Railway Tunnel Risk And Disease Analysis And Preventive Measures

Along with the state's investment in railway construction projects,the mileage of our railways has increased year by year.The railway mileage has increased the proportion in the opening of railway lines.By the end of 2016,a total of 13205 railway tunnels have been put into operation in the country,with a cumulative length of 13583 km,which is the largest railway tunnel in the world.At present,a total of 2078 railway tunnels are built,with a cumulative length of 6733 km.The total length of the tunnel will be 3586 in the near future,with a cumulative length of 8033 km.The distribution of the super long tunnel is: a railway tunnel with more than 10 km operation has been accumulated,and the total length is 136.The total length of the tunnel is 1986.4km.Secondly,the total number of 20 railway tunnels running over 20 km has been accumulated437.4km.With the railway transport demand and operating mileage continues to expand,the number of Railway Tunnel Risk and disease is also increasing,the event risk of railway tunnel is often accompanied by casualties,economic losses and property heavy traffic interruption and other adverse consequences,based on the analysis of typical main risks and diseases of railway tunnel case analysis and preventive measures at the same time,combined with the existing technical scheme,and the method of obtaining process description successful focus on remediation and disease risk in detail,for the follow-up control of the disaster has a certain guiding role,through the case analysis and practical analysis,the existing domestic construction operation of the tunnel diseases and the analysis of its there are several reasons:First,the design causes such as the early construction of the congenitally deficient,Longhai,Baocheng,Cheng Kun line,due to lack of experience,blindly copy foreign,in line selection for narrow tunnel length and hole processing due to improper slope instability;ignored when the train is running on the tunnel bottom damage,arch or bedding design due to the lack of strength of crack damage of tunnel deformation;drain depth due to insufficient drainage tunnel bottom caused by uneven bed mud.Second,the quality of construction is low.Such as construction units according to the design and specification for waterproof facilities caused by structure leakage;construction for tunnel surrounding rock stability and ignore the quality of inverted arch or bottom,especially the bottom cleaning work is not attached to the quality and effect of bedding;ineffective supervision,hidden engineering and concrete engineering can not according to the standard construction due to structural defects.Third,technical problems of high difficulty under special geological conditions to solve the improper for days after the operation lay hidden tunnel.Fourth,with the prolongation of service life,the lining material deteriorated.Fifth,the frost damage in the high and cold regions causes the cracking of the lining structure.Sixth,in the coal seam area,due to the formation of coal in the empty area,the stress redistribution of the tunnel surrounding rock causes the instability of the surrounding rock,resulting in structural fracture damage.By summing up,the classification of Tunnel Risk and disease is as follows:The type of railway tunnel risk are: landslide,mud water inrush and other,such as fire,explosion,collapse and reinforced support.Among them,the highest frequency of occurrence of collapse risk,accounting for the total amount of accidents,the greatest harm;followed by water and mud bursting accident.Tunnel diseases mainly include: arch cracking off block,struck the empty ring(open hole,insufficient thickness),repair shed,rebar inadequate or incorrect location,infiltration or Water Leakage gushing water,less dense concrete and circumferential waterstop concrete cutting and tunnel foundation settlement anomaly.At present,the quality of the tunnel engineering is more serious,and the risk is very high,and the safety risk after the opening is high.To sum up the characteristics of the four: one is hidden,as everyone knows,in the railway tunnel is completed,we can only see the apparent external lining,the lining thickness behind the existence of void,whether meet the design requirements can be found directly;the two is sudden,railway tunnel safety risk accidents and diseases often exist uncertainty,such as the following in the rock fall,collapse,water bursting mud and other phenomena occur in advance can not be timely and accurate judgment,when the accident happened often causing traffic interruption or personnel casualty;three is the complexity of China vast geographical area,the geological conditions and the geographical environment is complex and changeable,in the exploration according to the current specification and design conditions,there are lots of risk identification is not in place,which leads to frequent railway accident Students;four is repeated,as described in the text of the tunnel Water Leakage phenomenon,has a large proportion in China's railway has been opened,such problems are generally difficult to be completely radical.In the long term railway tunnel disease regulation work,various departments of the Ministry of public works have learned a set of effective methods and standards for disease management through years of exploration.However,due to lack of funds and driving needs,the way of disease control is still at a standstill,and it only meets the needs of temporary driving and cannot achieve the purpose of radical cure.This is mainly due to: first,the mechanism of the disease is unclear;second,the disease harm degree and effects of vehicle speed evaluation structure allowed;third,by restricting the capital and technology and other objective conditions,process and material is relatively backward;the regulation method,and fourth construction organization is inadequate.Therefore,the long-term development of domestic railway operation must be radically eradicating the existing disease tunnels,so as to make the disease management develop from the blindness and local assault to the systematization and standardization,and form a scientific and reasonable construction system.On the basis of a large number of case analysis and calculation,the following conclusions are drawn.1.tunnel foundation settlement deformation abnormal through the strengthening of the tunnel geological conditions and geological structure fully analysis,combined with effective daily observation data,through the1.Abnormal deformation by strengthening the analysis of tunnel geological conditions and geological tectonic subsidence of 1.tunnel foundation,combined with the daily observation data effectively,the solution calculated V rock under the arch ofdisplacement and stress are greater than VI in surrounding rock,and the surrounding rock under the inverted arch construction of bored pile in grouting and after the initial supporting arch at the axial force is still large,so for the surrounding rock under the inverted arch reinforcement design proposal of bored pile in grouting foundation;and for the surrounding rock under the arch arch grouting reinforcement,uplift in the back if you can stay in the 1mm,can no longer play.Bored pile.2.arch cracking block,struck the empty ring(open hole,insufficient thickness),tunnel disease repair off and rebar are inadequate or incorrect location,infiltration or Water Leakage gushing water,less dense concrete,concrete cutting ring to strip tunnel operation period,in the construction period,the construction of advanced technology and the effective management measures,can greatly avoid the occurrence of disease.3.the risk of tunnel collapse in the construction of water mud inrush occurs in the process,strengthen the work of geological prediction by using geophysical techniques,and surrounding rock monitoring combined with the actual measured data,the risk of early pre judgment and disposal,can greatly reduce the occurrence of the accident.4.Tunnel Risk and disease occurrence and construction managers sense of responsibility and professional level has a greater relationship,which requires us in the subsequent construction process to strengthen personnel management and control efforts.