CN206092016U - Stride that active fault is anti to glue tunnel preliminary bracing that slide moved - Google Patents

Abstract

A kind of primary support for anti-stick-slip tunnel across active faults. The concrete layer is a high-compression concrete layer, and a reinforced concrete layer is sprayed on the inner wall of the high-compression concrete layer; the steel arch frame is composed of multi-section I-beam connections, and the connection is located at the I-beam at the spandrel or arch foot. Its connection structure is: the end of the I-beam is welded to a rectangular connecting flange plate 1; the end of the thin-walled steel pipe is opened with a deformation gap to form a long tooth, and the end of the thin long tooth is welded to connect the flange plate 2; the I-beam The first connecting flange plate on the upper part is connected with the second connecting flange plate on the thin-walled steel pipe by bolts. The ends of the remaining I-beams are welded to a rectangular connecting flange plate 1, and the adjacent sections of I-beams are directly connected by connecting flange plates 1-bolts. This kind of primary support can absorb the energy of fault stick-slip dislocation, reduce the damage of fault dislocation to the tunnel, and effectively improve the tunnel's seismic capacity and ability to resist fault stick-slip dislocation damage; Little impact on construction progress.

Description

A kind of primary support for anti-stick-slip dislocation of tunnel across active faults

technical field

The utility model relates to a tunnel primary support for anti-stick-slip movement across active faults.

Background technique

Underground excavation tunnels are constructed according to the principle of the New Austrian Method, using composite lining support, including primary support and secondary lining. Among them, the support system composed of primary support and surrounding rock is the main bearing structure, and the secondary lining is mainly used as a safety reserve. The primary support includes a reinforced concrete layer formed by spraying on the surrounding rock, horseshoe-shaped steel arches arranged longitudinally in the reinforced concrete layer, and longitudinally connected steel bars between the steel arches.

With the acceleration of urbanization and the construction of a large number of tunnel projects, it is inevitable to encounter the problem of tunnel structures crossing active faults. Active faults refer to those faults that were newly born or had inherited movement and displacement in modern or historical periods, and may regenerate or continue to move and displace in the near future. The occurrence of earthquakes is directly related to active faults.

When active fault dislocation, especially the dislocation of sudden large deformation, i.e. stick-slip dislocation, the support structure of the subway tunnel crossing the fault section is in a complex three-dimensional stress state, and has the destructive effects of tension and compression, shear, torsion and bending . The rigid primary support of the reinforced concrete layer with the steel arch frame and the rigid secondary lining will produce three-dimensional permanent deformations such as bending, stretching, and torsion under the action of such strong damage, showing various complexities such as cracking and collapse. The form of damage seriously affects the safe operation of the tunnel.

The stick-slip dislocation of active faults has the characteristics of randomness and strong destructiveness. Therefore, for tunnel structures passing through active faults, support methods with high rigidity, strong support, and poor ductility should not be used blindly to suppress the deformation of surrounding rock, but should be adopted. Flexible support measures that can effectively adapt to fault displacement.

The Chinese patent application with the application number 201310491821.5 discloses a "tunnel support structure across active faults". The tunnel support structure has a primary lining and a foam concrete layer between the primary support and the secondary lining of the fault spanning section. And the second waterproof layer on the inner surface of the foam concrete layer. The added primary lining can partly bear the stress caused by fault creep; at the same time, the foam concrete layer provides displacement space for displacement and effectively absorbs energy, thereby reducing or even eliminating the influence of fault displacement on the tunnel and maintaining the tunnel’s Water resistance. The existing problems are: due to the addition of three concrete layers including the primary lining, the foam concrete layer, and the second waterproof layer, three times of pouring concrete are added, which increases the amount of construction, reduces construction efficiency, and seriously affects the construction progress.

Utility model content

The purpose of the invention of the utility model is to provide a tunnel primary support for anti-stick-slip movement across active faults. The initial support of the tunnel can absorb the energy of fault stick-slip dislocation, reduce the damage of fault dislocation to the tunnel, and effectively improve the tunnel's earthquake resistance and ability to resist fault stick-slip dislocation damage; Little impact on construction progress.

The technical scheme adopted by the utility model to realize the purpose of the invention is a kind of initial support for a tunnel that crosses active faults and resists stick-slip dislocation, including a horseshoe-shaped concrete layer formed by spraying on the surrounding rock, and a horseshoe-shaped concrete layer arranged vertically in the concrete layer. The steel arch frame is welded and connected by longitudinal connecting steel bars (2) between the steel arch frames, and is characterized in that:

The concrete layer is a high-compression concrete layer, and a reinforced concrete layer is formed by spraying on the inner wall of the high-compression concrete layer;

The steel arch frame is composed of multiple sections of I-beam connections, and its connection structure is:

The I-beam whose connection is located at the spandrel or arch foot, its connection structure is: the end of the I-beam is welded to a rectangular connecting flange plate 1; the end of the thin-walled steel pipe has a deformation gap to form a circumferentially arranged long Teeth, and the end of the long teeth of the thin-walled steel pipe is welded to the second rectangular connecting flange plate; the first connecting flange plate on the I-beam is connected with the second connecting flange plate on the thin-walled steel pipe by bolts.

