阅读说明：本技术 一种新建盾构隧道超临近超浅埋上跨既有隧道的施工防护体系及施工方法 (Construction protection system and construction method for newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel ) 是由 陆跃 罗文俊 刘俊 罗如平 江学辉 黄大维 于 2021-08-28 设计创作，主要内容包括：本发明公开了一种新建盾构隧道超临近超浅埋上跨既有隧道的施工防护体系及施工方法,包括以下步骤：根据位于新建盾构隧道下方既有隧道的使用要求以及现场土质的实际情况,设计竖向及水平方向MJS注浆加固体,在新建盾构超临近上穿既有隧道交叉处,沿着新建上穿隧道方向布置围护桩工作竖井,沿着新建上穿隧道方向采用管幕机推进,形成管幕,开挖土方至新建上穿隧道上方的抗浮板设计位置处,在既有隧道MJS注浆加固体两侧进行全套管灌注抗拔桩施工,灌注抗拔桩顶位于新建上穿隧道上方的抗浮板位置处,在新建上穿隧道上方设计位置处进行抗浮板施工,使抗浮板与灌注桩形成整体,实现上穿隧道及临近既有隧道的安全稳定性的目的。(The invention discloses a construction protection system and a construction method for a newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel, which comprises the following steps: according to the use requirements of an existing tunnel below a newly-built shield tunnel and the actual situation of field soil texture, designing a vertical and horizontal MJS grouting reinforcement body, penetrating the intersection of the existing tunnel on the lower part of the newly-built shield tunnel, arranging a fender pile working vertical shaft along the direction of the newly-built upper tunnel, pushing by a curtain machine along the direction of the newly-built upper tunnel to form a curtain, excavating earth to the design position of an anti-floating plate above the newly-built upper tunnel, carrying out full-casing grouting uplift pile construction on two sides of the existing tunnel MJS grouting reinforcement body, positioning the top of a grouting uplift pile at the position of the anti-floating plate above the newly-built upper tunnel, carrying out anti-floating plate construction at the design position above the newly-built upper tunnel, integrating the anti-floating plate and the grouting pile, and achieving the purpose of safety and stability of the upper tunnel and the adjacent existing tunnel.)

1. A construction method of a construction protection system for a newly-built shield tunnel to be super-close to super-shallow buried and over-span an existing tunnel is characterized by comprising the following steps: the method comprises the following steps:

a. designing a vertical and horizontal MJS grouting reinforcement body according to the use requirements of the existing tunnel below the newly-built shield tunnel and the actual situation of the field soil texture;

b. arranging a fender post working vertical shaft along the direction of a newly built upper tunnel at the crossing of the newly built shield over-close upper tunnel;

c. pushing by using a pipe curtain machine along the direction of the newly-built upper tunneling channel to form a pipe curtain, wherein the design of the pipe curtain is related to the use requirements of soil quality, the existing tunnel and the upper tunneling channel;

d. excavating earthwork to the design position of an anti-floating plate above the newly built upper tunnel;

e. the construction of the full-casing cast-in-place uplift pile is carried out on two sides of the existing tunnel MJS grouting reinforcement body, the top of the cast-in-place uplift pile is located at the position of an anti-floating plate above a newly-built upper tunnel, and the design of the cast-in-place uplift pile is related to parameters such as the thickness of soil covering of the upper tunnel, the soil quality and the anti-floating requirement;

f. and (3) performing anti-floating plate construction at a design position above the newly-built upper tunnel channel to enable the anti-floating plate and the cast-in-place pile to form a whole, wherein the design of the anti-floating plate is related to parameters such as the thickness of the upper tunnel channel covering soil, anti-floating requirements, soil quality and the like.

2. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and e, adopting uplift piles which are all long piles or adopting uplift piles which are combined in a long-short mode and are arranged at intervals.

3. The construction method of the construction protection system of the newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel according to claim 2, characterized in that: and e, fixedly connecting the tops of the uplift piles with the uplift plates, wherein the uplift piles are multiple in number, and the uplift piles are uniformly arranged on two sides of the uplift plates.

4. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and c, jacking the pipe curtain in a spiral unearthed jacking pipe mode to reduce the influence of the jacking construction process of the pipe curtain on the existing tunnel, forming a closed rigid isolation ring by the pipe curtain and reducing the influence of floating of the existing tunnel caused by shield tunneling construction of a newly-built tunnel.

5. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and d, the number of the working vertical shafts in the step b is two, and the working vertical shafts are respectively and fixedly connected with two ends of the pipe curtain.

6. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and (b) the grouting reinforcement bodies in the step (a) are positioned at the two sides and the top of the existing tunnel to form a gate-type reinforcement body, so that the influence of the construction of the cast-in-place uplift pile and the excavation of the upper tunnel on the existing tunnel is reduced, and the construction grouting liquid has no pollution to underground water.

7. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and f, arranging an anti-floating plate and a poured anti-floating pile protection system above the crossing range of the newly-built upper tunnel and the existing tunnel, wherein the anti-floating plate and the anti-floating pile protection system meet the uplift control value of the whole anti-floating of the superposed tunnel and the shield tunneling process for the shield top earthing.

8. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and c, adopting reinforced cement mixed soil for the pipe curtain in the step c.

9. The construction method of the construction protection system for the newly-built shield tunnel to exceed the adjacent ultra-shallow buried upper-span existing tunnel according to claim 1, characterized in that: and c, the pipe curtain in the step c and the reinforcing body in the step a are integrated through a connecting part, and the uplift pile in the step e and the working shaft in the step b are integrated through a connecting part.

10. The application provides a construction protection system for a newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel, which is characterized in that the construction protection system is obtained by construction according to the construction method for the newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of underground engineering, in particular to a construction protection system and a construction method for a newly-built shield tunnel super-close ultra-shallow buried upper-span existing tunnel.

Background

In recent years, with the large-scale construction of urban rail transit in China, the development and construction of urban underground engineering are developed rapidly, more and more super-adjacent shallow-soil-covered tunnel engineering are developed, and as long as 2020, the urban rail transit mileage in China approaches 8000km, wherein the subway mileage breaks through 6300 km. With the continuous encryption of urban rail transit road networks, the situation that new lines and established lines are subjected to three-dimensional crossing is increasing, and therefore a plurality of projects that new shield tunnels penetrate through existing operating tunnels are generated. By taking the Hangzhou region as an example, the number of the tunnel projects for the shield to pass through the subway reaches 62 by 2020, and 22 tunnel projects account for 35 percent. The newly-built shield penetrates the existing operation tunnel in the shallow soil covering layer, so that the phenomena of deformation of the soil layer and floating of the shield tunnel are inevitably caused, the deformation of the road surface and the stability of the shield construction are possibly greatly influenced, and the driving safety is even endangered. At present, when underground structures such as existing tunnels or channels exist under the geological condition of shallow soil covering, a stratum freezing method is generally adopted to reinforce the existing tunnels and has the following characteristics: the method is suitable for fine sand layers and clay silt, and the frozen soil has high strength and is uniform; the method has the advantages of complex equipment, difficult construction, long construction period, small reinforcing range, traffic influence caused by the phenomenon of melting and sinking in the later period and higher cost.

Under the geological condition of shallow earth covering and weak soil, particularly when a newly-built upper-penetrating tunnel is beyond the adjacent existing tunnel, in order to ensure the construction safety and stability of the upper-penetrating shield tunnel and the existing tunnel, a new more reliable and feasible construction method needs to be provided.

In view of the above, the invention provides a construction protection system and a construction method for a newly-built shield tunnel to be buried in an ultra-near ultra-shallow mode and to span an existing tunnel, so as to ensure the stability of the tunnel to be penetrated and the existing tunnel.

Compared with the prior patent, the invention has the characteristics of simple and convenient construction, good effect, wide application range and the like, so that a construction protection system and a construction method for a newly-built shield tunnel to be over-near ultra-shallow buried and over-span the existing tunnel are needed.

