阅读说明：本技术 一种隧道群开挖方法 (Tunnel group excavation method ) 是由 吴春伟 骆俊晖 周祥 黄海峰 廖来兴 畅振超 莫鹏 刘豪斌 覃珏莹 曾富权 王诗 于 2021-06-16 设计创作，主要内容包括：本发明公开了一种隧道群开挖方法,属于隧道施工技术领域,所述方法包括确定先导洞位置,从先导洞先施工至临时横通道位置,施工临时横通道,A型断面施工,并从A型断面反向施工,剩余隧道施工。本发明在无法利用临时竖井和临时横通道情况下,以先导洞施工至大断面隧道临时通道,为大断面隧道掘进提供施工作业面,避免小断面隧道向大断面隧道掘进,保证施工安全,先导洞初支结构采用波纹钢+混凝土结构,后续破除,可回收波纹钢,实现重复利用,节约资源。(The invention discloses a tunnel group excavation method, which belongs to the technical field of tunnel construction. According to the invention, under the condition that the temporary vertical shaft and the temporary transverse channel cannot be utilized, the pilot tunnel is constructed to the temporary channel of the large-section tunnel, so that a construction working surface is provided for the tunneling of the large-section tunnel, the small-section tunnel is prevented from tunneling to the large-section tunnel, the construction safety is ensured, the primary support structure of the pilot tunnel adopts a corrugated steel + concrete structure, the corrugated steel can be recovered after the follow-up breaking, the reutilization is realized, and the resources are saved.)

1. A tunnel group excavation method is characterized by comprising the following steps:

step 1: determining the position of a pilot tunnel, selecting a shortest line from a tunnel line to an A-type section tunnel from a shield well as the pilot tunnel, wherein the section of the pilot tunnel is a D-type section, and the D-type section is subjected to primary tunnel support and secondary tunnel lining structure;

step 2: constructing to a temporary transverse channel position from a pilot tunnel, and completing a primary support structure, wherein the pilot tunnel uses corrugated steel plates and concrete as the primary support structure;

and step 3: constructing a temporary transverse passage to finish a primary support structure of the temporary transverse passage, and using corrugated steel plates and concrete as the primary support structure;

and 4, step 4: constructing an A-shaped section, constructing an advanced large pipe shed and a small pipe advanced support, constructing an A-shaped section tunnel from a temporary transverse passage in a reverse direction, then continuing to construct forwards, and simultaneously beginning to tunnel from a shield well to finish other tunnels;

and 5: and (3) constructing the rest tunnel, starting to build an advanced large pipe shed and a small pipe advanced support, constructing the E, C type section tunnel to the position of the temporary transverse passage, finishing the primary support and the secondary lining structure of the tunnel, and expanding and digging the position of the temporary transverse passage to form the A type tunnel section.

2. The method of excavating a tunnel group according to claim 1, wherein: in the step 2, the temporary transverse passage is tunneled at a fixed angle from the position of the A-shaped section close to the position of the right shield well, namely the shortest line is reached at the position of the A-shaped section, the A-shaped section climbs with a gradient of two thousandths, the D-shaped section is an ascending slope, and the maximum gradient of the ascending slope is 2.97%.

3. The method of excavating a tunnel group according to claim 2, wherein: in step 2, when the plugging wall is constructed at the joint of the D-type section and the A-type section, a composite lining is adopted, a phi 22 mortar anchor rod is adopted for primary support, L is 3.5m, the distance is 1000 multiplied by 1000mm, the quincunx arrangement is adopted, cement paste is injected after primary support is backed, waterproof reinforced concrete is adopted for secondary lining of the plugging wall, the secondary lining and the secondary lining of the tunnel are simultaneously poured, and a waterproof layer is arranged between the primary support and the secondary lining of the plugging wall and is connected with a waterproof layer of the tunnel section.

4. The method of excavating a tunnel group according to claim 3, wherein: and 4, when the construction is performed reversely from the A-shaped section, after the A-shaped section is constructed, constructing the B-shaped section, and after the B-shaped section is constructed, constructing the F-shaped section and finally forming the C-shaped section.

5. The method of excavating a tunnel group according to claim 4, wherein: in step 5, constructing the E-shaped section and then constructing the C-shaped section on the middle two lines, constructing the F-shaped section, and constructing the C-shaped section and then constructing the B-shaped section on the two sides.

