Advanced Materials Research Vols. 594-597

Abstract: The paper pointed out a comprehensive advanced geological prediction method combining geological radar with advanced horizontal borehole according to the highway double-arch tunnel construction method in karst area, and had a successful application in the highway double-arch tunnel construction in karst area in Guangxi Province. It was proved in the tunnel construction that the prediction effect of the comprehensive geological prediction method was ideal.

Abstract: Analysis of the surrounding rock stress distribution of neighborhood tunnel by using numerical simulation. Based on Cullen-Moore Theory, build a mathematical model of 1st principal stress σ1, 2nd principal stress σ2, internal friction angle φ, and cohesion c, then, make a expression of tunnel spacing safety factor A. Analysis a real tunnel project and evaluate its surrounding rock stability with safety factor A as the index. Propose an analysis method of judging the rationality of tunnel spacing.

Abstract: In tunnel construction process, Because monitoring points setting always get behind with tunnel heading and occurred space effect which induces displacement loss and affects the monitoring accuracy. Studying tunnel space affect has important meaning to the monitoring data analysis. The paper takes Dalian Metro Station as research back ground, adopted three dimensional elastic-plastic numerical test method and carried out the excavation process simulation. Studied the convergence displacement and sedimentation displacement variation regulation along with the distance to tunnel heading face. The simulation results state that the nearer to the tunnel heading, the displacements of surrounding rock are smaller. Analyzed the ratio of displacement loss induced by space effect and amended the monitoring displacements of Dalian Metro Station.

Abstract: As one of national important engineering, South-to- North Water Transfer middle line crossed the Beijing subway route 1. Various controlling technologies of deforming were applied during construction of water tunnel in order to control the deformation of the existing subway tunnel. At the same time, automatic monitoring technology was applied too. By the system analysis of monitoring data and controlling measures, the rule of structure deformation is concluded and the validity and fitness of controlling measures are validated. At last, it is useful experience for similar engineering.

Abstract: A kind of geological disasters such as fault and water gushing often occurs during the informational construction of deep super long tunnel, which brings momentous disaster and economic loss to construction safety, so the precise and immediate advance forecast to the situation of fault and water gushing has an important theoretical significance and practical value. The theory of geological survey method, TSP(tunnel seismic prediction) method and GPR(ground penetrating radar) method are summarized and analyzed, forecast geological prediction process for fault and water gushing in deep-buried super long tunnel is formulated with the combination of the three methods. Then a deep super long road tunnel named Da Xiang Ling is detected by using the process synthetically, which gains good prediction results. It has a certain guiding significance to similar projects.

Abstract: The construction process of water conveyance tunnel is complex and stochastic under the karst geological condition. Aiming at analyzing the construction process under this special condition, a simulation modeling method of water conveyance tunnel construction is presented. Through demonstrating the simulation analysis and predicting the schedules in a real case study of a water conveyance tunnel, this method is proved advanced and intuitive for formulating and analyzing the construction schedules under the karst geological condition.

Abstract: Based on the engineering that shield machine’s passing through a vertical shaft in urban rail transit construction, two methods are proposed according to the engineering geology and construction organization and finite element model is established to simulate the real situation. After the technical analysis and safety analysis of the two methods, the recommended method is given, also given are the corresponding safety measures and construction procedure. The success of this engineering proves that this analysis is reasonable and the safety measures are worth of referring to.

Abstract: Abstract. Due to the complexity of shield tunnel construction process, some segments may be damaged. To obtain the cause of segmental damage, stress acting on segments is needed to be analyzed. In this paper, the damage characteristics of a shield tunnel segments were summarized firstly, then a 3D discontinuous model considering of shield tunnel segments and bolts was established to analyze the stress characteristics of segments during construction. The study has manifested that squeezing of segmental bump tenon, thrust force and its obliquity, uneven jack thrust are the main causes of segmental damage during the shield tunnel construction.

Abstract: In order to reduce the adverse effect of the blasting vibration velocity to residents in the urban subway blasting excavation construction, and made it meet the requirements of design, based on the stress concentration effect of empty hole, carried out the research of middle empty hole in parallel hole cut blasting. Adopted the technology of middle empty hole in parallel hole cut blasting, by measuring the blasting vibration velocity, the utilization rate of borehole, the half eye tracking rate, and so on, the results showed that the blasting vibration velocity of cut blasting was 0.69cm/s, the blasting vibration of expansion slot blasting was 1.27cm/s, the borehole utilization was 90%, and the half eye tracking rate of periphery holes was 90%. The test results showed that this technology could effectively reduce the blasting vibration under the residential areas in blasting excavation, the effective experiences could be used in the similar projects.

Abstract: Aiming at the problem of a difference between the TBM advance speed estimated by the NTNU and CSM model, and the actual advance speed, a quantitative analysis is carried out in the paper. Combining the experimental results of the uniaxial compressive test with the rock mechanics experiment system TAW-2000 and MTS815, the paper quantitatively characterizes the main parameters including the rock compressive strength, elastic modulus, abrasiveness, and the thrust force of cutterhead, corresponding to TBM advance speed by using the method of quantitative analysis of multi-factors. Moreover, the relationship between the TBM advance speed and the parameters was established. It is indicated that higher rock strength, abrasion and a smaller thrust force of cutterhead are reasons resulting in a lower TBM advance speed.