Disclosure of Invention

The invention aims to provide a construction protection system and a construction method for a newly-built shield tunnel to be buried beyond the near range and ultra-shallow and to span an existing tunnel, and solves the problems mentioned in the technical background. In order to achieve the purpose, the invention provides the following technical scheme: a construction protection system and a construction method for a newly-built shield tunnel to be super-close to super-shallow buried and overpass an existing tunnel comprise the following steps:

a. designing a vertical and horizontal MJS grouting reinforcement body according to the use requirements of the existing tunnel below the newly-built shield tunnel and the actual situation of the field soil texture;

b. arranging a fender post working vertical shaft along the direction of a newly built upper tunnel at the crossing of the newly built shield over-close upper tunnel;

c. and (4) pushing by using a tube curtain machine along the direction of the newly-built upper tunnel channel to form a tube curtain. The design of the pipe curtain is related to the use requirements of soil quality, an existing tunnel and an upper tunnel channel;

d. excavating earthwork to the design position of an anti-floating plate above the newly built upper tunnel;

e. the construction of the full-casing cast-in-place uplift pile is carried out on two sides of the existing tunnel MJS grouting reinforcement body, the top of the cast-in-place uplift pile is located at the position of an anti-floating plate above a newly-built upper tunnel, and the design of the cast-in-place uplift pile is related to parameters such as the thickness of soil covering of the upper tunnel, the soil quality and the anti-floating requirement;

f. and (3) performing anti-floating plate construction at a design position above the newly-built upper tunnel channel to enable the anti-floating plate and the cast-in-place pile to form a whole, wherein the design of the anti-floating plate is related to parameters such as the thickness of the upper tunnel channel covering soil, anti-floating requirements, soil quality and the like.

Preferably, the uplift piles in the step e can be uplift piles arranged by long piles or uplift piles arranged by long and short combination at intervals.

Preferably, the top of each uplift pile in the step e is fixedly connected with the uplift plate, the number of the uplift piles is multiple, and the uplift piles are uniformly arranged on two sides of the uplift plate.

Preferably, in the step c, the pipe curtain is jacked in a spiral unearthed pipe jacking mode so as to reduce the influence of the pipe curtain jacking construction process on the existing tunnel, the pipe curtain forms a closed rigid isolation ring, and the influence of floating of the existing tunnel caused by shield tunneling construction of a tunnel on a newly built tunnel is reduced.

Preferably, the number of the working shafts in the step b is two, and the working shafts are respectively fixedly connected with two ends of the pipe curtain.

Preferably, the grouting reinforcement bodies in the step a are positioned at two sides and the top of the existing tunnel to form a portal reinforcement body, so that the influence of the construction of the cast-in-place uplift pile and the excavation of the upper tunnel on the existing tunnel is reduced, and the construction grouting liquid does not pollute the underground water.

Preferably, an anti-floating plate and a poured anti-floating pile protection system are arranged above the crossing range of the newly-built upper tunnel and the existing tunnel in the step f, and the anti-floating plate and the anti-floating pile protection system meet the uplift control value of the whole anti-floating of the superposed tunnel and the uplift control value of the shield tunneling process on the shield top soil.

Preferably, the pipe curtain in the step c is made of reinforced cement mixed soil.

Preferably, the pipe curtain in the step c and the reinforcing body in the step a are integrated through a connecting part, and the uplift pile in the step e and the working shaft in the step b are integrated through a connecting part.

Preferably, the new shield tunnel according to any one of claims 1 to 9 is constructed by the construction protection system and the construction method of the super-close ultra-shallow buried overpass existing tunnel.

In conclusion, the invention has the following beneficial effects:

the invention relates to a construction protection system and a construction method for a newly-built shield tunnel super-close super-shallow buried upper-span existing tunnel, which form a new protection system and a construction method through portal MJS grouting reinforcement bodies, pipe curtains, pouring uplift piles and anti-floating plates.

Drawings

FIG. 1 is a schematic perspective view of an upper tunnel, an existing tunnel and long and short piles according to the present invention;

fig. 2 is a schematic perspective view of an upper tunnel, an existing tunnel and a long pile according to the present invention.