6. The method of excavating a tunnel group according to claim 5, wherein: the construction method comprises the steps of constructing the A-type section by a double-side-wall pit guiding method, constructing the B-type section, the C-type section and the D-type section by a step method, reinforcing the opening of a construction vertical shaft by three steel frames in parallel, adding a temporary support when excavating the intersection, constructing two lining reinforced concrete in a 10m range of the interval tunnel after opening the interval tunnel, ensuring the stable structure and the construction safety of the intersection during construction, constructing a vault advanced small conduit or an advanced large conduit shed to reinforce surrounding rocks when a channel enters the tunnel, performing advanced forecasting by a TSP advanced geological forecasting system and an advanced probe hole before tunnel construction, forecasting and judging by combining geological conditions, development rules, trends and precursors disclosed by a tunnel face, and correspondingly optimizing and adjusting measures according to the advanced geological forecasting results to establish an emergency plan so as to ensure the construction safety and the structural safety.

Technical Field

The invention relates to the technical field of tunnel construction, in particular to a tunnel group excavation method.

Background

The tunnel excavation method generally implements excavation according to a sequence. Tunneling from the inlet end to the outlet end of the tunnel, the tunnel lining structure is single, the design of three tunnel lining structures cannot be exceeded generally, the construction difficulty is reduced, and the tunnel construction safety is guaranteed. The process conversion between different tunnel section sizes is also very important, and tunnel stress and deformation are small due to the fact that tunneling is generally conducted on the tunnel with the small section size according to the large section, so that the construction organization is more reasonable, and the construction process is safer.

When the tunnel lining structure type is more, generally adopt interim shaft + interim cross passage mode, increase a plurality of construction sections, carry out the blasting tunnelling simultaneously, raise the efficiency. However, due to various reasons such as shortage of land resources, construction cannot be performed in the temporary vertical shaft and temporary transverse passage manner, so that construction organization is difficult, construction efficiency is low, and construction safety is difficult to guarantee.

Disclosure of Invention

The invention aims to provide a tunnel group excavation method, which solves the technical problems in the background technology. Due to various reasons such as land resource shortage and the like, a plurality of construction operation surfaces can not be provided for main tunnel construction by applying temporary vertical shafts and temporary transverse channels, so that the main tunnel large-section tunnel is difficult to excavate and cannot be implemented. The method comprises the steps of constructing a pilot tunnel to a temporary transverse channel design position by using a positive tunnel shield well, constructing a large-section tunnel excavation temporary working chamber, and reversely excavating the large-section tunnel. Meanwhile, other working surfaces are provided for the mine tunnel construction by utilizing the station structure, and the construction efficiency is further improved.

A method of excavating a group of tunnels, the method comprising the steps of:

step 1: determining the position of a pilot tunnel, selecting a shortest line from a tunnel line to an A-type section tunnel from a shield well as the pilot tunnel, wherein the section of the pilot tunnel is a D-type section, and the D-type section is subjected to primary tunnel support and secondary tunnel lining structure;

step 2: constructing to a temporary transverse channel position from a pilot tunnel, and completing a primary support structure, wherein the pilot tunnel uses corrugated steel plates and concrete as the primary support structure;

and step 3: constructing a temporary transverse passage to finish a primary support structure of the temporary transverse passage, and using corrugated steel plates and concrete as the primary support structure;

and 4, step 4: constructing an A-shaped section, constructing an advanced large pipe shed and a small pipe advanced support, constructing an A-shaped section tunnel from a temporary transverse passage in a reverse direction, then continuing to construct forwards, and simultaneously beginning to tunnel from a shield well to finish other tunnels; the two A-shaped section tunnels are small clear distance tunnels, and rock strata are clamped in less disturbance in the construction process, so that the reinforcement quality of the tunnel is improved.

And 5: and (3) constructing the rest tunnel, starting to build an advanced large pipe shed and a small pipe advanced support, constructing the E, C type section tunnel to the position of the temporary transverse passage, finishing the primary support and the secondary lining structure of the tunnel, and expanding and digging the position of the temporary transverse passage to form the A type tunnel section.

Further, in step 2, the temporary transverse passage is tunneled at a fixed angle from the position of the A-shaped section close to the position of the right shield well, namely the shortest line is reached at the position of the A-shaped section, the A-shaped section climbs with a gradient of two thousandths, the D-shaped section is an ascending slope, and the maximum gradient of the ascending slope is 2.97%.