The connection structure of the remaining I-beams is: the end of the I-beam is welded to a rectangular connecting flange plate 1, and the adjacent sections of I-beams are directly connected by connecting flange plates 1-bolts.

Compared with the prior art, the beneficial effect of the tunnel initial support of the utility model is:

1. The inner layer of the primary support is a reinforced concrete structure, and the outer layer is a steel arch high-compression concrete layer including a flexible connection structure. When the tunnel structure bears normal loads, the thin-walled steel pipes with deformation gaps do not yield, which can ensure the strength of the entire lining and meet the structural safety under normal use conditions.

2. When the stick-slip dislocation occurs on the active fault, the load of the supporting structure increases, and the load mainly increases at the parts with large bending moments such as the spandrel and arch foot of the steel arch frame. The long teeth on the thin-walled steel pipes buried in these parts along the tunnel The circumferential direction of the thin-walled steel pipe (the axial direction of the thin-walled steel pipe) is compressed, thereby actively increasing the deformation of the steel arch and the entire concrete structure, which can reduce the stress increment of the supporting structure, and can make the lining force more uniform, which can greatly reduce Permanent cracks and failure of the lining when the fault occurs. In a word, the utility model contains a steel arch frame with thin-walled flexible steel pipes and a high-compression concrete layer to form a flexible support layer, forming a lining structure of "soft outside and rigid inside", achieving the effect of energy absorption and earthquake resistance.

3. The utility model only needs to add a flexible thin-walled steel pipe structure in the connection part of the steel arch frame where the bending moment is large; and change the original reinforced concrete layer into a high-compression concrete layer, and then add a layer of reinforced concrete layer, In terms of construction volume, only one layer of high-compression concrete layer is added, and the total construction volume is far lower than the construction volume of adding three concrete layers and pouring concrete three times. The increased construction volume is small and affects the construction progress. Small impact.

Further, the thin-walled steel pipe of the present utility model is also fitted with the small mouth of the tapered steel sleeve, and the tapered steel sleeve covers the long teeth of the thin-walled steel pipe; The second welding of the blue plate.

In this way, the tapered sleeve covers the long teeth of the thin-walled steel pipe, which can prevent the radial shear movement of the thin-walled steel pipe during the horizontal displacement of the active fault, resulting in shear failure of the steel arch, and at the same time does not hinder the thin-walled steel pipe. The long teeth of the wall steel pipe undergo compressive deformation along the tunnel circumference to achieve the function of energy absorption and earthquake resistance.

Furthermore, the thickness of the high-compression concrete layer of the present invention is 18-30cm, and the thickness of the reinforced concrete layer is 18-30cm; the first connecting flange plate and the second connecting flange plate are 24cm×20cm×1.5cm The steel flange plate; the longitudinal connecting steel bar is a threaded steel bar with a diameter of 2.2cm; the diameter of the thin-walled steel pipe is 15cm, the length is 30cm-50cm, and the wall thickness is 2.0cm; the length of the long teeth is 8cm -16cm.

The longitudinal spacing of adjacent steel arches is 1.0m long, and the circumferential spacing between adjacent longitudinal connecting steel bars is 1.0m.

These selected parameters can not only ensure that the tunnel structure has sufficient strength, but also meet the structural safety under normal use conditions. At the same time, it can form a lining structure of "soft on the outside and rigid on the inside" to achieve the effect of energy absorption and earthquake resistance, and effectively reduce the permanent cracks and damage of the lining when the fault occurs.

The construction method of the primary support of the present utility model is:

a, the steel arches are framed on the surrounding rock wall of the excavation, and the longitudinal connecting steel bars are welded between adjacent steel arches;

b. spraying high-compression concrete to the excavated surrounding rock wall to form the high-compression concrete layer on the surrounding rock wall, and the high-compression concrete layer completely covers the steel arch;

c. After the high-compression concrete layer is solidified, tie steel bars on the inner wall of the high-compression concrete layer, and then spray concrete to form the reinforced concrete layer, that is, complete the construction of the initial support of the tunnel.

The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic diagram of a longitudinal section structure of an embodiment of the utility model.

Fig. 2 is a sectional view along line A-A of Fig. 1 .

FIG. 3 is a partially enlarged view of part C in FIG. 2 .

detailed description

Example

Figures 1-3 show that a specific embodiment of the present invention is an initial support for a tunnel that crosses active faults and resists stick-slip dislocation, a kind of tunnel initial support that crosses active faults and resists stick-slip dislocation, It includes a horseshoe-shaped concrete layer formed by spraying on the surrounding rock, and horseshoe-shaped steel arches arranged longitudinally in the concrete layer. The steel arches are connected by welding longitudinally connecting steel bars 2, which are characterized in that:

The concrete layer is a high-compression concrete layer 3, and a reinforced concrete layer 4 is formed by spraying on the inner wall of the high-compression concrete layer 3;

The steel arch frame is composed of multiple sections of I-beams 11 connected, and its connection structure is:

Fig. 2, Fig. 3 show, the I-beam 11 that the junction is positioned at spandrel or arch foot position, its connection structure is: the end of I-beam 11 is welded rectangular connection flange plate-12a; Thin-walled steel pipe 14 There are deformation gaps at the end to form long teeth 14a arranged in the circumferential direction, and the end of the long teeth 14a of the thin-walled steel pipe 14 is welded to a rectangular connecting flange plate 2 12b; The connecting flange plate 2 12b on the wall steel pipe 14 is bolted.

