In the design of Jiazhuqing tunnel, a series of safety measures were taken, such as pre-pumping, pre-drainage, sealing the pit wall, strengthening ventilation, eliminating fire source, spray cleaning and reducing coal dust. In order to reduce the ventilation resistance, make as much fresh air as possible into the tunnel and reduce the gas concentration, a parallel pilot tunnel and two inclined shafts are set in the tunnel entrance work area and the inclined shaft work area, and strong roadway ventilation is formed through the suction effect of large fans. After ventilation, during construction, the gas concentration in the heading face is not more than 65438 0%, the gas concentration in the return air roadway (parallel pilot tunnel) is not more than 0.75%, and the wind speed in any part of the tunnel is not less than 0.5m/s ... In order to prevent the gas from gathering and staying in the corners of the roadway, feng shui sprayers are arranged in the heading face to disperse gas and reduce coal dust. In the construction of Jiazhuqing tunnel, the method of "one exploration and two surveys, three rows and four inspections, vibration blasting and safe refuge" was adopted. Outburst prevention measures.
Nanning-Kunming Railway is towed by electric locomotive, and high voltage arc sparks often occur between pantograph and catenary. In addition, the friction sparks produced by train brake shoes and the open flames produced by passenger car dining cars are all dangerous fire sources of gas. For a high gas tunnel like Jiazhuqing, although a series of sealing measures have been taken on the lining structure, considering that there are probably some imperfections in design and construction, some gas will leak into the tunnel and accumulate gradually. Because the length of Jiazhuqing tunnel is nearly 5 kilometers, natural ventilation is not enough to dilute and remove moles. Over time, if the cumulative gas concentration exceeds 0.5%, it will threaten traffic safety. Therefore, the inclined shaft in the middle of the tunnel is used for mechanical ventilation, and gas probes are set at the vault at regular intervals in the tunnel. When the central control room finds that the Nevas concentration in the tunnel rises to a dangerous value, start the inclined shaft fan for ventilation. The tunnel started on 1993 and was laid on1May 1996 1 1.
Small dictionary-qi. The gas in the stratum is the gas produced by the decomposition of ancient underground organic matter. The main component of gas is methane, which is a colorless, odorless and odorless combustible gas. In the standard state, 1 m3 gas weighs 0.7 16 kg, which is lighter than air and often gathers at the top of roadway. Under normal circumstances, when the gas concentration in the air is 5 ~ 16%, it can cause an explosion when it meets an open flame. When the gas concentration is 9.5%, the explosion power is the largest. When the gas concentration exceeds 16%, it loses its explosiveness, but it can still burn in case of fire. It is worth noting that when the air contains coal dust, the gas concentration can explode when it reaches 3%. Because gas exists in the coal seam at a certain pressure, when the roadway is excavated, the pressure suddenly decreases. In a very short time (a few seconds), a large number of gas and pulverized coal rocks are suddenly ejected, the number of which can reach dozens of tons, causing the roadway to collapse and drown, causing casualties, which is called "coal and gas outburst". It can be seen that gas is the most dangerous "enemy" in tunnel construction. The tunnel is located in Bantao Township, tianlin county City, Guangxi Zhuang Autonomous Region, with a total length of 9392 meters. The tunnel crosses the Kyubi no Youko Mountains, the watershed between Youjiang River and Nanpanjiang River. The mountains in the area are continuous, with ups and downs, steep slopes and deep valleys. This area belongs to the subtropical humid monsoon climate, and the trees in the mountains are evergreen all year round, with flowers and fruits constantly. Every winter, the rice flowers all over the mountains are in full bloom, white and fragrant, hence the name Mihualing.
