CN211144521U - Advance support structure assembled by corrugated steel pipe sheets - Google Patents

Abstract

The utility model relates to an adopt advance support structure that corrugated steel pipe piece was assembled for guarantee the stability of tunnel engineering excavation working face, this structure includes along the fixed a plurality of corrugated steel of the vertical mutual overlap joint in tunnel assemble the module and pack the slip casting body in the space between module and tunnel country rock through pouring into, corrugated steel assemble the module by connect at the hoop joint and through vertical joint assemble fashioned multi-disc corrugated steel pipe piece and constitute at vertical rigid coupling through the hoop. Compared with the prior art, the utility model has the advantages of modular assembly and high construction efficiency; the structure has high strength and can be used as a primary supporting structure; the intelligent and automatic construction is facilitated.

Description

Advance support structure assembled by corrugated steel pipe sheets

Technical Field

The utility model belongs to the technical field of the advance support in tunnel and specifically relates to an advance support structure who adopts corrugated steel pipe piece to assemble is related to.

Background

The unstable collapse phenomenon is easy to occur when the tunnel is excavated in the geological environment of the weak surrounding rock, so that the advance support needs to be made by taking the tunnel excavation contour line as the reference before construction, the stress state of the surrounding rock can be improved by the advance support method, the surrounding rock is reinforced, and the convergence deformation of the tunnel and the disturbance to the surrounding environment are controlled. The advance support has become the key measure of tunnel crossing weak broken country rock, and its design is very important.

The common advance support mode of the tunnel at present mainly comprises a pipe shed method, advance small conduit grouting, advance anchor rods and the like. The pipe shed method is characterized in that holes are pre-drilled and thick-wall steel pipes with large inertia moment are installed on a lining arch ring hidden submerged arc line of an underground tunnel or structural engineering to be excavated to play a role of temporary advanced support and prevent soil layer collapse and ground surface subsidence so as to ensure safe operation of tunneling and subsequent support processes; the advanced small conduit grouting is used for reinforcing the loose rock stratum in the weak and broken rock stratum through small conduit grouting, and the stability of the loose weak surrounding rock is enhanced after grouting, so that the surrounding rock is stabilized within the time of completing excavation and primary support; the advanced anchor rod is driven into a stable rock layer in front of tunneling, so that surrounding rock is effectively restrained from loosening and collapsing within a certain time after blasting. The forepoling modes can play a role in reinforcing surrounding rocks, but have some defects. When the pipe-shed method is used for construction, a sufficient number of rod piece structures capable of diffusing or transferring surrounding rock pressure are required to form a shed, namely, a sufficient number of steel pipes are required to be driven in and are generally adopted at a tunnel opening; the advanced small conduit grouting and the advanced anchor rod are required to strictly control the drilling angle of the small conduit and the anchor rod under the condition of ensuring enough quantity, and the construction is complex. The three can not realize the assembly construction, the construction efficiency is low, and the period is long.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a forepoling structure who adopts corrugated steel pipe piece to assemble in order to overcome the defect that above-mentioned prior art exists.

The purpose of the utility model can be realized through the following technical scheme:

the utility model provides an adopt advance support structure that corrugated steel pipe piece was assembled for guarantee the stability of tunnel engineering excavation working face, this structure includes along the module is assembled to a plurality of corrugated steel that the vertical mutual overlap joint of tunnel is fixed and packs the slip casting body in the space between module and tunnel country rock through pouring into, corrugated steel assemble the module by connect in the hoop joint and connect in vertical rigid coupling and assemble fashioned multi-disc corrugated steel pipe piece through the hoop and constitute.

The central angle range of the corrugated steel assembly module in the circumferential surrounding rock support is 120-180 degrees, and the tunnel framing is comprehensively determined according to the advanced support range, the tunnel profile, the mechanical assembly capacity, the assembly environmental conditions and the like.

