1 project overview
The newly-built Longxia Railway is a national key project, with a design speed of 200 kilometers per hour and passenger and freight lines. Xiangshan Tunnel, built by China Railway Tunnel Group, is the longest double-hole single-track tunnel in China and the most important control project. It starts from Sankeng Village, Caoxi Town, xinluo district, Longyan City, Fujian Province, passes through Xinci Village and Xiangshan Village of Zhongshi Town, and ends at Le Tu Village, Hexi Town, Nanjing County, Zhangzhou City. The left tunnel length is 15898m, the right tunnel length is 159 17m, and the maximum buried depth is 830m. There are five inclined shafts in the tunnel. 1, No.5 inclined shaft adopts trackless transportation, and No.2, No.3 and No.4 inclined shaft adopts rail transportation. The inclined lengths of inclined shafts 1, 2, 3, 4 and 5 are 907. 15m, 508. 17m and 905.65 respectively.
Xiangshan tunnel is constructed in six work areas, crossing the entrance and exit and five inclined shafts, with a total of 24 excavation faces. During the peak construction period, there will be more than 100 parallel working faces, more than 5,000 construction workers and more than 1320 sets of construction equipment. The auxiliary tunnel and large-scale mechanized supporting construction technology are adopted to realize short-distance rapid construction of long tunnels. The contract period of Xiangshan Tunnel is from February 30, 2006 to October 29, 2009/kloc-0, with a total of 1034 calendar days ***34 months, in which the right line must meet the bridge-laying conditions within 28 months. Xiangshan tunnel (inclined shaft) passes through mined-out areas, reservoirs and rivers, and passes through coal seams, karst areas, at least 10 fault zone, groundwater development zone, soft rock stratum, high temperature zone, high stress zone, abnormal rock radioactivity zone and other adverse geology. The geology is extremely complicated, the technology content is high, the construction is difficult, and the construction period is extremely urgent. Water outburst prevention, mud gushing, collapse, large deformation of soft rock, gas, rockburst, radiation and the construction organization and management of multiple working faces are the outstanding difficulties of this project.
No.3 inclined shaft is located on the right side of the line, Xiangshan Village, Moderate Town. The included angle with the long-distance direction of the line is 17, and the intersection mileage between the center line of the inclined shaft and the left line is YDK28+230. The minimum excavation section (width and height) of No.3 inclined shaft is 706cm-628cm. The connection mode of inclined shaft and main tunnel is orthogonal compound, and four-lane rail transportation mode is adopted. It has the characteristics of long oblique distance and large slope, and is the key control project of Xia Long Railway, which restricts the construction period of the whole line. Its safety, high quality and timely completion are of great significance.
2 selection principle of inclined shaft hoisting equipment
The principle of determining the lifting equipment of inclined track shaft is mainly determined by the construction progress and lifting capacity. In order to ensure the smooth progress of Xia Long railway construction project and complete the construction task on schedule, the lifting capacity of track inclined shaft is mainly determined by the following conditions:
1) hoisting speed: The hoisting equipment of inclined shaft is affected by the laying quality of inclined shaft track. Considering the driving safety comprehensively, the maximum rope speed of steel wire rope should be about 5.0m/s..
2) Lifting capacity: The lifting capacity of lifting equipment is determined by the power of the engine. When the maximum rope speed is fixed, the greater the engine power, the greater the lifting capacity. In terms of equipment, the mechanical equipment capacity is greater than the progress index capacity, and there is sufficient equipment reserve.
3) Capacity of mine car: The greater the ballast loading capacity of mine car, the greater the lifting force required and the higher the requirements for lifting system. According to different working procedures, the assembly line is organized according to specialization, and the main operation lines such as digging and loading, transportation, bolting and shotcreting, lining and auxiliary operation are assembled with large equipment with good performance, high efficiency and good machine condition, so as to realize the organic cooperation of all mechanized operation lines and realize the stable and high yield of tunnel construction with improved mechanization. Electro-hydraulic is the first choice for equipment selection, and trackless mechanization supporting technology is adopted for mechanical equipment, so that the whole line can form rapid construction capacity. Mechanical equipment should be equipped to adapt to the characteristics of extra-long tunnels. According to the construction characteristics of No.3 inclined shaft of Xiangshan Tunnel in Xia Long Railway, when using inclined shaft lifting equipment, the safety hazards such as anti-skid measures and water inrush and mud outburst should be considered emphatically.
3 major equipment configuration
In the construction of inclined shaft, PC60 excavator is used to ballast, and 2.5m diameter double drum winch is used to lift 10m3 side dump tramcar, which undertakes the tasks of ballast and transportation of building materials. When the inclined shaft is excavated to the main tunnel, during the construction of the main tunnel, the 10m3 side dump car will be lifted by a 3.0m diameter double drum winch to undertake the tasks of slag discharge and material transportation in the initial support construction; 2.5m diameter double drum winch lifts 4m3 track tank car to undertake the task of lining concrete and transporting construction personnel. The wellhead ballasting adopts curved track automatic ballasting, and adopts an open ballasting bin which can store a certain amount of ballasting materials, thus avoiding the coordination problem of one-to-one ballasting between dump trucks and mine workshops, and making the wellhead ballasting unaffected. A ZLC50C loader is placed in the ballast bin, and the ballast is loaded into a dump truck and transported to the slag dump. A funnel is set at the bottom of the well, and the dump truck directly unloads the hole slag into the mine car by using the height difference. When dump trucks and harvesters can't absolutely correspond, it can be considered to directly unload the ballast near the funnel, and the loader directly feeds the harvesters to lift them out of the hole.
