阅读说明：本技术 一种暗挖隧道超浅埋下穿公路的承力结构及施工方法 (Bearing structure of underground tunnel ultra-shallow buried underpass highway and construction method ) 是由 郑长青 赵万强 汤印 喻渝 游芬 叶伦 陈勇 邓子军 朱志远 王英学 范雲鹤 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种暗挖隧道超浅埋下穿公路的承力结构及施工方法,承力结构包括支撑部件；支撑部件用于设置在隧道的两侧,隧道两侧的支撑部件之间设有横撑,横撑用于设置在隧道的上方；横撑的顶部覆盖有盖板。在隧道两侧的支撑部件能够保障隧道开挖时公路路基的稳定性,隧道两侧的支撑部件之间设有横撑,且盖板覆盖在横撑的顶部在保证承力结构强度的同时还可以减小盖板的挠度,并承受上部附加荷载,并且施工完毕后,横撑和盖板可以拆除重复利用,节约了成本,该承力结构不仅可以支撑上部车辆荷载,还可以起到围护作用,且由于隧道上部已经设有承力结构,下部隧道暗挖时可以减少超前支护的强度。(The invention discloses a bearing structure of an underground excavated tunnel ultra-shallow buried underpass road and a construction method, wherein the bearing structure comprises a support part; the supporting parts are arranged on two sides of the tunnel, and cross braces are arranged between the supporting parts on the two sides of the tunnel and are arranged above the tunnel; the top of the cross brace is covered with a cover plate. The support parts on the two sides of the tunnel can ensure the stability of a highway subgrade when the tunnel is excavated, the cross braces are arranged between the support parts on the two sides of the tunnel, the cover plates cover the tops of the cross braces, the deflection of the cover plates can be reduced while the strength of a bearing structure is ensured, and the additional load on the upper part is borne, after the construction is finished, the cross braces and the cover plates can be detached and reused, the cost is saved, the bearing structure can support the load of vehicles on the upper part and can play a role in enclosure, and because the bearing structure is arranged on the upper part of the tunnel, the strength of advance support can be reduced when the tunnel on the lower part is excavated.)

1. A load-bearing structure of an underground tunnel ultra-shallow buried underpass road is characterized by comprising a support part (1);

the supporting parts (1) are arranged on two sides of the tunnel (6), cross braces (5) are arranged between the supporting parts (1) on two sides of the tunnel (6), and the cross braces (5) are arranged above the tunnel (6);

the top of the cross brace (5) is covered with a cover plate (2).

2. The force-bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 1, wherein the support part (1) on each side of the tunnel (6) comprises at least two piles which are arranged at intervals along the length direction of the tunnel (6).

3. The force bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 2, wherein the cross braces (5) are arranged along the width direction of the tunnel (6), the number of the cross braces (5) is at least two, and at least two of the cross braces (5) are arranged at intervals along the length direction of the tunnel (6).

4. The load-bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 3, wherein a surrounding purlin (3) is arranged between the cross support (5) and the corresponding pile body, the surrounding purlin (3) comprises I-steel, and connecting batten plates are arranged at two ends of the I-steel.

5. The force-bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 4, wherein the surrounding purlin (3) is respectively connected with the corresponding cross brace (5) and the corresponding pile body through a connecting device (4).

6. The force-bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 5, wherein the connecting device (4) comprises L-shaped angle steel and a fastener, and the L-shaped angle steel is connected with the fastener.

7. The force-bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to claim 6, wherein the upper surface of the surrounding purlin (3) is flush with the upper surface of the pile body, and the upper surface of the surrounding purlin (3) is flush with the upper surface of the cross brace (5).

8. The bearing structure of the underground excavated tunnel ultra-shallow buried underpass road according to any one of claims 1-7, wherein two ends of the cover plate (2) respectively extend out of the corresponding supporting parts (1).