The corrugated steel pipe sheet is made of Q235 steel materials, under the supporting scene of a two-lane highway tunnel, the length and the width of each corrugated steel pipe sheet are determined according to the tunnel amplitude and each footage (grooving length), the length is 300-400 cm, the width is 150-160 cm, the special position is correspondingly changed according to the assembling environment condition, the wave distance, the wave height and the plate thickness of the corrugated steel need to be designed in consideration of factors such as construction load, transportation load and advanced supporting strength, the wave distance is 30-40 cm, the wave height is 10-15 cm, and the plate thickness is 8-10 mm.

The hoop connect be a prefabricated buckle, it is bent the shaping through the cubic by corrugated steel pipe sheet hoop tip, the buckle be located between adjacent crest and trough, its length is 0.5 times of half wavelength to at buckle department coating lubrication stagnant water thick liquid, in order to do benefit to assembling and realize effective stagnant water.

The longitudinal joint is in a flange joint form and comprises a steel plate with bolt holes and M20 bolts, wherein the steel plate is welded at the longitudinal end part of the corrugated steel pipe sheet, the M20 bolts are connected with each other through the bolt holes, the longitudinal length of the longitudinal joint is the same as that of the corrugated steel pipe sheet, the thickness of the steel plate is close to that of the corrugated steel pipe sheet, the height of the steel plate is slightly larger than the wave height, and steel is matched with the corrugated steel and is made of Q235.

The steel plate is prefabricated according to the longitudinal end boundary of the corrugated steel pipe sheet, the shape of the steel plate is a rectangular surface at each annular joint, a trapezoidal surface is arranged at each corrugation, the bolt holes are formed in the trapezoidal surfaces, the number of the bolt holes is 3, and the bolt holes are arranged in the positions corresponding to the wave trough ranges of the corrugated steel in an equilateral triangle mode.

The hole opening shape of the bolt hole is a rectangle with two sides added with double semicircles, the long side of the rectangle is 2-3 times of a circle radius, and the hole opening directions of the bolt holes on the steel plate trapezoidal parts of the longitudinal joints of the adjacent corrugated steel pipes are mutually vertical.

The grouting body is formed by injecting through grouting holes formed in the corrugated steel pipe sheet, the proportion of cement mortar adopted by the grouting body is that cement and mortar are 3: 7, the grouting pressure adopted during grouting is 0.3-0.5 MPa, and the grouting speed is 30-60L/min.

Each corrugated steel pipe sheet is provided with a plurality of high-strength bolt holes side by side along the circumferential direction, and two longitudinally adjacent corrugated steel pipe sheets are fixedly connected with each other through M20 high-strength bolts.

A supporting method of a forepoling structure assembled by corrugated steel pipe sheets comprises the following steps:

1) grooving by adopting an arch frame type mechanical grooving machine along the outer arc contour line of the tunnel according to preset thickness, length and angle, wherein the thickness is 1.1-1.2 times of the wave height of the corrugated steel pipe sheet, the grooving length is 4-5 m, and the external insertion angle is 1-3 degrees, so that a grooving in the outer contour shape of the tunnel is formed;

2) after grooving is finished, placing the prefabricated corrugated steel pipe sheet in the grooving, extending an assembling section outwards, and completing assembling of a first ring of corrugated steel pipe sheets through a circumferential joint;

3) assembling the second ring of corrugated steel pipe sheets and the first ring of corrugated steel pipe sheets through the longitudinal joint and the annular joint;

4) after the two rings of corrugated steel pipe sheets are assembled, the assembled corrugated steel pipe sheets are pushed into the cutting grooves by an excavator and extend outwards for an assembling section, the step 3) is repeated, and the assembling of the corrugated steel pipe sheets is continued;

5) repeating the step 4) until the corrugated steel pipe sheets reach the innermost side of the cutting groove, welding a flat steel plate for plugging when the last ring of corrugated steel pipe sheets are prefabricated, grouting according to the reserved grouting holes by adopting a grouting pump, and plugging the grouting holes by adopting a plugging agent after grouting is finished to finish the first section of construction;

