1、 西南交通大学本科毕业设计（论文） 第 14 页 Urban Underground Railroad arch tunnel Construction Technology Group Abstract Project in Guangzhou Metro Line, right-arch construction method of tunnels to explore. Subway Construction in Guangzhou for the first time put forward a double-arch tunnel to single-hole tunnel con
2、struction technology, and a single type of wall and split in the wall structure, comparison and selection of Technology solutions were obtained to meet the structural safety, construction safety and Economic benefits of better Technology solutions for the future design and construction of similar pr
3、ojects to provide reference and reference. Keywords: double-arch tunnel group; a single type of wall; construction Technology; split in the wall. As the circuit design requirements subway tunnel, the tunnel structure produces a variety of forms, ranging from cross-section from double-arch and the th
4、ree-arch tunnel composed of double-arch tunnel section is commonly used in the connection lines and crossing lines. In this paper, engineering examples, according to tunnel in which geological conditions, duration requirements, raised through the comparison and selection can achieve rapid constructi
5、on and the purpose of construction cost savings of the best construction programs. 1 Project OverviewGuangzhou Metro Line Road station turn-back line of sports for sports Road station after the return line, structure complex, DK3 016.047 037.157 varying cross-section set the double-arch structure, t
6、hree-arch structure of tunnels. Ranging from cross-arch tunnel excavation span 20.1m, excavation height of 10.076m, cross-vector ratio of 1:0.5, after lining a hole span 5.2m, large holes, after lining span 11.4m, the wall thickness of 1.6 m. Three double-arch tunnel excavation span 19.9m, excavatio
7、n height of 7.885m, cross-vector ratio of 1:0.1. -Arch tunnel section of rock from top to bottom are: artificial fill soil, red - alluvial sand, alluvial - alluvial soil, river and lake facies soil, plastic-like residual soil, hard plastic - a hard-like residual soil, all weathered rock, strong weat
8、hering rock, the weathered layer and the breeze layer. Tunnel through the rock strata are more homogeneous, the intensity high, carrying ability, good stability. Thickness of the tunnel vault covering 15.5 18m, of which grade Wai rock vault thickness 5.6 7.6m. Double-arch tunnel segment groundwater
9、table is 2.28 4.1m, mainly Quaternary pore water and fissure water. Section 2 dual-arch construction scheme comparisonAs the double-arch tunnel segment structure more complex, the tunnel cross-section changes in large, complicated construction process, construction was very difficult, the constructi
10、on cycle is long, so I chose a good quality and efficient completion of the construction program segment arch tunnel construction is particularly important. Selection of a construction program, the main consideration the following aspects: (1) construction safety and structural safety; (2) construct
11、ion difficulties; (3) the construction cycle; (4) cost-effectiveness. Based on these four principles, through the construction of research and demonstration program to select the following two programs to compare the selection of the construction.2.1 a single type of wall construction plan The progr
12、ams main construction steps and measures are as follows: (1) The right line of double-arch tunnel hole within the return line side of temporary construction access, dual-arch and the three-arch in the wall construction, is completed in a timely support for the wall, the construction to prevent bias.