Further, in step 2, when constructing the bulkhead wall at the joint of the D-type section and the A-type section, a composite lining is adopted, a phi 22 mortar anchor rod is adopted for primary support, L is 3.5m, the distance is 1000 multiplied by 1000mm, quincunx arrangement is adopted, cement paste is injected after primary support is backed, waterproof reinforced concrete is adopted for secondary lining of the bulkhead wall, the secondary lining is simultaneously injected with secondary lining of the tunnel, and a waterproof layer is arranged between the primary support and the secondary lining of the bulkhead wall and is connected with a waterproof layer of the tunnel section.

Further, in step 4, when the construction is performed in the reverse direction from the a-shaped cross section, the B-shaped cross section is constructed after the a-shaped cross section is completed, the F-shaped cross section is constructed after the B-shaped cross section is completed, and finally the C-shaped cross section is formed.

Further, in step 5, an E-shaped section is constructed on the middle two lines, then a C-shaped section is constructed, finally an F-shaped section is constructed, and a B-shaped section is constructed on the two sides of the C-shaped section.

Furthermore, the A-shaped section is constructed by a double-side-wall pit guiding method, the B-shaped section, the C-shaped section and the D-shaped section are constructed by a step method, three steel frames are adopted at the opening of the construction vertical shaft for strengthening in parallel, when the intersection is excavated, temporary supports are additionally arranged, after the interval tunnel is excavated, the second liner reinforced concrete is firstly applied within 10m of the interval tunnel after the excavation, so that the stable structure and the construction safety of the intersection during the construction period are ensured, when a channel enters the tunnel, firstly, a vault advanced small conduit or an advanced large pipe shed is constructed to reinforce surrounding rocks, a TSP advanced geological prediction system and advanced exploration holes are adopted to carry out advanced geological prediction before tunnel construction, geological conditions, development rules, trends and precursors disclosed by a tunnel face are combined to carry out prediction and judgment, and correspondingly optimizing and adjusting measures according to the advanced geological prediction result, and formulating an emergency plan to ensure construction safety and structural safety.

By adopting the technical scheme, the invention has the following technical effects:

according to the invention, under the condition that the temporary vertical shaft and the temporary transverse passage cannot be utilized, the pilot tunnel is constructed to the design position of the large-section temporary working room by using the main tunnel shield well, so that a construction working surface is provided for the tunneling of the large-section tunnel, the tunneling of the small-section tunnel to the large-section tunnel is avoided, the construction safety is ensured, the primary support structure of the pilot tunnel adopts a corrugated steel + concrete structure, the corrugated steel can be recovered through subsequent breaking, the recycling is realized, and the resources are saved.

Drawings

FIG. 1 is a schematic view of the construction structure of the present invention.

FIG. 2 is a mesh partition of the planar finite element analysis of the present invention.

FIG. 3 is a cloud diagram of horizontal displacement of the full section of the left tunnel before two-lining construction.

FIG. 4 is a cloud diagram of horizontal displacement after the completion of the two liners of the full section of the left-hole tunnel.

Fig. 5 is a longitudinal cross-sectional view of a temporary transverse channel of the present invention.

FIG. 6 is a front longitudinal cross-sectional view of the present invention.

Reference numbers in the figures: 1-left line shield well; 2-right shield well; a 3-D type cross section; 4-C type cross section; 5-F type cross section; 6-B type cross section; 7-A type cross section; 8-E type cross section; 9-temporary transverse channel.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, preferred embodiments are given and the present invention is described in further detail. It should be noted, however, that the numerous details set forth in the description are merely for the purpose of providing the reader with a thorough understanding of one or more aspects of the present invention, which may be practiced without these specific details.

A tunnel group excavation method is shown in figures 1-6, the concrete construction process is indicated by arrows in figure 1, the sequence is that firstly, a middle lane is selected from a right line shield shaft 2 to be constructed, a D-shaped section 3 is constructed as shown in the figure, the construction is directly carried out on a temporary transverse passage 9, after the construction of the temporary transverse passage 9 is completed, an A-shaped section 7 is constructed, then the construction is carried out reversely from the A-shaped section 7 to a B-shaped section 6, and then to an F-shaped section 5 and a C-shaped section 4. The construction at the other end is that an E-shaped section 8 and C-shaped sections 4 at two sides are constructed firstly, an F-shaped section 5 is constructed after the middle E-shaped section 8 is constructed, and a B-shaped section 6 is constructed after the C-shaped sections 4 at two sides are constructed.

(1) Determining the pilot hole position: and (3) avoiding tunneling a long line to the tunnel with the A-shaped section, and selecting the position from the right shield well to construct the tunnel with the D-shaped section to the A-shaped section to complete the primary support and secondary lining structure of the tunnel.