6) excavating the tunnel face to the innermost position of the corrugated steel pipe sheet, repeating the steps 1) -4) until the corrugated steel pipe sheet reaches the innermost side of the second section of cutting groove, reserving a row of bolt holes at the crest curved surface of the connecting position of the corrugated steel pipe sheet of the last construction section when the corrugated steel pipe sheet of the last ring of the construction section is prefabricated, performing on-site hole opening on the corrugated steel pipe sheet of the last construction section corresponding to the crest curved surface position, and connecting the front corrugated steel pipe sheet and the rear corrugated steel pipe sheet by adopting M20 high-strength bolts, wherein the lap joint length is 0.5M;

7) after longitudinal front and back lap joint is finished, grouting is carried out on the grouting holes by adopting a grouting pump, and plugging is finished by adopting a plugging agent to plug the grouting holes so as to finish the second section of construction;

8) and repeating the steps 6) to 7) until the construction is finished.

Compared with the prior art, the utility model has the advantages of it is following:

firstly, the support strength is high: the utility model discloses a corrugated steel pipe piece exist the ripple shape to increase corrugated steel's bending resistance moment of inertia, increased the intensity and the rigidity of structure, compare more than tens of times with ordinary steel sheet, its support intensity greatly increased.

Secondly, transportation simple to operate, the efficiency of construction is high: the corrugated steel pipe sheet adopts a form of a factory prefabricated plate, the pipe distribution sections and the plate distribution sheets are transported in a sleeve and stacking and bundling mode, the self weight is light, the transportation is convenient, the assembly construction is adopted on site, the assembly process is simple, the construction is rapid, the construction workload is reduced, the construction efficiency is greatly improved, and the construction period is shortened.

Thirdly, the structural continuity is good: the utility model discloses a advance support structure for the composite construction that corrugated steel pipe piece and slip casting combination formed, it is better for the continuity of pipe shed method construction structures, can regard as primary support structure or primary support's partly.

Fourthly, intelligent and automatic construction is facilitated to be realized: the utility model has the characteristics of the modularization construction, follow the automatic construction of shield segment and can realize the intellectuality and the automation of assembling in future.

Drawings

Fig. 1 is a schematic cross-sectional view of the structure of the present invention.

Fig. 2 is the vertical schematic diagram of the structure construction sequence of the utility model.

Fig. 3 is a schematic diagram of a prefabricated corrugated steel pipe sheet, wherein fig. 3a is a last ring corrugated steel pipe sheet of a first construction section, fig. 3b is a middle ring corrugated steel pipe sheet of each construction section, fig. 3c and fig. 3d are respectively a lap ring corrugated steel pipe sheet between two construction sections, wherein fig. 3c is a lap ring corrugated steel pipe sheet of a previous construction section, and fig. 3d is a lap ring corrugated steel pipe sheet of a next construction section.

Fig. 4 is a schematic view of circumferential connection of corrugated steel pipe sheets.

Fig. 5 is a schematic view of longitudinal connection of corrugated steel pipes, where (5a) is a schematic view of a longitudinal joint of adjacent corrugated steel pipes, (5b) is a schematic view of longitudinal connection of corrugated steel pipes by bolts, and (5c) is a schematic view of relative positions of openings of bolt holes when adjacent corrugated steel pipes are connected at a longitudinal connection point.

Fig. 6 is a schematic view of bolt holes in a flange.

Fig. 7 is a schematic diagram of the overlapping of corrugated steel pipes between construction sections, in which fig. 7a is a schematic diagram of the overlapping of longitudinally adjacent corrugated steel pipes, and fig. 7b is a partially enlarged view of the overlapping portion.