13、 (2) construction of the wall lining is completed, according to first small then big, closed into a ring principle, the right line with the step method of construction, with CRD engineering method returned a four-lane span tunnel construction. (3) When the return line side of the construction to the
14、 three-arch tunnel in the wall, then in accordance with the right line of the wall construction method and the three-arch-arch in the wall construction, during which the right line to stop excavation until the completion of construction of the wall. (4) The return line side of the wall construction
15、is completed, the right line to continue to move forward the construction. The construction method for the domestic double-arch tunnel of conventional construction method, Guangzhou Metro, Nanjing and Beijing Metro subway both applications, and can secure successful completion of the construction of
16、 tunnels. However, examples of past engineering and construction Technology research can be found, the program has weaknesses and shortcomings. (1) The program used in this project, in a short span of 21.11m of double-arch tunnel, the tunnels opening between the supporting and secondary lining will
17、be converted four times, the conversion too frequently. (2) wall and side holes covered by waterproof layer of tunnel lining construction, steel engineering, formwork, concrete pouring required multiple conversions, the construction period up to 2 months. (3) The lining is completed, the wall of ant
18、i-bias materials, equipment, support and input, resulting in higher construction costs, Economic efficiency will drop. 2.2 The split in the wall construction plan The programs main construction steps and measures are as follows: (1) ranging from cross-double-arch tunnel into two single-hole, change
19、the formula for the separation wall, the first line of one-way right-forward construction of the tunnel. (2) three arch tunnel in the wall to make the first non-Shi lining, according to single-line working condition through. (3) the right line of large-section double-arch tunnel wall construction me
20、thod adopted in accordance with CRD. (4) The return line is in accordance with the right line of the opposite side of the construction sequence of construction. Adoption of this program is in fact a one-way in accordance with the construction of two methods, compared with the previous one, after the
21、 program has the following advantages:(1) reduction of the construction process to speed up the convergence process conversion. (2) reduce the construction difficulty, shortening the construction cycle. (3) reduce the construction costs and improve Economic efficiency. (4) change a single type of wa
22、ll to separate the wall, completely solved the structure of double-arch tunnel waterproofing defects. (5) The three-arch tunnel in the latter pArt of the construction hole, equivalent to large-span rock tunnels reserved for the core is conducive to both sides of the double-arch tunnel construction s
23、afety (Table 1). Section 3 three-arch construction plan Right-line direct access to three double-arch tunnel, the Support parameters to the original designs for grating erection of the whole ring, according to design the whole ring of shotcrete, and enhance the bolt at the wall vault settings (retur
24、n right side Tong Line Construction method), wall construction in the tunnel when you need to get rid of Office, located at a vertical grill joints strengthened beam. Strict control of excavation footage of each cycle, grid spacing of 0.6m / Pin. Weak in the wall excavation using millisecond blastin
25、g program (conditional maximize the use of static blasting programs), minimize the wall rock and the lining of the tunnel has been disturbed, to ensure construction safety. The completion of excavation in the wall immediately after the secondary lining. After the completion of construction of the wa
26、ll in wall voids of the backfilling, plus jack supports. The side of the construction is completed, carry out the other side of the wall construction. When both sides of the wall construction is complete, in a timely manner on both sides of a single-hole tunnel secondary lining, and then proceed to
27、three-arch tunnel excavation and lining of the middle of rock. Construction, special attention should be three arch tunnel in the wall at the settlement and convergence deformation, such as the unusual phenomenon, an immediate reinforcement.4 construction of the force structure of Behavior Analysis
28、Across the range of the double-arched wall canceled, changed to separate the wall, in the domestic urban underground railway engineering has not yet been a similar engineering design and construction experience, there is no such tunnel structure design, and therefore the structure is safe, as well a
29、s the course of construction conversion process of construction is safe, the program will be the focus of the study. Application of ANSYS finite element software for common procedures ranging from cross-arch tunnel numerical simulation, using stratigraphic - structural model of the structure of the
30、tunnel by the force and deformation analysis (Figure 1, Figure 2, Figure 3). The scope of the horizontal direction taken by force along the direction of the tunnel cross-section to cross-hole 3 times the limit, taking the top of the vertical direction to the surface, the bottom-hole span to 3 times