The geology of the mountain through which the tunnel passes is complicated. There are 3 main faults threatening the tunnel, 6 minor faults 16, 6 folds and 10 water storage zones, among which 4 water-rich zones may burst into water and mud. The day and night water inflow of the tunnel is17000m3. The plane of the tunnel line is S-shaped, and there are curves at the entrance and exit. The length of the entrance curve into the tunnel is 258 meters, and the radius of the curve is 1000 meters, accounting for about 6% of the whole tunnel. The two curves are mainly limited by the stations at both ends of the tunnel and the terrain conditions. Bantao stood in front of the tunnel entrance, and Genlong stood behind the tunnel exit. The tunnel supporting structure is designed according to NATM principle. Curved wall composite lining section is adopted. Class Ⅱ and Ⅲ surrounding rock sections are fully enclosed by curved wall inverted arch, and Class Ⅳ surrounding rock sections are not provided with inverted arch. The bottom of the tunnel is reinforced with reinforced concrete floor to improve the stress state of the supporting structure, prevent mudstone from softening under the repeated action of the train and avoid diseases at the bottom of the tunnel. The water inflow of this tunnel is relatively large. Drainage is the main design, and the combination of drainage and blockage is adopted. For Class II surrounding rock sections that may burst with water and mud, full-face long conduit grouting is used to block water before excavation. The tunnel supporting structure adopts the way of blocking up and draining down to control water, that is, the arch is equipped with non-woven fabric and polyethylene waterproof board in the secondary supporting room, the wall is equipped with blind ditches at intervals, and the tunnel is equipped with bilateral drainage ditches in the longitudinal direction, so as to make the water flow smooth and avoid the water from endangering the bottom of the tunnel and causing diseases. The key project of this tunnel is the three main faults in the middle exit section of the tunnel. The total length of fault fracture zone and influence zone is 575 meters, which is equivalent to a small tunnel. A nearly 600-meter "rotten hole" also takes one to two years, and the 600-meter "rotten hole" is embedded in the depth of the tunnel, and its construction difficulty can be imagined. On the basis of dealing with three main faults and drawing lessons from the experience of several long tunnels in the past, the construction auxiliary tunnel scheme of "two inclines and one leveling" is adopted. The tunnel adopts advanced construction equipment such as rail gantry four-arm drilling trolley, vertical claw ballast loader, 14 cubic meter shuttle car transportation, formwork trolley and concrete pump lining, which creates conditions for rapid tunnel construction. According to the geological conditions, the main excavation method is normal section excavation, and the short step method is used in the weak surrounding rock area. The tunnel started on1October 1992, 1 1 and was completed on September 6th 1996. China Railway Tunnel Group (CTG) is the largest enterprise group in the field of tunnel and underground engineering in China. 1In May, 1978, the Ministry of Railways reported to the State Council for approval, and established 450 1 engineering headquarters in Luoyang, Henan. In June of the same year 10, the State Council approved the reorganization of 450 1 Engineering Headquarters into the Tunnel Engineering Bureau of the Ministry of Railways. 1September, 1999, the Tunnel Engineering Bureau was decoupled from the Ministry of Railways and renamed as. In May, 20001year, the Tunnel Engineering Bureau reformed the company system, and established China Railway Tunnel Group with China Railway Tunnel Group Co., Ltd. as the core enterprise, which integrates four functions of survey and design, construction, scientific research and development and machine maintenance, and is affiliated to China Railway Corporation. At present, the Group has 65,438+00 construction subsidiaries, 65,438+0 survey and design institutes, 65,438+0 scientific research institutes, 65,438+0 manufacturing enterprises, 6 regional headquarters in Beijing, Nanjing, Guangzhou, Xi, Chengdu and Wuhan, and 300 projects under construction, with construction teams all over the country. The main business scope and qualifications of the Group (the construction qualification only includes the first-class and above qualifications) include: the special grade of railway engineering construction general contracting; Highway engineering construction general contracting level 1; Municipal public works construction general contracting level 1; First-class general contracting of housing construction projects; General contracting of mechanical and electrical equipment installation project level 1; Tunnel engineering, bridge engineering, hydraulic tunnel engineering, highway subgrade engineering, mechanical and electrical equipment installation engineering, foundation and foundation engineering contracting first-class, urban rail transit engineering contracting first-class qualification (not graded); Comprehensive Grade B of highway and waterway engineering test and testing institutions; Grade A in municipal industry (bridge engineering, urban tunnel engineering, rail transit engineering and road engineering), Grade A in highway industry (extra-long tunnel), Grade B in highway industry (highway) and Grade A in railway industry (tunnel); Comprehensive Grade A of engineering investigation; Surveying and mapping qualification grade A; Grade A engineering consulting (railway tunnel, highway tunnel, urban rail transit, municipal public works (bridges, tunnels), geotechnical engineering, engineering investigation, hydrogeology); Engineering consulting class B (construction, municipal public works); Scientific research, design and technical services, etc. The group company and its main subsidiaries have successively passed the certifications of GB/T 1900 1 standard quality management system, GB/T2400 1 environmental management system and GB/T2800 1 occupational health and safety management system.
The whole group currently has1516 employees, including 7,437 professional technicians (50 1 person with senior title and13,865,438 with intermediate title) and more than 7,000 skilled workers, including 65,438 academicians of China Academy of Engineering. The registered capital of the group company is 1 1. 1 billion yuan, the total assets of the group are123 million yuan, the fixed assets are 2.4 billion yuan, and the owners' equity is193 million yuan. The Group owns 4,856 sets of machinery and equipment, with an original value of 2.42 billion yuan, a net value of 65,438+0.3/kloc-0.00 billion yuan and a total power of 496,5438+000 KW. TBM and 46 shield machines. Technical equipment rate 1.265 million yuan/person, power equipment rate 54. 1.8 kw/ person, 46 TBM and shield machines. It is the construction enterprise with the most complete types and the largest number of TBM in China, with an annual tunnel construction capacity of over 500km.
