CN110107319A - A method of utilizing embedding arch shotcrete composite structure Strengthening Tunnel lining cutting - Google Patents

Abstract

The invention relates to the technical field of tunnel reinforcement, in particular to a method for reinforcing tunnel lining by utilizing an arch-embedded bolt-shot composite structure. 1) Open a circular trapezoidal groove on the original lining, and embed the I-shaped steel arch; 2) Set up a longitudinal horizontal groove along the longitudinal direction of the tunnel, set longitudinal connecting ribs in the longitudinal horizontal groove, and weld them on the adjacent I-shaped steel arch 3) Filling and grouting the annular trapezoidal grooves and longitudinal horizontal grooves with concrete; 4) Setting up prestressed anchors in each grid reinforcement area of the tunnel lining to form a ring of stable compression belts; 5) Using high pressure The tunnel lining is flushed with water guns, and a layer of concrete is sprayed on the lining to form an inlaid arch-anchor-shotcrete composite structure for reinforcing the tunnel lining. The invention can reinforce the cracked, peeled or collapsed lining and maintain the stability of the tunnel structure.

Description

A method of reinforcing tunnel lining by using arch-embedded bolt-shot composite structure

technical field

The invention relates to the technical field of tunnel reinforcement, in particular to a method for reinforcing tunnel lining by utilizing an arch-embedded bolt-shot composite structure.

Background technique

With the rapid development of the national economy, the construction of my country's transportation infrastructure has also developed rapidly, among which tunnel construction has become an indispensable part of my country's transportation network construction. However, various diseases occurred during the operation of the tunnel, such as lining damage, invert or pavement protrusion, lining leakage, etc., among which the damage to the tunnel lining is the most significant.

The damage of tunnel lining structure is mainly manifested as: lining cracking and deformation, piece peeling off, large piece slumping and so on. The reasons can be summarized as geological factors (such as weak surrounding rock, stratum bias, landslides, etc.), imperfect design, construction reasons and other human factors (such as borrowing soil near the tunnel, mining, etc.). Tunnel lining is the main body of the project to withstand the formation pressure and prevent the surrounding rock from deforming and slumping. The size of the formation pressure mainly depends on the engineering geology, the hydrogeological conditions of the building and the physical and mechanical properties of the surrounding rock, as well as the construction method and whether the supporting lining is timely. As well as the quality of the project and other factors. Due to deformation pressure, loosening pressure, stratum longitudinal distribution along the tunnel and uneven mechanical properties, temperature and shrinkage stress, surrounding rock expansion or frost heave pressure, corrosive medium, human factors during construction, operation The circulation of vehicles causes cracks, deformations and even cracks in the tunnel lining structures. The crack of the tunnel lining destroys the stability of the tunnel structure, affects the normal use of the tunnel, and even endangers the traffic safety.

SUMMARY OF THE INVENTION

The present invention aims to provide a method for reinforcing tunnel lining with an arch-embedded bolt-shot composite structure, so as to reinforce the cracked, peeled or collapsed lining and maintain the stability of the tunnel structure.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a method for reinforcing tunnel lining by utilizing the embedded arch-anchor-shotcrete composite structure, comprising the following steps:

1) On the inside of the original lining along the longitudinal direction of the tunnel, there are annular trapezoidal grooves distributed along the circumferential direction of the original lining. The slot width of the annular trapezoidal groove is smaller than the width of the groove bottom. Shaped steel arch;

2) A plurality of longitudinal horizontal grooves distributed along the longitudinal direction of the tunnel are opened on the inner side of the original lining and between two adjacent annular trapezoidal grooves. The grooves are connected to form a grid-like slotted structure on the inner side of the original lining by the annular trapezoidal groove and the longitudinal horizontal groove; the longitudinal connecting ribs are embedded in the longitudinal horizontal grooves, and the two ends of the longitudinal connecting ribs are welded and fixed on both sides respectively. The web of the I-shaped steel arch;

3) Pour concrete into the annular trapezoidal groove and the longitudinal horizontal groove respectively to form a concrete filling layer, and inject cement mortar into the gap between the concrete filling layer and the original lining to form a grouting filling layer;

4) Insert a prestressed bolt at the center of all grids in the grid-like slotted structure in step 2), and insert the bolt into the surrounding rock of the tunnel through the original lining;

5) Spray a layer of concrete to the inside of the original lining to form a concrete spray layer, which is composed of I-shaped steel arches, longitudinal connecting bars, concrete filling layers, grouting filling layers, anchor rods and concrete spray layers to form a network of steel bars Concrete structure, that is, the embedded arch bolt-shot composite structure used to strengthen the tunnel lining.