The notation in the figure is:

① is corrugated steel assembly module, ② is grouting body;

1-1, prefabricated corrugated steel plates, 1-2, circumferential joints, 1-3, longitudinal joints, 2-1, cement mortar, 2-2, grouting holes, 3, M20 bolts, 4, M20 bolt holes, 5, M20 high-strength bolt holes, 6, flange plates A and 7, flange plates B and 8, a tunnel face, 9 and M20 high-strength bolts;

i: construction first stage, II: and a second construction stage, III: i and II overlap joint sections.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The embodiments of the present invention are described below with specific examples, and those skilled in the art can easily understand the advantages and effects of the present invention from the disclosure in the specification. The present invention can also be implemented or applied by other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

It should be understood that the structures, ratios, sizes and the like shown in the drawings attached to the present specification are only used for matching with the contents disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limit conditions that the present invention can be implemented, so that the present invention has no technical essential meaning, and any modification of the structures, changes of the ratio relation or adjustment of the size should still fall within the scope that the technical contents disclosed in the present invention can cover without affecting the efficacy that the present invention can produce and the purpose that the present invention can achieve.

Examples

As shown in fig. 1, in the advance support structure assembled by corrugated steel pipe sheets in this embodiment, the composite structure composed of the corrugated steel pipe sheets and the grouting body fully exerts the characteristic of high support strength of the corrugated steel structure, and the corrugated steel and the surrounding rock form a continuous whole by means of grouting. Through the assembly construction, the construction efficiency is greatly improved, so that the surrounding rock deformation caused by tunnel excavation is controlled, and the stability of the excavation surface during tunnel excavation is ensured.

This composite construction mainly includes: corrugated steel assembles module 1 and slip casting 2.

The corrugated steel assembling module 1 is formed by assembling and connecting prefabricated corrugated steel pipe sheets 1-1 and longitudinal joints 1-3 through annular joints 1-2, the prefabricated corrugated steel pipe sheets 1-1 are jacked in a pre-formed cutting groove, the external insertion angle phi of the corrugated steel pipe sheets is 1-3 degrees, the footage (cutting groove length) is 4-5 m each time, the advance supporting range is A-B, ∠ AOB is 120-180 degrees, and the tunnel framing is comprehensively determined according to the advance supporting range, the tunnel profile, the mechanical assembling capacity, the assembling environmental conditions and the like.

As shown in fig. 3, the prefabricated corrugated steel pipe sheets 1-1 are made of Q235 steel, in this embodiment, for a two-lane highway tunnel, according to the tunnel framing and each footage (grooving length), etc., the length l1 of the first type corrugated steel pipe sheet is 350cm, the width b is 150cm, the length of the second type corrugated steel pipe sheet is the same as that of the first type, and the width b is 100 cm; the wave distance s is 38cm, the wave height h1 is 14cm, the plate thickness t1 is 9mm, and factors such as construction load, transportation load, advance support strength requirements and the like need to be considered during actual design.

The grouting body 2 is formed by injecting cement mortar 2-1 into a gap between the corrugated steel pipe sheet 1-1 and surrounding rock through the grouting hole 2-2, wherein the ratio of the cement to the mortar is 3: 7, the grouting pressure of the cement mortar is 0.5MPa, the grouting speed is 30-60L/min, the aperture of the grouting hole is 100mm, and the plugging agent is adopted to plug the grouting hole after grouting.

As shown in fig. 4, the circumferential joint 1-2 is in the form of a snap joint, the structural form of the snap joint is prefabricated in a factory, the corrugated steel plate is bent three times to form the snap joint on the basis of ensuring the continuity of corrugations at two sides of the joint, the snap joint is positioned between adjacent wave crests and wave troughs, and the length of the snap joint is about 0.5 times of half wavelength (namely 0.25 λ, λ is the wavelength). The joint is coated with lubricating water-stopping slurry in advance for stopping water, the slurry can initially play a role in reducing the friction resistance during jacking of the steel plates, and the water seepage path between the corrugated steel plates can be solidified when the slurry meets water after jacking is finished.