Over the past 30 years, the scale of enterprise operation and production has been expanding, and the market has been expanding from railway to railway and from domestic to overseas. Completed a large number of high-tech national key projects. Railway projects have participated in East Longhai, Hengguang, Daqin, Houyue, Baocheng, Jingjiu, Nankun, Huang Shuo, Xikang, Neikun, Liu Zhu, Meikan, Shen Yan, Xi 'nan Jing, Huai Yu, Gan Long, Qinghai-Tibet, Wu Lan, Yiwan, Dali, Luozhan, Shitai, Wu Guang, Hewu and Wu Kang. Construction of Lanzhou-Chongqing, Yumeng, Ku-Russia branch line, Shenyang Hub Northeast Ring Road, Northeast East Irrigation and other railway trunk lines and double lines. The famous long tunnels built or participated in are Dayaoshan Tunnel (14.3km), the longest single-track tunnel (20.5km), Wushaoling Tunnel (20.5km) and Xi 'an Ankang Qinling Extra-long Tunnel (/kloc-). Yuanliangshan Tunnel (1 1. 1 km) is the longest karst tunnel in China, and Yuntaishan Tunnel (8.2 km) is the longest gas tunnel in China. The famous long tunnels that have been built or participated in the construction of highway projects include: the Zhegu Mountain Tunnel on National Highway 3 17 (4,000m above sea level), the Erlangshan Tunnel on Sichuan-Tibet Highway (4.2km), the Huaying Mountain Tunnel on Guangzhou-Chongqing Expressway (4.7km) and the Zhong Shi Expressway in Chongqing. A large number of stations and sections have been built in Beijing, Shanghai, Tianjin, Nanjing, Guangzhou, Shenzhen, Shenyang, Xi, Hangzhou, Wuxi, Chongqing, Chengdu and Wuhan.
Since the restructuring of China Railway Tunnel Group in May, 20001,China Railway Tunnel Group has been aiming at the overall development goal of "leading in China and famous in the world", carrying forward the enterprise concept of "big industry, big school, big family and big stage", fully implementing Scientific Outlook on Development, advancing with the times, facing difficulties, seizing opportunities, improving capabilities, taking reform as the driving force, management as the basis and science and technology as the guide. Take innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, innovation as the driving force, and innovation as the driving force to promote scientific and modern management, so as to build a modern enterprise system that meets the requirements and adapts. The operation and production have reached a new level every year, and the competitiveness of enterprises has been significantly enhanced, realizing the sustained and rapid development of China Railway Tunnel Group in a highly competitive market environment.
Adhering to the technology research and development strategy, the Group is committed to the research, development and application of new technologies and new processes in the field of tunnel and underground engineering, and takes the lead in introducing, absorbing and comprehensively mastering NATM construction technology in China, especially in tunnel and underground engineering construction under complex and special geological conditions such as fault fracture zone, weak surrounding rock, expansive surrounding rock, high ground stress, coal-bearing gas layer, water inrush, karst, rock pile, quicksand loess and so on. In recent years, the application of large-scale advanced equipment construction technology has made a breakthrough, 5 1 shield engineering 195 km; Eight TBM projects have been completed, with a total length of 140 km. Up to now, 35 1 scientific research achievements of * * * have passed the evaluation, appraisal and acceptance of enterprises or provincial and ministerial science and technology departments, including 2 internationally advanced, 32 internationally advanced, 63 domestically advanced and 5 1 domestically advanced. Won 9 national science and technology progress awards (including the grand prize 1), 2 China Construction Science and Technology Awards of Zoomlion Cup, and 70 provincial and ministerial science and technology progress awards. 26 patents have been obtained, including 6 invention patents and 20 utility model patents. National construction method 17, Ministry construction method 43, enterprise construction method11. Adhering to the enterprise spirit of "precision, sincerity, excellence and innovation", the Group has carefully forged high-quality projects, and successively won 12 Luban Award for National Architectural Engineering, 12 Zhan Tianyou Award for National Civil Engineering, 3 National Gold Awards for Quality Engineering,1National Design Gold Award and 2 Silver Awards. The State Key Laboratory of Shield and Tunnel Technology of the Ministry of Science and Technology is located in our group company, and the china civil engineering society Tunnel and Underground Engineering Branch is located in our group. The Science and Technology Department of Henan Province has recognized our group company as a high-tech enterprise and enterprise technology center in Henan Province. The Group Company has successively won the honor of outstanding enterprises of China Railway Engineering Corporation, outstanding construction enterprises in Henan Province, outstanding ideological and political work enterprises in Henan Province, outstanding construction enterprises in China, the first batch of AAA credit enterprises in the construction industry in China, outstanding enterprises in China, honest units in China, construction enterprises with satisfactory users in China, home of national model workers, and award-winning enterprises in the national ankang cup competition, etc.