Research Of Construction Technology About High Speed Railway Tunnel Located High Altitude Cold Regions

With the rapid development of our country’s infrastructure business and further promote the development of the western region, highway engineering, railway engineering and underground engineering in our country developed rapidly.Expresslythe development of high-speed railway is so fast in China,So a lot of long and big tunnel engineering located in the western region, go through the high altitude cold regions.Daban mountain tunnel belongs to class I risk is an second double high-speed rail’s controlling engineering. The engineering geologica and climatic conditionsof the tunnel located high altitude cold regionsare often poor.This thesis hopes to explore a similar conditions (ecological vulnerability, the relatively high elevation, frozen soil depth is relatively deep alpine area) the construction of high-speed railway tunnel is feasible in technology, reasonable economy, environmental friendly tunnel construction technology through to studying the Ventilation and oxygen technology in the construction, anti freezing technology, waterproofing and drainage measures, construction machinery.It can supplement the construction of high-speed railway tunnel construction technology in the alpine region plateau,For future similar plateau cold area the construction of high-speed railway tunnel provide certain construction technical support.1.The design of Daban mountain tunnel antifreeze bilge paramete.First of all is according to the Daban mountain tunnel engineering geological conditions to determine the tunnel cold tunnel in cold type for type III,Then the tunnel zone of ground temperature measurement to obtain first-hand information.And in the mouth of the cave of the tunnel segment, the measured tunnel radial inside certain limits of temperature and tunnel lining wall surface temperature within a certain depth range.Second, according to a tunnel under the condition of different depth by using the finite element software ANSYS to simulate the the size of the circle of frost heave and frost heaving force size,In according to the generalized the frost heaving force of frost heaving force level, and then to design the thermal insulation layer by these.Daban mountain tunnel in February and according to the measured temperature data of each part can know, shows that the calculation of insulation parameter is within the scope of safety factor.2.In the case of high altitude cold low pressure low oxygen makes grew up in the tunnel construction ventilation is relatively difficult, Daban mountain tunnel according to the different stages of construction ventilation organization has taken a different constructio n.Constraints for construction in the case of low oxygen oxygen diffuses scattered near measures to guarantee the construction constraints when it is near the workers demand for oxygen, And the organic combination of personal portable oxygen and oxygen supply of oxygen.Daban mountain tunnel ventilation is effective construction and organization management of oxygen supply to ensure the safety of tunnel during the construction of suitable for effective work environment.For the tunnel entrance section, before the excavation of surrounding rock in tunnel construction is in a state of frozen soil.The outside heat generated due to the construction, the surrounding rock near the constraints may be too hot melting phenomenon, thus affecting the stability of surrounding rock. In order to reduce the construction excavation for original frozen soil disturbance, especially construction ventilation cooling measures to eliminate the heat, keep the original thermodynamic state of original rock.By ideally the theoretical formula calculation and the use of Fluent software for numerical simulation of knowable guarantee merry at the end of the ventilation duct near the temperature to ensure the construction constraints and surrounding rock is in0℃or so, to avoid the construction of hot melting phenomenon.3.Tunnel freezing injury of the four basic factors for the temperature conditions, hydrological conditions, the conditions of surrounding rock, engineering measures, as long as the effective measures to cut off one of the factors can achieve good effect of anti freezing injury.In Daban mountain tunnel in addition to taking setting insulating from temperature freezing injury prevention, and take the effective waterproof and drainage system from hydrological conditions reduce frost damage.For groundwater development zone of low temperature water grouting to stop water, and use the protective drainage tunnel drainage can achieve better drainage effect. And using midasGTS to simulate the thermal discharge tunnel construction excavation for hole excavation, the effect of knowable drainage tunnel construction will not affect the main hole.4.Low oxygen low pressure makes the internal combustion machinery power can not meet the power rating in the Cold climate conditions of Daban mountain tunnel,In low oxygen combustion and internal combustion engine is not fully discharge a large amount of exhaust gas to increase the difficulty of the construction ventilation.So more adoption of more advanced and electric machinery equipment and reasonable supporting measures are used in the tunnel.From at the beginning of construction excavation, spray protector, bronchitis and inverted arch take large mechanical equipment not only improves the driving speed construction also saves manpower and material cost.