Inclined Shaft Parameters Research And Construction Technology In Highway Tunnel

With the development of highway construction in China, the scale of the long and large tunnel projects is increasing day by day, and the number of it is also growing up. More and more inclined shafts are built in order to meet the need of tunnel ventilation or speeding up the tunnel's construction progress. But there is lack of system research in the inclined shaft's design and construction technology at present, which are investigated through the investigation of existing projects in this paper. The main results obtained are as follows:First, twenty-nine inclined shafts are collected through the investigation of existing projects. On the base of it, this article summed up the methods of the inclined shaft construction, including the front well drill method and the back well drill method. The inclined shaft built by the front well drill method is from top to bottom on the ground, which is often used as the examples of domestic and international projects, and the construction technology is mature at present. On the contrary, the back well drill method is from bottom to top, which is suitable for the small inclined angle, but not for the large shaft section. Also, the advantages and disadvantages of the track-bound transportation and the trackless-bound transportation are compared:the former is convenient to acquire the ancillary equipment and shunt in the tunnel; the utter is convenient at the tunnel portal's condition, and the engineering process of which is quite simple. The trackless-bound transportation should be adopted in the incline shaft under permitting conditions. Besides, the methods of the intersection construction are summarized in three methods:ripping construction directly, ripping construction transitionally and the metro's full-envelope construction method. Generally, the intersection construction should choose the method of ripping construction directly; it should choose the method of ripping construction transitionally to increase the safety; while, the metro's full-envelope construction method usually is used at the large section.Secondly, the inclined shaft angle and the inclined section are studied, and the results are: different aspects should be considered when we choose the angles of the inclined shafts. The inclined shaft angle on the trackless-bound only needs to consider the transport equipment's climbing rate, which is designed to meet the half the largest climbing rate. The inclined shaft angle on the track-bound is mainly related to the selection of the elevator. The choice of the tunnel shaft angle should be within a certain reasonable limits, and the chosen of the inclined shaft is flexible depending on the specific project conditions of the tunnel. The determination of the inclined shaft cross section should be considered from the shape, the width and the height.Finally, in view of the high risk operation of the inclined shaft, this article establishes the quality and safety management system in order to ensure the construction normally and orderly, including the quality assurance measures and safety assurance measures. The quality assurance measures are explained from both the management and technical measures on the basis of the project quality assurance system. The safety assurance measures are explained from both the safety assurance system and safety technical requirements on the basis of the safety assurance system.In view of the situation of the inclined shafts set up increasingly, the results of this article would provide the guiding significance and reference value for the design and construction of the future inclined shafts.