9. A construction method of a bearing structure of an underground tunnel ultra-shallow buried undersea road, which is used for constructing the bearing structure of the underground tunnel ultra-shallow buried undersea road of claim 8, and comprises the following steps:

s1: arranging the pile bodies on two sides of the tunnel (6) by adopting the SMW method;

s2: constructing the enclosing purlin (3) on the inner sides of the pile bodies on the two sides of the tunnel (6);

s3: constructing the transverse support (5), wherein two ends of the transverse support (5) are connected with the surrounding purlin (3) through the connecting device (4);

s4: the cover plate (2) is arranged above the cross brace (5), two ends of the cover plate (2) extend out of the outer side of the pile body, and ground traffic is recovered after the cover plate (2) is completely constructed;

s5: excavating a lower tunnel (6) by adopting a step method;

s6: and after the tunnel (6) is constructed, the cover plate (2) and the cross braces (5) are removed, backfilling is carried out, and the highway subgrade and the pavement are constructed after the backfilling is finished.

Technical Field

The invention relates to the technical field of underground and tunnel engineering, in particular to a load-bearing structure of an underground excavated tunnel ultra-shallow buried underpass highway and a construction method.

Background

With the rapid development of economy in China, the construction of underground engineering has become a current hot problem. In underground engineering, the problem that a tunnel is close to the existing engineering is often unavoidable, and in order to solve the problem of soil disturbance and settlement caused by the fact that the tunnel penetrates through a highway subgrade, the operation safety of the existing highway is guaranteed, and higher requirements are required to be put forward on the design and construction of the tunnel. However, higher requirements often mean longer construction periods and higher management costs. The construction method of the existing tunnel shallow-buried underpass highway subgrade mainly comprises a shallow-buried underground excavation method, an open excavation method and a cover excavation method.

When the buried depth of the tunnel is smaller than the diameter of the tunnel, the tunnel is an ultra-shallow buried tunnel. Aiming at the condition of a tunnel passing through a highway under ultra-shallow burying, in the prior art, if a shallow burying and underground digging method is adopted for construction, the deformation of rocks around the ground surface and a tunnel is large, and the deformation is difficult to control. If a CD method, a CRD method, a double-side-wall pit guiding method and the like are adopted for tunnel excavation, although settlement can be reduced as much as possible, the working procedures of the construction method are relatively complex, the construction efficiency is very low due to the superposition of the working procedures and the working procedures, the operation of the section of road is greatly limited, great influence is caused on the surrounding public environment, and the quality of life of the surrounding public is influenced.

If the open cut method is adopted, a building envelope or a slope needs to be constructed, the construction risk is high, the cost is high, the economic benefit is poor, the whole construction period is long, traffic is loosened and the driving is interrupted during the construction period, the method has large influence on the order of public traffic, and the method is difficult to realize.

If the cover-excavation method is adopted, the construction process is complex, the method is more suitable for large-scale structures such as stations and the like, and when the tunnel is buried in an ultra-shallow manner and passes through a highway subgrade, large-scale machinery is difficult to operate due to limited fields, and the efficiency is low.

Disclosure of Invention

The invention aims to: aiming at the problems in the prior art, a load-bearing structure of an underground tunnel ultra-shallow buried underpass road and a construction method are provided.

In order to achieve the purpose, the invention adopts the technical scheme that:

a load-bearing structure of an underground tunnel ultra-shallow buried underpass road comprises a support part;

the supporting parts are arranged on two sides of the tunnel, and cross braces are arranged between the supporting parts on the two sides of the tunnel and are arranged above the tunnel;

the top of the cross brace is covered with a cover plate.