As shown in fig. 5, the longitudinal joints 1-3 are in the form of flange joints, and are composed of steel plates 6, 7 with bolt holes and bolts 3 welded at the longitudinal ends of corrugated steel pipe sheets; the steel plates 6 and 7 are prefabricated according to the longitudinal end boundary of the corrugated steel pipe sheet, the shape of the steel plates is rectangular at the annular joint of the corrugated steel, and the shape of the steel plates is trapezoidal at the corrugation position of the corrugated steel; the thickness t2 of the steel plate is 9mm (similar to the thickness t1 of the corrugated steel pipe sheet), the length l2 is the same as the length l1 of the corrugated steel pipe sheet, the height h2 is 16cm (slightly larger than the wave height h1), the steel material is matched with the corrugated steel, and Q235 steel is adopted; the connection is made using M20 bolts; the bolt holes in the flange plate are double semi-circles and rectangular bolt holes, wherein the radius (r) of the double semi-circles is 10-12 mm, and the long side of the rectangle is (2-3) r; within the corrugated steel trough, 3 holes are arranged in an equilateral triangular arrangement for each wavelength range.

As shown in fig. 6, there are two types of longitudinal joint steel plates: the flange A and the flange B are respectively positioned at two ends of the corrugated steel pipe sheet; the bolt holes in the flange A are vertical, the bolt holes in the corresponding positions in the flange B are horizontal, and the bolt holes in the corresponding positions of the flange A and the flange B are perpendicular to each other during assembly, so that the bolts in the assembly process have a certain moving range in the horizontal direction and the longitudinal direction, and certain construction errors are allowed to exist in the bolt holes.

In the embodiment, the advance support structure assembled by corrugated steel pipe sheets comprises the following construction steps:

s1 grooving along the contour line of tunnel outer arc by arch frame type mechanical pre-grooving machine according to preset thickness, length and angle, the thickness is 1.1-1.2 times of wave height h of corrugated steel pipe sheet, the grooving length is 4m, and the external angle is inserted

Taking 1-3 degrees to form a cutting groove in the shape of the outer contour of the tunnel;

s2, after grooving is completed, immediately placing a 1 st block of the corrugated steel pipe sheet 1-1 prefabricated in a factory into the grooving, extending a small section (about 0.2l for convenient assembly), and completing assembly of a first ring of corrugated steel pipe sheets through a circumferential joint 1-2;

s3, assembling the second ring of corrugated steel pipe sheets and the first ring of corrugated steel pipe sheets through the longitudinal joint 1-3 and the circumferential joint 1-2;

s4, after the two rings are assembled, the assembled corrugated steel pipe sheet is pushed into the cutting groove for a certain distance by an excavator (with a mechanical arm pushing forwards) and stretches a small section (about 0.2 l) outwards, the step 3 is repeated, and the assembly of the corrugated steel pipe sheet is continued;

s5, repeating the step 4 until the corrugated steel pipe sheet reaches the innermost side of the cutting groove, welding a flat steel plate for blocking when the last ring of corrugated steel pipe sheet is prefabricated, adopting a grouting pump for grouting according to the reserved grouting hole 2-2, and completing the first section of construction by adopting a plugging agent for plugging the grouting hole after grouting;

s6, excavating the tunnel face to the innermost position of the corrugated steel pipe sheet, and repeating the steps 1-4 until the corrugated steel pipe sheet reaches the innermost side of the second section of cutting groove. When the corrugated steel pipe sheet of the last ring of the construction section is prefabricated, a row of bolt holes with the aperture of 21mm are reserved at the crest curved surface of the connecting position of the corrugated steel pipe sheet of the last construction section; performing on-site hole opening on the position, corresponding to the crest curved surface, of the corrugated steel pipe sheet of the previous construction section, wherein the hole diameter is 21mm, connecting the front corrugated steel pipe sheet and the rear corrugated steel pipe sheet by using M20 high-strength bolts, and the lap joint length is 0.5M;

s7, grouting the grouting hole 2-2 by using a grouting pump after the front and back lap joint is finished, and plugging the grouting hole by using a plugging agent after the grouting is finished to finish the second section of construction;

s8, repeating the steps 6-7 until the construction is finished.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (9)

