1. Mechanical equipment
Drilling, blasting and shipping are the main processes in roadway construction, and the rational selection and use of drilling and shipping equipment will directly determine the tunneling speed.
(1) drilling holes. The current roadway tunneling is still commonly used in gas-bore rock drills (such as the Model 7655, YT-28, YTP26, etc.). Because the output power of the gas-leg rock drill is small, the drilling speed is low, and the depth of the drill hole is shallow, to improve the working surface. The drilling speed is much more than the machine work, but the work efficiency of the tunneling still cannot be improved. Some of China's engineering projects have been constructed with single-arm, double-arm or three-arm rock drilling rigs. However, in terms of the use and renewal degree of rock drilling equipment in China, most of them still remain at the first and second generation levels, namely the air legs. Rock drill or semi-hydraulic rock drilling rig level. In foreign countries, shield tunneling machines or TBM tunneling machines have been basically used in large-section roadways. Rock drilling rigs are used in small sections, so that the drilling is replaced by brazing, positioning, drilling and returning. In addition, in the 1960s, the first full-section roadheader with a diameter of 3.1m in the United States was successfully tested (the monthly footage in shale reached 2087.6m), which brought a new revolution to tunneling. After nearly 50 years of continuous research, from a technical point of view, it has been able to drill in any rock. Because the full-face tunneling machine has high tunneling speed, low cost, high work efficiency, good tunneling quality and safety and reliability, it is bound to replace other rock drilling equipment.
(2) Shipment. The rock loading process accounts for 30-50% of the total cycle time in the roadway excavation. At present, the mechanization operation has been basically realized in China. From the 1950s to the present, the loading machinery in China's engineering construction has undergone four stages of renewal. The general trend in loading rock is to provide intermittent equipment for low-efficiency loading equipment , and to continuously export to high efficiency. Supporting the development of equipment, that is, the crab claw or claw loader with continuous operation is matched with the belt transfer machine and the mine car, or the trackless scraper used or the large tonnage dump truck is equipped with The efficiency of tunneling is increased by 1 to 2 times, and the timing of calibration is shortened by 75 to 80%.
2, production technology
According to the current construction level of roadway excavation in China, the drilling and blasting method is still widely used, and the support method is basically anchor spray support. The method is superior to the traditional shed support and masonry support method in terms of construction speed, safety quality, labor intensity and production cost. However, there are still some problems in the construction. For example, due to the poor formation of the roadway, the quality of the net and the spray is poor, and the installation quality of the bolt is not good. For the poor surrounding rock, there will be safety hazards, and the progress of the roadway will be restricted.
(1) Improve light blasting technology and strengthen roadway formation. Current roadway blasting adopts smooth blasting, and most of them are shallow hole blasting. In order to improve the footage, it can be started from increasing hole depth and aperture, and after many years of practice, medium and deep holes ( 5m) blasting is also possible. At the same time, in order to strengthen the roadway molding, the number of expansion holes reduced by increasing the aperture can be transferred to the periphery, that is, the number of peripheral eyes is increased to ensure the light explosion effect. Moreover, increasing the hole depth and the number of blastholes can improve the pure drilling time of the trolley and fully utilize the utilization of high-efficiency equipment.
(2) Reasonable selection of anchors to improve the installation quality of the anchors, the most important is whether the selection is correct and the installation specifications are not. Different surrounding rock should be selected with reasonable anchors, such as mortar anchors, resin anchors, hollow grouting anchors and prestressed anchor cables, and piercing stress anchor cables. The anchor installation angle, whether the anchor pad is close to the rock face and whether the grouting is full will directly affect the anchoring quality.
(3) selection of qualified materials to ensure a major increase flexural strength and toughness sprayed concrete mass sprayed metal mesh net, but the installation must be close to the rock face. Selecting the qualified spray slurry to produce the crucible and selecting the wet spray process can not only improve the shotcreting effect, reduce the rebound rate, but also improve the working environment.
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