A bearing structure of a subsurface tunnel ultra-shallow buried underpass road can ensure the stability of a road bed when the tunnel is excavated by the structure, a cross brace is arranged between the supporting parts at the two sides of the tunnel, and the cover plate is covered on the top of the cross brace, thereby ensuring the strength of the bearing structure, reducing the deflection of the cover plate and bearing the additional load on the upper part, after the construction is finished, the cross brace and the cover plate can be disassembled for repeated use, thereby saving the cost, being economical and practical, the bearing structure not only can support the load of the upper vehicle, but also can play a role of enclosure, bear certain horizontal force when the lower tunnel is excavated and unloaded, ensure the smooth excavation of the lower tunnel, and in addition, because the upper part of the tunnel is provided with the bearing structure, the strength of the advance support can be reduced when the lower part of the tunnel is excavated, and the cost is further saved.

Preferably, the support members on each side of the tunnel comprise at least two piles, and the at least two piles are arranged at intervals along the length direction of the tunnel.

As a preferable scheme of the invention, the cross braces are arranged along the width direction of the tunnel, the number of the cross braces is at least two, and at least two cross braces are arranged at intervals along the length direction of the tunnel.

According to the preferable scheme, a surrounding purlin is arranged between the transverse support and the corresponding pile body and comprises I-shaped steel, and connecting batten plates are arranged at two ends of the I-shaped steel.

As a preferable scheme of the invention, the purlin is respectively connected with the corresponding wale and the pile body through a connecting device.

As a preferable scheme of the invention, the connecting device comprises L-shaped angle steel and a fastener, and the L-shaped angle steel is connected with the fastener. Through the structure, the connecting device adopts the form of L-shaped angle steel and a fastener, so that the cross brace can be conveniently detached.

As a preferable scheme of the invention, the upper surface of the purlin is flush with the upper surface of the pile body, and the upper surface of the purlin is flush with the upper surface of the cross brace. Through above-mentioned structure, this structure can maximum reduction of erection time, guarantees the intensity of stull simultaneously.

In a preferred embodiment of the present invention, both end portions of the cover plate extend outside the corresponding support members.

A construction method of a bearing structure of an underground excavated tunnel ultra-shallow buried underpass road is used for constructing the bearing structure of the underground excavated tunnel ultra-shallow buried underpass road, and comprises the following steps:

s1: arranging the pile bodies on two sides of the tunnel by adopting the SMW construction method;

s2: constructing the enclosing purlin on the inner sides of the pile bodies on the two sides of the tunnel;

s3: constructing the transverse strut, wherein two ends of the transverse strut are connected with the surrounding purlin through the connecting device;

s4: the cover plate is arranged above the cross brace, two ends of the cover plate extend out of the outer side of the pile body, and ground traffic is recovered after the cover plate is completely constructed;

s5: excavating a tunnel below by adopting a step method;

s6: and after the tunnel construction is finished, removing the cover plate and the cross braces, backfilling the soil, and constructing the highway subgrade and the pavement after backfilling is finished.

By the construction method, the pile body adopts the SMW construction method pile which is less limited in construction site and easy to construct, the construction efficiency is high, the construction period can be shortened to the maximum extent on the premise of ensuring the functionality and the safety of a bearing structure, and meanwhile, the pile body can be pulled out for recycling after the tunnel is run through, so that the investment is saved;

the construction method has the advantages that after the cover plate is completely constructed, road traffic can be recovered, and the lower tunnel can be constructed.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. a bearing structure of a subsurface tunnel ultra-shallow buried underpass road can ensure the stability of a road bed when the tunnel is excavated by the structure, a cross brace is arranged between the supporting parts at the two sides of the tunnel, and the cover plate is covered on the top of the cross brace, thereby ensuring the strength of the bearing structure, reducing the deflection of the cover plate and bearing the additional load on the upper part, after the construction is finished, the cross brace and the cover plate can be disassembled for repeated use, thereby saving the cost, being economical and practical, the bearing structure not only can support the load of the upper vehicle, but also can play a role of enclosure, bear certain horizontal force when the lower tunnel is excavated and unloaded, ensure the smooth excavation of the lower tunnel, and in addition, because the upper part of the tunnel is provided with the bearing structure, the strength of the advance support can be reduced when the lower part of the tunnel is excavated, and the cost is further saved.