1. The utility model provides an adopt advance support structure that corrugated steel pipe piece was assembled for guarantee tunnel engineering excavation working face's stability, its characterized in that, this structure includes along the module (1) is assembled to a plurality of corrugated steel of tunnel vertical mutual overlap joint fixed and through pouring into the grout body (2) of filling in the space between module (1) is assembled to corrugated steel and tunnel country rock, corrugated steel assemble module (1) by assembling fashioned multi-disc corrugated steel pipe piece (1-1) through hoop joint (1-2) at hoop joint and through vertical joint (1-3) at vertical rigid coupling and constitute.

2. The forepoling structure assembled by corrugated steel pipe sheets as claimed in claim 1, wherein the central angle of the corrugated steel assembly module (1) in the circumferential surrounding rock supporting is 120-180 degrees.

3. The forepoling structure assembled by the corrugated steel pipe sheets as claimed in claim 1, wherein the corrugated steel pipe sheets (1-1) are made of Q235 steel materials, and under the supporting scene of a two-lane highway tunnel, each corrugated steel pipe sheet (1-1) is 300-400 cm in length, 150-160 cm in width, 30-40 cm in wave distance, 10-15 cm in wave height and 8-10 mm in plate thickness.

4. The forepoling structure assembled by corrugated steel pipe sheets as claimed in claim 1, wherein the circumferential joint (1-2) is a prefabricated buckle formed by bending the circumferential end of the corrugated steel pipe sheet (1-1) for three times, the buckle is located between adjacent wave crests and wave troughs, the length of the buckle is 0.5 times of half wavelength, and the buckle is coated with lubricating water-stopping slurry.

5. The forepoling structure assembled by corrugated steel pipe sheets as claimed in claim 1, wherein the longitudinal joints (1-3) are in the form of flange joints comprising steel plates with bolt holes welded to the longitudinal ends of the corrugated steel pipe sheets (1-1) and M20 bolts (3) for being connected with each other through the bolt holes, and have the same longitudinal length as the corrugated steel pipe sheets (1-1).

6. The forepoling structure assembled by corrugated steel pipe sheets according to claim 5, wherein the steel plate is prefabricated according to the longitudinal end boundary of the corrugated steel pipe sheet, the shape of the steel plate is a rectangular surface at each circumferential joint (1-2), the shape of the steel plate is a trapezoidal surface at each corrugation, the bolt holes are formed in the trapezoidal surface, the number of the bolt holes is 3, and the bolt holes are arranged in the positions corresponding to the wave trough ranges of the corrugated steel in an equilateral triangle manner.

7. The forepoling structure assembled by corrugated steel pipes as claimed in claim 6, wherein the holes of the bolt holes are in the shape of a rectangle with two sides added with double semi-circles, the long side of the rectangle is 2-3 times of a circle radius, and the hole directions of the bolt holes on the steel plate trapezoidal parts of the longitudinal joints (1-3) of the adjacent corrugated steel pipes (1-1) are perpendicular to each other.

8. The forepoling structure assembled by corrugated steel pipe sheets according to claim 1, wherein the grouting body (2) is injected and molded through grouting holes (2-2) formed in the corrugated steel pipe sheets (1-1).

9. The forepoling structure assembled by corrugated steel pipe sheets according to claim 1, wherein each corrugated steel pipe sheet (1-1) is provided with a plurality of high-strength bolt holes (5) in parallel along the circumferential direction, and two longitudinally adjacent corrugated steel pipe sheets (1-1) are fixedly connected with each other through M20 high-strength bolts (9).

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