In order to facilitate the initial supporting materials and other materials to get on the train quickly, a small portal crane with a weight of 5t is set on the track. After the materials are transported to the track by car, they are directly hoisted to the car by a door crane and transported to the bottom of the well. There are also door cranes at the bottom of the well, and then they are hoisted from the car to the car and transported to the working surface. In order to facilitate the rapid transportation of concrete to the tank car (mine car), the mixing station is directly installed next to the track to avoid concrete being transported. In order to realize continuous mixing of the mixer, a silo with a storage capacity of about 4m3 is set below the mixer for mixing and spraying concrete. The sprayed slurry is temporarily stored in the silo after being discharged from the mixer, and a belt conveyor is set below the silo to transport the sprayed slurry to the mine car. Three-dimensional transfer is adopted at the bottom of the well, and the shotcrete car falls into the underground car by the height difference, and then it is transported to the working face by the underground car tracklessly. After the lining concrete is mixed, it can be directly sent to the track tank car (King Kong car) through the chute. Considering that the mixer can continuously stir when the king kong car is driving, two king kong cars are hung in one lane, so that when a king kong car is driving and unloading, there is always a car loading at the wellhead. The bottom hole king kong car uses the height difference to directly unload the concrete into the concrete transporter, and the concrete transporter transports it to the working face. In order to realize the rapid transfer of bottom-hole materials and ballast, a relatively simple method is adopted according to the bottom-hole topographic conditions and the height difference. The unloading location of various materials and the receiving channel of the car should be considered in the transshipment location.
4 Inspection and calculation of lifting equipment
4. 1 Selection of lifting container
According to the design section of inclined shaft and bottom hole equipment, large tramcars are selected for lifting. Using 10m3 large side dump car, double hook hoisting.
1) lifting calculation.
Calculation of daily promotion of Vmax:
Vmax= monthly maximum excavation volume of main tunnel-unconsolidation coefficient ÷ monthly working days = 127 1m3.
2) hoisting time t:
Choose a hoist with a rope speed of 4.6m/s. Considering the influence of acceleration and deceleration before and after lifting, stopping and unloading, the lifting cycle time is calculated as 290s, and the size of lifting container is calculated as follows:
Where K 1 is the filling coefficient of the container, taking 0.9; K2 is the lifting unevenness coefficient, which is1.2; Vmax is the maximum lifting capacity, m3, taking1271; T is the lifting time, s, taking 290; T is the daily promotion hour, taking 16.
After calculation: V-hook =8.53m3, choose 10m3 car, and 1 car every time.
4.2 Selection of cranes
1) The maximum static tension f is the largest.
f max = n(q 1+Q2)(sinα+f 1 cosα)+pkl(sinα+f2cosα)。 Where n is the number of cars to be lifted at one time; Q 1 is the dead weight of the lifting container and the connecting device, which is 5870kgQ2, and the effective load of the lifting container is15000 kg; α is inclined angle of inclined shaft, 22.86; F 1 is the resistance coefficient of the lifting container, which is 0.01; F2 is the resistance coefficient of wire rope movement, taking 0.25; Pk is the weight per unit length of hoisting wire rope, which is temporarily calculated? 37 steel wire rope, 3.446 kg/m; L is the lifting length of steel wire rope, which is 900m·m m. After calculation:
f max = 1-(5870+ 15000)-(sin 22.86+0.0 1-cos 22.86)+3.446-900-(sin 22.86+0.25-cos 22.86。
2) Maximum static tension difference F difference.
F difference = fmax-NQ1(sinα-f1cosα) = 7329-1-5870-(sin22.86-0.01-cos22.86) = 7992.7kg.
3) Selection of hoist.
Xkt 2-3-1.5b-1.5 hoist with 6 10kW motor, maximum static tension 13000kg, maximum static tension difference of 8000kg, which can completely meet the hoisting calculation.
4.3 Selection of Wire Rope
According to "Coal Mine Safety Regulations", the safety factor of wire rope is 7.5, and the total breaking force of wire rope is required to be 7.5-F max = 76642.5kg. Choice? 37 steel wire rope, tensile strength 1700MPa, total breaking tension of steel wire rope 82500kg.
4.4 Selection of diameter d of basin gear
To use the traveling crown block, the rope with a diameter of 40~60 is required, and the crown block with a diameter of 2500mm can completely meet the requirements. Inclined shaft hoisting system adopts double hook slag discharge and single hook feeding, so each wellhead is equipped with four 8m3 tramcars; 3m3 concrete truck transport concrete materials, 4m3 car transport other materials, personnel arrangement from top to bottom to use 22 passenger cars; The main tunnel section adopts trackless transportation. Considering that there may be two operations at the same time, eight dump trucks and three loaders are arranged at the bottom of the well. Considering the characteristics of tight construction period, heavy pressure and heavy tasks, the equipment configuration is appropriately increased and the main construction equipment is fully reserved.
5 Overall evaluation of current equipment selection
The equipment configuration of track inclined shaft fully considers the influence of inclined shaft running speed. Combined with the requirements of construction and production, high-power and large-capacity lifting equipment is adopted. The maximum monthly footage is 150m, which can basically meet the overall requirements of the construction team for the construction period.
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