2. By the construction method, the pile body adopts the SMW construction method pile which is less limited in construction site and easy to construct, the construction efficiency is high, the construction period can be shortened to the maximum extent on the premise of ensuring the functionality and the safety of a bearing structure, and meanwhile, the pile body can be pulled out for recycling after the tunnel is run through, so that the investment is saved;

the construction method has the advantages that after the cover plate is completely constructed, road traffic can be recovered, and the lower tunnel can be constructed.

Drawings

Fig. 1 is a schematic structural diagram of a bearing structure of an ultra-shallow buried underpass tunnel of an underground tunnel.

Fig. 2 is a plan layout view of a bearing structure of an ultra-shallow buried underpass road of an underground tunnel.

Fig. 3 is a schematic longitudinal section of a force-bearing structure of an ultra-shallow buried underpass tunnel according to the invention.

Fig. 4 is a schematic view of the connection between the purlin and the wale.

Fig. 5 is a cross-sectional view taken along a-a in fig. 4.

Icon: 1-a support member; 2-cover plate; 3-enclosing purlin; 4-a connecting means; 5-horizontal bracing; 6-tunnel.

Detailed Description

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

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

As shown in fig. 1 to 5, the embodiment provides a force-bearing structure of an underground excavated tunnel ultra-shallow buried underpass, which includes a support component 1, a cover plate 2, a surrounding purlin 3 and a cross brace 5;

the supporting parts 1 are used for being arranged on two sides of the tunnel 6, the supporting part 1 on each side of the tunnel 6 comprises at least two pile bodies, and the at least two pile bodies are arranged at intervals along the length direction of the tunnel 6;

specifically, the pile body can be a reinforced concrete pile or a steel sheet pile, the actual condition is selected according to the stratum property, the pile body in the application adopts a pile of an SMW construction method, the pile body of the pile of the SMW construction method is an H-shaped steel and cement mixing pile, whether the cement mixing pile is constructed or not is selected according to the actual condition, and the cement mixing pile is cancelled if the stratum is good and underground water does not develop;

the distance between the pile bodies along the axial direction of the tunnel 6 is 1m, the specification of the H-shaped steel is 300 multiplied by 300 (height multiplied by width), the inserting direction is vertical downward, the height direction is vertical to the trend of the tunnel, and the vertical depth is 0.5 times of the hole diameter below the base of the tunnel 6; the construction period can be shortened while the stability of the road bed close to the highway when the tunnel 6 is excavated is ensured, and the method is economical and practical;

the distance between the pile bodies on the two sides of the tunnel 6 and the two waists of the tunnel 6 is about 1 m;

the wales 5 are arranged between the supporting parts at two sides of the tunnel 6, the wales 5 are positioned above the tunnel 6, the wales 5 are arranged along the width direction of the tunnel 6, the number of the wales 5 is at least two, at least two wales 5 are arranged along the length direction of the tunnel 6 at intervals,

an enclosing purlin 3 is arranged between the cross brace 5 and the pile body, and specifically, the enclosing purlin 3 is positioned at the top of the pile body, is flush with the upper surface of the pile body and is arranged along the axis direction of the tunnel 6; the height of the purlin 3 along the direction vertical to the axis of the tunnel 6 is 0.474m, and the length along the axis of the tunnel 6 is the same as the arrangement range of the pile body, preferably 4 m;

the enclosing purlin 3 comprises I-shaped steel, connecting batten plates are arranged at two ends of the I-shaped steel, specifically, the enclosing purlin 3 is in a double-spliced I-shaped steel and batten plate mode, the type of the double-spliced I-shaped steel is I45b, the width of each batten plate is 12cm, and the thickness of each batten plate is 1.2 cm;

before constructing the enclosing purlin 3, soil layer strips on the inner side part of the pile foundation need to be excavated, and a construction space of the enclosing purlin 3 is reserved;