31、the limit, unit model uses the DP formation of elastic-plastic material entity, the tunnel Lining with elastic beam element simulation, beam elements and solid elements used to connect coupling equation. Through the analysis of data in Table 2 we can see that during the construction of large tunnels
32、 in a greater impact on small tunnel, if a small section of the tunnel with the necessary strengthening of measures and control the removal of temporary support to the longitudinal spacing, the program is useful and feasible to The.5 Construction of key technologies and corresponding measures Arch t
33、unnel construction segment is required on a strict construction organization and strong technical assurance measures carried out under the good job in organizing the construction of steps to prepare the construction of a variety of technical preventive measures are key to success.5.1 pairs of pull a
34、nchor and strengthen the bolt Abolition of a single type of wall, the excavation is complete in the wall thickness of 0.8m, pull anchor and strengthen the right bolt set is very necessary. 22 steel bolt used on the pull bolt drug volume, pitch, 0.6m 0.5m, the length of the wall thickness according t
35、o the 0.8 2.0m. Strengthen the bolt in the wall located at the invert and side walls at both sides, using 3.0m of 25 hollow grouting anchor, spacing 0.6m 0.8m. 5.2 in the body wall, grouting rock block folders In the wall of rock thinnest Department to 0.15m, after repeated blasting excavation proce
36、ss, the impact of the rock wall around the loose, their bearing capacity affected. Therefore, we must separate the wall in the vault, wall, invert Department for loose rock for grouting. 42 embedded steel, cement slurry to take - water glass pairs of liquid slurry, the parameter of 1:1 cement and 30
37、 45Be sodium silicate solution, grouting pressure of 0.2 1.0MPa. In both excavation grouting in the wall were carried out, after the completion of the final excavation carried out in saturated sandwich wall grouting. 5.3 millisecond blasting technology microseisms Tunnel excavation construction meth
38、od used in all drilling and blasting. Because the lot is located in downtown Guangzhou, the ground-intensive buildings, and the Tunnel 0 spacing excavation, blasting must be set aside in accordance with glossy layer of smooth microseismic millisecond blasting program construction blasting vibration
39、control will be allowed within the . For the double-arch tunnel in which strata of , grade rock blasting to take measures as follows: (1) The blasting equipment, using low-speed emulsion explosive shock. (2) strict control of footage per cycle (0.6 0.8m), around the borehole spacing of 0.4m, reduce
40、the loading dose to control the smooth blasting effect (Figure 4). (3) The use of multiple detonators per blast detonation, using non-electric millisecond detonator initiation network asymmetric micro-vibration technology. (4), excavation and construction of the wall at the second to take first rese
41、rve 1m smooth layer, Cutting away from the eyes arranged in the side of the wall on the second floor reserved for smooth blasting around the eyes more than surface layout of the empty eyes, a small charge. Put an end to ultra-digging, digging, when partially due to artificial air pick excavation. Th
42、rough the above effective measures, in the wall during the construction of the second blast, right in the thick wall of 0.15m basic did not cause damage to the smooth passage of the double-arch tunnel 0 from the excavation.5.4 Auxiliary scissors to strengthen supporting By ANSYS simulation analysis,
43、 in order to ensure that small section of tunnel construction safety, the need for auxiliary support of small section tunnel reinforcement to resist the impact of blasting and rock produced by the instantaneous release of excavation loads generated by bias. Supporting materials, using I20 steel, wel
44、ded steel plate embedded in the grille on both ends, using high-strength bolt reinforcement. Support arrangement spacing of 0.6m, which are arranged on a grid for each Pin, arranged to extend the scope to a double-arch on each side of 1.2m, and the completion of the excavation before the big end. Th
45、e height and angle of support arrangements to ensure the smooth passage of construction machinery and equipment. Through the construction of proof, supporting the setting is necessary and effective, small-section tunnels in additional support after the convergence of scissors just 5mm. 5.5 Informati
46、on Construction In order to ensure structural safety and construction safety, in the tunnel construction process to carry out real-time monitoring measurements to study the supporting structure and the surrounding strata deformation characteristics to predict the corresponding supporting structure d
47、eformation and verify that the supporting structure is reasonable, for the information technology provide the basis for the construction. Construction Monitoring and Measurement shows a small section of the tunnel maximum settlement of 14.6mm, maximum settlement of large-section tunnel 17.2mm, struc
48、tural convergence of a maximum of 7.6mm, maximum ground subsidence of 10mm, three-arched vault in the largest settlement of tunnel excavation 22.8mm.6 Construction Summary Through this project example, proved that the use of separate programs to ensure that the wall construction of tunnels section of arch construction safety and structural safety, duration of more than a single type of wall construction program
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