The connection structure of the rest of the I-beams 11 is: the end of the I-beams 11 is welded to a rectangular connecting flange plate-12a, and the I-beams 11 of adjacent sections are directly connected by bolts of the connecting flange plates-12a.

Figure 2 and Figure 3 show that the thin-walled steel pipe 14 of this example is also fitted with the small opening of the tapered steel sleeve 15, and the tapered steel sleeve 15 covers the long teeth 14a of the thin-walled steel pipe 14; The mouth edge of the big mouth of sleeve 15 is welded with connecting flange plate two 12b.

The thickness of the high-compression concrete layer 3 of this example is 18-30cm, and the thickness of the reinforced concrete layer 4 is 18-30cm; Described connection flange plate one 12a and connection flange plate two 12b are 24cm * 20cm * 1.5cm steel flange plate; the longitudinal connecting steel bar 2 is screw steel with a diameter of 2.2cm; the diameter of the thin-walled steel pipe 14 is 15cm, the length is 30cm-50cm, and the wall thickness is 2.0cm; the long teeth 14a The length is 8cm-16cm.

The longitudinal distance between adjacent steel arches is 1.0m long, and the circumferential distance between adjacent longitudinal connecting steel bars 2 is 1.0m.

In this example, the construction method of the primary support for the anti-stick-slip dislocation of the tunnel across the active fault is as follows:

a, the steel arches are framed on the surrounding rock wall of the excavation, and the longitudinal connecting steel bars 2 are welded between adjacent steel arches;

b. Spraying high-compression concrete to the excavated surrounding rock wall to form the high-compression concrete layer 3 on the surrounding rock wall, and the high-compression concrete layer 3 completely covers the steel arch;

c. After the high-compression concrete layer 3 is solidified, tie steel bars on the inner wall of the high-compression concrete layer 3 and then spray concrete to form the reinforced concrete layer 4, which is to complete the construction of the initial support of the tunnel.

Claims (3)

1. a kind of Tunnel moved across the anti-stick slide of active fault, is included on country rock and sprays the horseshoe-shaped mixed of formation The horseshoe-shaped steel arch-shelf of longitudinal arrangement in solidifying soil layer, concrete layer, is connected between steel arch-shelf by longitudinally connected reinforcing bar (2) welding Connect, it is characterised in that：

Described concrete layer is high compression concrete layer (3), and also injection is formed on the inwall of high compression concrete layer (3) There is reinforced concrete floor (4)；

Described steel arch-shelf is connected and composed by multistage I-steel (11), and its attachment structure is：

Junction is located at the I-steel (11) at spandrel or arch springing position, and its attachment structure is：The end welding square of I-steel (11) The adpting flange plate one (12a) of shape；The end of thin-wall steel tube (14) is provided with and becomes the long tooth (14a) that v notch v forms circumferential array, And the adpting flange plate two (12b) of rectangle is welded in long tooth (14a) end of thin-wall steel tube (14)；Connection method on I-steel (11) Adpting flange plate two (12b) bolt connection on blue plate one (12a) and thin-wall steel tube (14)；

The attachment structure of remaining I-steel (11) is：The adpting flange plate one (12a) of rectangle is welded in the end of I-steel (11), The I-steel (11) of adjacent segment directly passes through adpting flange plate one (12a) bolt connection.

2. it is according to claim 1 it is a kind of across the anti-stick slide of active fault move Tunnel, it is characterised in that：Institute The thin-wall steel tube (14) stated also with the osculum fit of taper steel bushing (15), taper steel bushing (15) is by the length of thin-wall steel tube (14) Tooth (14a) is covered；And the opening's edge of the big mouth of taper steel bushing (15) is welded with adpting flange plate two (12b).

3. it is according to claim 1 it is a kind of across the anti-stick slide of active fault move Tunnel, it is characterised in that：

The thickness of described high compression concrete layer (3) is 18-30cm, and the thickness of reinforced concrete floor (4) is 18-30cm；Institute The adpting flange plate one (12a) and adpting flange plate two (12b) stated are the steel flanges plate of 24cm × 20cm × 1.5cm；Institute The longitudinally connected reinforcing bar (2) stated for diameter 2.2cm screw-thread steel；A diameter of 15cm of described thin-wall steel tube (14), length is 30cm-50cm, wall thickness is 2.0cm；The length of long tooth (14a) is 8cm-16cm；

The longitudinal pitch of adjacent steel arch-shelf is long 1.0m, and the circumferential distance between adjacent longitudinally connected reinforcing bar (2) is 1.0m.