Preferably, in step 1), a plurality of I-shaped steel arches are embedded in the same annular trapezoidal groove segmentally, and the corresponding ends of the adjacent two I-shaped steel arches are welded and fixed with steel backing plates. Bolt holes are provided on the plate, and two I-shaped steel arches are fixedly connected by bolts.

Preferably, the longitudinal horizontal grooves in step 2) are rectangular grooves.

Preferably, the ratio of cement to sand in the cement mortar in step 3) is 1:0.5, and the ratio of water to cement is between 0.8 and 1.0.

Preferably, in step 3), a grouting hole is opened on the concrete filling layer, and cement mortar is injected into the gap between the concrete filling layer and the original lining through the grouting hole, and the working pressure of the grouting hole is controlled at 0.3~0.5MPa between.

Preferably, the thickness of the concrete sprayed layer in step 5) is 8-12 cm, and the inner side of the original lining is rinsed before the concrete is sprayed.

beneficial effect

The main technical measures of the present invention are to cut out annular trapezoidal grooves and longitudinal horizontal grooves on the original lining of the tunnel, embed the I-shaped steel arches and longitudinal connecting bars respectively, and perform concrete pouring and grouting filling; Lining each grid reinforcement area is provided with prestressed bolts and a new layer of concrete lining is sprayed. After being reinforced by the present invention, under the condition of retaining the original lining bearing capacity, the tunnel lining can be reinforced by using the inlaid arch and the bolt and shotcrete support, and the tunnel clearance is not obviously reduced, which has outstanding advantages. At the same time, the invention has less mechanical equipment investment, simple construction process, strong operability, less one-time investment, and saves construction cost.

Description of drawings

Fig. 1 is the front view of the embedded arch-bolt shotcrete composite reinforcement structure in the present invention;

Fig. 2 is the A-A direction view in Fig. 1;

Fig. 3 is the side view of the embedded arch-bolt shotcrete composite reinforcement structure in the present invention;

Marked in the figure: 1. Original lining, 2. Grouting filling layer, 3. Concrete filling layer, 4. Concrete spraying layer, 5. I-shaped steel arch, 6. Steel backing plate, 7. Circumferential trapezoidal groove, 8 , Longitudinal horizontal groove, 9, Longitudinal connecting ribs, 10, Anchor rod.

Detailed ways

As shown in Fig. 1 to Fig. 3, a method for reinforcing tunnel lining using an arch-embedded bolt-shot composite structure of the present invention comprises the following steps:

1) First, annular trapezoidal grooves 7 are evenly spaced along the longitudinal direction of the tunnel on the inner side of the original lining 1 , and any annular trapezoidal groove 7 is opened along the circumferential direction of the original lining 1 . The cross-section of the annular trapezoidal groove 7 is an inverted trapezoid, and the width of the groove at the lower part is smaller than the width of the groove bottom at the upper part. Then, a plurality of I-shaped steel arches 5 are embedded in the annular trapezoidal groove 7, and the corresponding ends of the adjacent two I-shaped steel arches 5 are welded and fixed with steel backing plates 6, and the steel backing plates 6 are provided with bolt holes. And the two I-shaped steel arches 5 are fixedly connected by bolts. A gap is maintained between the outside of the I-shaped steel arch 5 and the annular trapezoidal groove 7 .

2) First, a plurality of longitudinal horizontal grooves 8 are opened evenly spaced on the inner side of the original lining 1 and located between two adjacent annular trapezoidal grooves 7 . The longitudinal horizontal grooves 8 are rectangular in cross section and are distributed along the longitudinal direction of the tunnel. Both ends of any longitudinal horizontal groove 8 are respectively connected with the two annular trapezoidal grooves 7 on both sides, so that the annular trapezoidal groove 7 and the longitudinal horizontal groove 8 together form a grid-like slotted structure inside the original lining 1 . Then, the longitudinal connecting ribs 9 are embedded in the longitudinal horizontal grooves 8, and the two ends of the longitudinal connecting ribs 9 are welded and fixed on the webs of the I-shaped steel arches 5 on both sides respectively.

