【正文】 N tunnel longitudinal joints within the same section with more than 50% adjacent pipe joints staggered at least a meter. A. pipe roof construction method : Lofting accurate measurement personnel, marking the centerline and the vault out of its hole elevation, soil excavation reserved as a core pipe roof construction work platform Excavation footage of meters, after the end of excavation, artificial symmetrical on both sides of excavation (Commodities H) platform, level width of meters, meters high, as construction sets and pipe arch shed facilities drilling platform. Piperoof design position should be and it should be a good hole steel tube, grouting after playing nonporous tube steel, nonporous tube can be used as pipe inspection, Grouting quality inspection, drill vertical direction must be accurately controlled to guarantee the opening hole to the right, End each drilling a hole is a pipe jacking, drilling should always use dippass drilling pipe measuring the deflection, found that the deflection over design requirements in a timely fashion. Pipe joints using screw connection, screw length 1。), the direction parallel with the Central Line。 N Inclination : Elevation 1 176。 rather than single (double) PENDANTS Heading a high degree of mechanization, can accelerate the progress of the projects. The next heading advance excavation method (that is guided pit wall first arch) : This Act applies to Ⅱ , Ⅲ rock. in the soft ground tunneling, to be adopted next general guide advance excavation pit wall first arch Act. Its advantages are : Heading advance excavation, the use of proven geological conditions in advance to facilitate change in the method. Face to facilitate started procedures applicable to the labor arrangements for the use of small machinery and construction. The drawbacks : 河南理工大學(xué)本科設(shè)計(jì)畢業(yè)論文 20 The next section will guide small, slow construction and construction processes more, construction and management difficult. Unilateralarm pit Law : rock instability, the tunnel span larger, ground subsidence is difficult to control when using this method. Its characteristics are : a positive step and arms Heading Act advantages. Bilateral arm Heading law : in largespan shallow tunnels, surface subsidence require strict, especially poor rock used. Advantages of this method are : Construction of safe, reliable, but slow construction, high cost. main tunnel construction technology 1. Cave construction : （ 1） excavation slope around : Lofting total station measurements, the use of excavators from top to bottom, paragraph by paragraph excavation, not the amount of excavation or the end of next overlapping excavation, remove pits with the above may slump topsoil, shrubs and rock slopes, rock strata of slope excavation needs blasting, Discussion should focus mainly loose blasting. Also partial artificial finishing, when excavation and inspection slope of slope, if sliding and cracking phenomenon and slowing down due slope. （ 2） .Cheng Tungsupporting : Yang Brush Singapore Singapore after the pletion of timely inspection plate slope gradient, the gradient to pass the inspection, the system set up to fight time anchor, and the exposed bolt heads, hanging metal based work expansion and bolt welding into first overall. Linked work immediately after the pletion of shotcrete and repeatedly jet until it reaches the thickness of the design so far. （ 3） .as of gutter construction : Yang slope away from the groove 5 meters excavation ditch interception, interception gutter mainly mechanical excavation, artificial finishing, after dressing, 河南理工大學(xué)本科設(shè)計(jì)畢業(yè)論文 21 immediately masonry made of mortar and stones, and the floor surface with mortar. 2. Auxiliary construction : （ 1） A long pipe roof : Sets arch construction : construction Lofting, template installation, assembling reinforcement, the guidance of lofting 127 installation guide, concrete pouring. Pipe specifications : Heat Nazarbayev Seamless Steel Tube ￠ 108 mm and a thickness of 6 mm, length of 3 m, 6 m。 When u ↓, PE ↑. That is, rock deformation occurred, the release of some of the load (unloading), we should allow some extent rock 河南理工大學(xué)本科設(shè)計(jì)畢業(yè)論文 16 deformation, to give full play to rock the capacity for self. Is an economic support measures, the rock selfstability P=P0PE=Ku。 Spring in the event of deformation u, PE in the role they will be in equilibrium, assuming spring elasticity of K, were : P0=PE+Ku Discussion : (1) When u = 0, that is not allowed P0=PE rock deformation, is a rigid support, not economic。s and others. It works similar to the surface issues of the thinking is still widely used to. 河南理工大學(xué)本科設(shè)計(jì)畢業(yè)論文 13 Another theory of the 20th century made the 1950s the modern theory of timbering or rock for the theory. Its core content is : rock stability is clearly bearing rock to their own selfstability : unstable rock loss of stability is a process, and if this process in providing the necessary help or restrictions will still be able to enter the rock steady state. This theoretical system of representative characters Labuxiweici, MillerFeiqieer, Fenner Daluobo and Kashitenai others. This is a more modern theory, it is already out of the ground works to consider the ideas, and underground works closer to reality, the past 50 years has been widely accepted and applied. demonstrated broad development prospects. Can be seen from the above, the former theory more attention to the findings and the results of treatment : The latter theory is even more attention to the process and the control of the process, right from the rock for the full utilization of capacity. Given this distinction, which both theory and methods in the process, each with different performance characteristics. NATM theory is rock for the tunnel engineering p