(2) Use D type section to construct to interim cross passage position earlier as guide's hole to accomplish just a structure, guide's hole utilizes deck slab and concrete as just a structure, makes things convenient for the later stage to demolish the recovery, realizes green construction, reuse, resources are saved's purpose.

(3) Constructing a temporary transverse channel: accomplish interim horizontal passage and just prop up the structure, utilize corrugated steel plate and concrete as just propping up the structure, make things convenient for the later stage to demolish the recovery, realize green construction, reuse, resources are saved's purpose.

(4) Construction of an A-type large section: and (3) constructing an advanced large pipe shed and a small pipe advanced support, constructing an A-shaped section tunnel reversely, then continuing to construct forwards, simultaneously tunneling the tunnel from a shield well, completing other tunnels, wherein a primary support structure of the advanced tunnel needs to be broken, and recovering the corrugated steel plate.

(5) And (3) constructing the rest tunnels: the end of the station begins to build an advanced large pipe shed and a small pipe advanced support, a tunnel with E, C type cross section is constructed to the position of an temporary transverse passage, the primary support and a secondary lining structure of the tunnel are completed, and the position of the temporary transverse passage is expanded and dug to form an A type tunnel cross section.

The specific construction scheme of the pilot hole is as follows: taking the D-shaped section as a pilot hole section form; tunneling to a temporary transverse passage (the shortest route reaching the position of the A-shaped section) at a certain angle from the position of the A-shaped section close to the position of the right shield well; the A-type section climbs with a gradient of two thousandths, the D-type section can ascend or descend (considering the drainage problem, the ascending is recommended), and the maximum gradient of the ascending is as follows: imax 1.639m/55.2m 100% ═ 2.97%.

Different tunnel sections are connected and designed: the tunnel structure adopts a composite lining. The primary support adopts 22 mortar anchor rods, L is 3.5m, the distance is 1000 multiplied by 1000mm, the arrangement is in a quincunx shape, and cement slurry is injected after primary support is carried out; the second lining of the blocking wall is made of waterproof reinforced concrete and is poured with the second lining of the tunnel at the same time. The waterproof grade of the structure is two levels, and a waterproof layer is arranged between the primary support of the plug wall and the secondary lining and is connected with a waterproof layer of the section of the tunnel. After the tunnel is excavated, the tunnel is supported in time and closed to form a ring in time; the second lining should be constructed in time, the inverted arch is constructed firstly, and the arch wall part is integrally molded by adopting a template trolley. The gap between the second lining of the arch part of the composite lining of the tunnel and the waterproof layer is filled by injecting cement paste under pressure, and the grouting pressure is controlled properly. In construction, on-site monitoring and measuring work and geological advanced forecasting work are enhanced, and information is fed back in time so as to adjust related design parameters.

The transverse channel is connected with other section tunnels: the stress condition at the intersection is complex, the A-type section is constructed by adopting a double-side-wall pit guiding method, the B, C, D-type section is constructed by adopting a step method, and management and construction are carried out according to the principles of advancing, strict grouting, short excavation, strong support, duty measurement and early sealing in the construction process strictly, so that the safety is ensured. And three steel frames are adopted at the opening of the construction shaft for strengthening in parallel. When the intersection is excavated, temporary supports are additionally arranged as necessary according to specific conditions and measurement results, and after the interval tunnel is excavated, second-lining reinforced concrete is firstly applied within 10m of the interval tunnel after the excavation, so that the stable structure and the construction safety of the intersection during construction are ensured. The anchor bolt driving angle is determined according to the current situation of the rock stratum and the fracture direction. When the channel enters the tunnel, a vault advanced small conduit or an advanced large pipe shed is firstly constructed to reinforce the surrounding rock. The method comprises the steps of carrying out advanced geological forecast by adopting a TSP advanced geological forecast system and an advanced exploring hole before tunnel construction, carrying out forecast and judgment by combining geological conditions, development rules, trends and precursors disclosed by a tunnel face, correspondingly optimizing adjustment measures according to the advanced geological forecast result, and formulating an emergency plan so as to ensure construction safety and structural safety.

Numerical simulation of the excavation process of the small-clear-distance and large-section tunnel is carried out, as shown in fig. 2, the excavation and supporting process of the model tunnel is constructed according to the double-side-wall pit guiding method, and the calculation results are as follows, as shown in fig. 3-4.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.