer jet-grouting piles achieved coordinated energy dissipation across multiple zones through their gradient structures was discussed.[Conclusion]The development of the device provides a technical means for the laboratory evaluation of the reinforcement effect of horizontal jet grouting in soft and fractured strata of deep-buried tunnels.It has practical engineering value and scientific significance for optimizing jet-grouting process parameters and developing resilient reinforcement theory.