3) First, pour concrete into the gap between the wage steel arch and the annular trapezoidal groove 7 and the gap between the longitudinal connecting rib 9 and the longitudinal horizontal groove 8 respectively to form the concrete filling layer 3 . Then, grouting holes are drilled on the concrete filling layer 3 , and cement mortar is injected into the gap between the concrete filling layer 3 and the original lining 1 through the grouting holes to form the grouting filling layer 2 . The ratio of cement and sand in the cement mortar is 1:0.5, the ratio of water and cement is between 0.8 and 1.0, and the working pressure of the grouting hole is controlled between 0.3 and 0.5 MPa.

4) Insert the prestressed bolt 10 at the center of all grids in the grid-like slotted structure in step 2), and insert the bolt 10 into the surrounding rock of the tunnel through the original lining 1 to form a ring of stability compression tape.

5) Use a high-pressure water gun to rinse the inside of the original lining 1, and then spray a layer of 8-12cm concrete to the inside of the original lining 1 to form a concrete spray layer 4, which can be composed of I-shaped steel arches 5, longitudinal connecting bars 9, concrete filling layer 3. The grouting filling layer 2, the anchor rod 10 and the concrete spray layer 4 together form a layer of mesh-like reinforced concrete structure, that is, the embedded arch-anchor-shotcrete composite structure used for reinforcing the tunnel lining.

The above process reciprocates to form a new lining inside the tunnel. During the reinforcement process, attention should be paid to controlling the length of each construction section to avoid large deformation of the surrounding rock.

Claims (6)

1. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting, it is characterised in that: the following steps are included:

1) it, opens up at the interior lateral edge tunnel longitudinal direction interval of former lining cutting (1) along the circumferential trapezoidal of former lining cutting (1) circumferential direction distribution The width of rebate of slot (7), circumferential dovetail groove (7) is less than its slot bottom width, and insertion arc is I-shaped in circumferential dovetail groove (7) Steel arch-shelf (5)；

2), the location interval on the inside of former lining cutting (1) and between two neighboring circumferential dovetail groove (7) opens up a plurality of along tunnel The vertical equity slot (8) of longitudinal direction distribution, the both ends of vertical equity slot (8) respectively with two of two sides circumferential dovetail grooves (7) It is connected, latticed notching construction is collectively formed by circumferential dovetail groove (7) and vertical equity slot (8) on the inside of former lining cutting (1)； The longitudinally connected muscle (9) of insertion in vertical equity slot (8), and the both ends of longitudinally connected muscle (9) are respectively welded and are fixed on two sides I shaped steel arch (5) web on；

3), in Xiang Huanxiang dovetail groove (7) and vertical equity slot (8) respectively casting concrete to form Concrete Filled layer (3), to Interstitial site injection cement mortar between Concrete Filled layer (3) and former lining cutting (1) is to form slip casting filled layer (2)；

4), prestressed anchor (10) are inserted into the center of all grids in the latticed notching construction in step 2, And so that anchor pole (10) is run through former lining cutting (1) and be inserted into tunnel surrounding；

5), to one layer concrete of injection on the inside of former lining cutting (1) to form concrete ejection layer (4), by i shaped steel arch (5), Longitudinally connected muscle (9), Concrete Filled layer (3), slip casting filled layer (2), anchor pole (10) and concrete ejection layer (4) common shape At one layer of netted reinforced concrete structure, that is, it is used for the embedding arch shotcrete composite structure of Strengthening Tunnel lining cutting.

2. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting according to claim 1, feature It is: in step 1), more i shaped steel arches (5) of segmentation insertion, adjacent two I-shapeds in same circumferential direction dovetail groove (7) The corresponding end of shaped steel arch (5) is welded with billet (6), is offered bolt hole on billet (6) and is passed through bolt Two i shaped steel arches (5) are fixedly connected.

3. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting according to claim 1, feature Be: the vertical equity slot (8) in step 2 is rectangular channel.

4. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting according to claim 1, feature Be: the ratio of the cement of the cement mortar in step 3) and sand is 1:0.5, and the ratio of water and cement is between 0.8 ~ 1.0.

5. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting according to claim 1, feature It is: in step 3), injected hole is opened up on Concrete Filled layer (3) and passes through injected hole to Concrete Filled layer (3) and original Interstitial site between lining cutting (1) injects cement mortar, and injected hole operating pressure is controlled between 0.3 ~ 0.5MPa.

6. a kind of method using embedding arch shotcrete composite structure Strengthening Tunnel lining cutting according to claim 1, feature Be: concrete ejection layer (4) in step 5) with a thickness of 8-12cm, first on the inside of former lining cutting (1) before concrete ejection It is rinsed.