The Research On Dust Prevention And Control In The Tunnel Construction With Drilling And Blasting Method

The dust pollution, which is produced during the tunnel construction process with drilling and blasting method, such as the drilling, blasting, shipment of tunnel muck, shotcrete, on-site steel bar welding, waterproof layer welding and lining concrete, can do great harm to workers' health. It has been reported that the long term inhalation of dusts containing free silica is prone to induce a systemic disease, namely pneumoconiosis, mainly with diffuse fibrous lesions of lung. Therefore, it is very urgent to carry out research on dust prevention and control so as to improve the operating environment and minimize the occurrence of occupational diseases. The research on dust prevention and control in the tunnel construction with drilling and blasting method shows the results as follows:In order to put forward prevention measures of the tunnel construction, dust production mechanism was firstly studied to analyze its source, capacity, nature and so on. According to the analysis of the primary procedure and techniques of the construction, together with practice test and comparison, the dust source and key procedure and techniques of the construction, as well as its influence scope, are identified.The one-sided understanding of successful dust control is always considered to discharge dust to the outside of tunnel. However, large quantities of dust mainly generated at the most end of tunnel can pollute the whole tunnel during the dust exhausting, thus those workers involved in the construction and management of the tunnel are all subjected to hazards. In this study, dust suppression and removal are treated as the key points in the dust prevention and control of the tunnel construction to minimize the quantity of dust in the working surface by the application of advanced techniques and equipments. In addition, tunnel ventilation is achieved mainly by the oxygen supply and cooling. In a word, it will greatly reduce the ventilation volume and costs and improve the dust pollution in tunnels by adopting comprehensive measurements for reduction.After the in situ tests of the tunnel construction and analysis of the dust control methods, comprehensive control measures are put forward, which are also verified by comparison and cases that the construction process of water blasting, wet drilling, wet shotcrete and the technology of automatic water screen dedustering and electrostatic precipitation can not only greatly reduce the concentration of dust and its harmfulness, but will also improve the construction quality and security.In addition, the dust prevention and control applied to the construction management is also a powerful way to strengthen normalized management of the construction process and improve the overall management of its environment. Moreover, it also provides a reference for making a policy related to the dust prevention and control in the tunnel construction.