two sides of the enclosing purlin 3 are respectively connected with the cross brace 5 and the pile body through the connecting device 4, or two sides of the enclosing purlin 3 are respectively welded with the cross brace 5 and the pile body;

the connecting device 4 comprises an L-shaped angle steel and a fastener;

the enclosing purlin 3 is connected with the pile body on one side, one side of the L-shaped angle steel is connected with the enclosing purlin 3 through a fastener, and the other side of the L-shaped angle steel is connected with the pile body through a fastener;

the enclosing purlin 3 is connected with the cross brace 5 on one side, one side of the L-shaped angle steel is connected with the enclosing purlin 3 through a fastener, and the other side of the L-shaped angle steel is connected with the cross brace 5 through a fastener;

specifically, the fastener is a bolt;

specifically, soil layers are arranged at the positions of excavated cross struts 5, the cross struts 5 are arranged along the cross section direction of a tunnel 6, the left end and the right end of each cross strut 5 are connected with surrounding purlins 3 through connecting devices 4, the upper parts of the cross struts are flush with the upper surfaces of the surrounding purlins 3, the construction period can be shortened to the maximum extent, the strength of the cross struts 5 is ensured, the distance between the cross struts 5 along the axis direction of the tunnel 6 is 2m, and the distance can be adjusted properly according to the stratum condition;

the cross brace 5 adopts H-shaped steel, and the specification of the H-shaped steel is 200 multiplied by 200 (height multiplied by width);

the cover plate 2 is arranged at the top of the cross brace 5, two end parts of the cover plate 2 respectively extend out of the outer side of the pile body, and specifically, the upper surface of the cover plate 2 is parallel to the upper surface of the cross brace 5 and is a steel plate with the thickness of 1.8 cm; on the premise of ensuring the integrity of a bearing structure, the construction period can be greatly shortened, and the construction efficiency is improved;

the cover plates 2 are spliced in sections, and the length of each section along the direction of the tunnel 6 is 4 m; the width of the cover plate 2 slightly exceeds the pile bodies on both sides, and is preferably 50 cm.

The embodiment also provides a construction method of the bearing structure of the underground excavated tunnel ultra-shallow buried underpass road, which comprises the following steps:

s1: arranging pile bodies on two sides of the tunnel 6 by adopting the SMW method;

specifically, before the step S1, performing measurement lofting at the junction between the lower tunnel 6 and the existing highway above, and performing pile position calibration according to the arrangement mode (row arrangement) of pile foundations, the adjacent interval requirements, the size and the like;

the method comprises the following steps of (1) adopting steel sheet piles of an SMW (soil mixing wall) construction method, selecting whether to construct cement mixing piles according to actual conditions, cancelling the cement mixing piles if the stratum is good and underground water is not developed, wherein the distance between pile bodies along the axis direction of a tunnel 6 is 1m, the specification of H-shaped steel is 300 multiplied by 300 (height multiplied by width), the inserting direction is vertically downward, the height direction is vertical to the trend of the tunnel 6, and the vertical depth is 0.5 times of the hole diameter below the base of the tunnel 6;

s2: constructing enclosing purlins 3 on the inner sides of the pile bodies on the two sides of the tunnel 6;

specifically, before constructing the enclosing purlin 3, soil layer strips on the inner side part of a pile foundation need to be excavated, and a construction space of the enclosing purlin 3 is reserved; the surrounding purlin 3 is made of H-shaped steel; the enclosing purlin 3 is positioned at the top of the pile body and is flush with the upper surface of the pile body, the height of the enclosing purlin 3 in the direction vertical to the axis of the tunnel is 0.474m, and the length of the enclosing purlin in the direction of the axis of the tunnel 6 is the same as the arrangement range of the pile body, preferably 4 m; the purlin 3 adopts a double-spliced I-steel and batten plate type, the double-spliced I-steel type is I45b, the batten plate is 12cm in width and 1.2cm in thickness; the surrounding purlin 3 is connected with the steel sheet pile 1 through a connecting device 2; the connecting device 2 is connected by bolts or welded;

