Organization design for safety and quality management of railway engineering
2.1 Design Situation 2.1.1 Project Scale This bid section XX6 is located between XX County and XX City, with the starting and ending mileage of DK351+500 ～ DK402+525 (comprehensive civil works), and the main line is 51.025km long. The starting and ending mileage of erection is DK244+568 ～ DK418+200, the main track laying is 344.8km, and 1343 beams are erected. XX tunnel is located in the denuded hilly area, starting from DK365+889 to DK368+365, with a total length of 2476m. Our department undertakes the task of 1585m at the exit section of XX tunnel. The maximum buried depth of the tunnel is 178.7m, which is a mountain deep buried tunnel. The slope from the tunnel entrance to the tunnel exit is 4.5 ‰. XX medium bridge: the line is located on a straight line, with a line spacing of 4.0m, a bridge length of 84m, and two piers and two abutments. Double track T-type abutment is adopted for abutment, double track round end solid abutment is adopted for pier, and all fixed bearings are set at Tanghaifang of each simply supported beam. The XX tunnel mileage is DK368+614~DK371+300, with a total length of 2686m (including 812m for Grade II surrounding rock, 1018m for Grade III surrounding rock, 698m for Grade IV surrounding rock, 146m for Grade V surrounding rock, and 31.6% for Grade IV and V surrounding rock). It is a single hole double track tunnel, with the maximum burial depth of 224.8m. The section from tunnel entrance to DK368+877.6 is located on the right deviation curve with a radius of 3995.89m, and the curve length is 299.68m. The rest of the tunnel is located on a straight line. The slope from the tunnel entrance to the tunnel exit is 12.05 ‰. Our department undertakes the task of 1343m at the exit section of XX tunnel. 2.1.1.1 Main quantities Main quantities Table No. Project name Unit quantity Subgrade 1 Excavation cubic meter 33374.4 2 Fill cubic meter 709 Two bridges (XX medium bridge) Lengthened meter Nr. 84.03 1 Tunnel Lengthened meter Nr. 2928 2 1 XX Tunnel Lengthened meter 1585 ① Excavated cubic meter 145594.2 ② Lining masonry 25435.28 ③ Support Lengthened meter 1585 2 XX Tunnel Lengthened meter 1343/1 ① Excavated cubic meter 132481.18 ② Lining masonry 45615.45 ③ Support Lengthened meter 1343 2.1.2 Technical standard XX line is located in northern and eastern Hebei Province of China. The line starts from XX Village, XX City, and extends eastward to connect XX West Line and XX Line; Conditions for connection with Line XX and Line XX are reserved. The total length of the line is 528.5km, with 16 stations. The line is classified as Grade I, and the number of main lines is double track. Electrified heavy haul railway is newly built, and the target design speed is 120km/h. 2.1.3 Project characteristics (1) The construction access road is close to the river, so it is difficult to build and widen, and it is inconvenient to access materials. The construction and living sites of the Management Department involve a large number of trees, demolition of residential buildings, relocation of factories and mines, etc., and the villagers have a great interference. (2) The amount of tunnel spoil in this project is large, the spoil ground is narrow, and land acquisition and demolition are difficult. The total amount of spoil is about 311000 m3 (solid), which is treated as spoil. It is necessary to do a good job of spoil protection and drainage supporting works. The spoil is combined with the local farmland water conservancy construction. After the construction, the spoil yard is leveled and protected, and grass seeds are sown for greening. (3) The project has high quality requirements, tight construction period requirements and difficult construction organization. The XX tunnel in this section is 1585m long, and the total construction period is only 12 months. The construction period is tight. The average monthly progress index of Grade V surrounding rock is 50 meters, and the average monthly progress index of Grade IV surrounding rock is 80 meters; The average monthly progress index of Class III surrounding rock is 150m, and the average monthly progress index of Class II surrounding rock is 180m. (4) Winter construction is required for this project. The management department is located in the warm temperate zone, sub humid continental monsoon climate zone, dry and windy in spring; The precipitation is concentrated, mostly distributed in July and August, and the evaporation is greater than the precipitation. The evaporation is strong and lasts for a long time. It is hot in summer, cool in autumn, and cold in winter. The average temperature of the coldest months over the years is - 8.5 ℃, the minimum temperature of the period can reach - 25 ℃, and the maximum freezing depth of the soil is 1.26m. The temperature difference between day and night is large. It brings great difficulties to the winter construction. The office, domestic cold protection, production and domestic water, concrete construction, mechanical cold protection, etc. need to analyze and study the countermeasures, and formulate corresponding construction measures according to the specific situation. 2.1.4 The key and difficult tunnels of the project have large sections, long single heading distance, large interference between processes, tight construction period, winter construction, etc. 2.1.5 Tunnel entry construction at project risk points, excavation of Class IV and V surrounding rock, blasting operation, tunnel transportation, collapse and tunnel through construction. 2.1.6 Geological exploration, monitoring measurement and construction measurement of quality monitoring points, initial support (anchor bolt length and insertion, steel arch erection, steel bar binding), waterproof system, lining thickness. 2.2 Construction conditions 2.2.1 Topography and geomorphology The stratum within the pipeline section is Indosinian quarterly () granite. Granite: grayish white mixed with flesh red, medium coarse grain structure, massive structure, relatively developed joint fissures, the main joint occurrence is and, and the spacing is 40~80cm and 30~100cm respectively. See "Table 3-1 Classification of Geotechnical Construction Works" for the classification of geotechnical construction works.