s3: constructing a transverse strut 5, wherein two ends of the transverse strut 5 are connected with the surrounding purlin 3 through a connecting device 4;

specifically, soil layers of strips at the positions of cross braces 5 are excavated, the cross braces 5 are constructed, the cross braces 5 are made of H-shaped steel, the specification of the H-shaped steel is 200 multiplied by 200 (height multiplied by width), the left end and the right end of each cross brace 5 are connected with an enclosing purlin 3 through connecting devices 4, the upper portions of the cross braces are flush with the upper surface of the enclosing purlin 3, each connecting device 4 is composed of L-shaped angle steel and bolts, the distance between the cross braces 5 along the axis direction of a tunnel 6 is 2m, and the distance can be adjusted according to stratum conditions in actual construction;

s4: a cover plate 2 is arranged above the cross brace 5, two ends of the cover plate 2 extend out of the outer side of the pile body, and ground traffic is recovered after the cover plate 2 is completely constructed;

specifically, a cover plate 2 is arranged above a cross brace 5, the cover plate 2 is a steel plate with the thickness of 1.8cm, the upper surface of the cover plate is parallel to the upper surface of the cross brace 5, the left end and the right end of the cover plate exceed the outer side of a pile body by 50cm, the cover plate 2 is assembled in sections, the length of each section is 4m along the axial direction of a tunnel, and ground traffic is recovered after the cover plate 2 is completely constructed;

s5: excavating a lower tunnel 6 by a step method;

specifically, a lower tunnel 6 is excavated by a step method, and simultaneously, the lining strength of the tunnel 6 can meet the requirement of the load of the upper highway, so that the upper enclosing structure and the steel plate can bear the additional load of the highway independently after being dismantled;

s6: after the tunnel 6 is constructed, the cover plate 2 and the cross braces 5 are removed, backfilling is carried out, and the highway subgrade and the pavement are constructed after the backfilling is finished;

specifically, after the construction of the tunnel 6 is completed, the cover plate 2 and the cross braces 5 are removed, backfilling is carried out, H-shaped steel in a pile body can be pulled out if necessary, cement mortar is backfilled in pile holes, and the construction is carried out to form a highway subgrade and a road surface after backfilling is completed.

The bearing structure of the underground excavated tunnel ultra-shallow buried underpass road and the construction method provided by the embodiment have the beneficial effects that:

the supporting parts 1 on the two sides of the tunnel 6 can ensure the stability of a highway subgrade when the tunnel 6 is excavated, the cross braces 5 are arranged between the supporting parts 1 on the two sides of the tunnel 6, the cover plate 2 covers the top of the cross braces 5, the deflection of the cover plate 2 can be reduced while the strength of a bearing structure is ensured, and the additional load on the upper part is borne, and after the construction is finished, the cross braces 5 and the cover plate 2 can be disassembled and reused, so that the cost is saved, the bearing structure is economical and practical, not only can support the load of vehicles on the upper part, but also can play a role of enclosure, when the lower tunnel 6 is excavated and unloaded, a certain horizontal force is borne, so that the smooth excavation of the lower tunnel 6 is ensured, in addition, because the bearing structure is arranged on the upper part of the tunnel 6, the strength of advanced support can be reduced when the;

the pile body adopts the SMW construction method pile which has small limitation on construction site and is easy to construct, the construction efficiency is high, the construction period can be shortened to the maximum extent on the premise of ensuring the functionality and the safety of a bearing structure, and meanwhile, the pile body can be pulled out for recycling after the tunnel 6 is communicated, so that the investment is saved;

according to the construction method, after the cover plate 2 is completely constructed, road traffic can be recovered, the lower tunnel 6 can be constructed, the construction period is short, the construction safety and the construction efficiency of the lower tunnel 6 can be guaranteed on the premise that the construction period is shortened to the maximum extent, and meanwhile, the negative influence of the structure construction on public life is minimized.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.