In the figure: 1. a working shaft; 2. passing a tunnel upwards; 3. an existing tunnel; 4. a pipe curtain; 5. reinforcing the body; 6. long piles; 7. an anti-floating plate; 8. shallow earthing; 10. and (5) short piles.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, in this embodiment, a combined support construction method of an MJS grouting portal reinforcement body 5, a pipe curtain 4, a full set of cast-in-place piles (6, 10) and an anti-floating plate 7 is adopted to realize the safety and stability of an upper tunnel 2 and an existing tunnel 3, and the specific steps are as follows:

a. according to the use requirement of an existing tunnel below a newly-built shield tunnel and the actual situation of field soil texture, a vertical and horizontal MJS grouting reinforcement body 5 is designed, according to the deformation and anti-floating requirement of the existing tunnel 3 and the actual situation of the field soil texture, MJS grouting reinforcement is carried out on two sides and the horizontal direction of the existing tunnel 3 to form a gate reinforcement body 5, the effect of protecting two sides and the top of the existing tunnel 3 is achieved, the newly-built existing tunnel is prevented from influencing the existing tunnel, the depth, the width, the length and the grouting strength of the gate reinforcement body 5 need to be calculated and determined, and the selected construction grouting liquid has no pollution to underground water;

b. arranging fender post working vertical shafts 1 along the direction of a newly-built upper tunnel passage 2 at the crossing position of the newly-built shield over close to the upper tunnel, wherein the number of the working vertical shafts 1 is two, the two working vertical shafts are respectively positioned at two ends of the newly-built upper tunnel passage 2 and arranged at two sides of an existing tunnel 3, the working vertical shafts 1 are formed by fender posts, and the design of the fender posts is according to relevant parameters such as soil quality, newly-built upper tunnel, use requirements of the existing tunnel and the like;

c. and (3) pushing by using a tube curtain machine along the direction of the newly-built upper tunnel channel 2 to form a tube curtain 4. The design of the pipe curtain 4 is related to the use requirements of soil quality, the existing tunnel 3 and the upper-penetrating tunnel, and the pipe curtain 4 is constructed to enable the pipe curtain 4 and the working vertical shaft 1 with two ends arranged to form a whole. The pipe curtain machine (spiral unearthed pipe jacking mode) is adopted to jack the pipe curtain 4 with the relevant diameter along the direction of the new upper tunnel 2, so that the influence of jacking construction of the pipe curtain 4 on the existing tunnel 3 is reduced, the pipe curtain 4 forms a closed rigid isolation ring, and the influence of the new upper tunnel tunneling process on the existing tunnel 3 is reduced. The pipe curtain 4 is made of reinforced cement mixed soil, and the design of the pipe curtain 4 is calculated and determined according to relevant parameters such as soil quality, newly-built upper-penetrating tunnel 2, use requirements of existing tunnel 3 and the like.

d. Excavating earthwork 8 to a design position above the newly-built upper tunnel 2 and leveling the field;

e. the construction of a full-casing full-slewing drilling machine is carried out on two sides of an existing tunnel 3 vertical MJS grouting reinforcement body 5 to form a poured uplift pile, the top of the poured uplift pile is located at the position of an anti-floating plate 7 above a newly-built tunnel, the poured uplift pile and the anti-floating plate 7 are integrated, the anti-floating plate 7 of the uplift pile plays a stretching role, the anti-floating treatment of the anti-floating plate 7 on the tunnel is enhanced, the design of the poured uplift pile is related to parameters such as the soil covering thickness, the soil quality and the anti-floating requirement of an upper tunnel 2, the uplift pile can be arranged by adopting equal-length piles 6 (shown in figure 2), and the long piles 6 and the short piles 10 can be arranged at intervals (shown in figure 1). In order to save the construction cost, the invention preferentially recommends a long and short combination interval setting scheme, and the specific arrangement parameters of the scheme are calculated according to the actual working condition and the anti-floating requirement. The construction of the cast-in-place uplift pile needs to ensure that a sleeve needs to be drilled in advance in the drilling process, and mud and sand gushing in the sleeve is prevented. The top of the poured uplift pile is positioned at a design position above the newly-built upper tunneling channel 2, and the design of the poured uplift pile is based on relevant parameters such as the thickness of the covering soil, the soil quality and the anti-floating requirement of the newly-built upper tunneling channel;

f. and (3) constructing an anti-floating plate 7 at a design position above the newly-built upper tunnel, so that the anti-floating plate 7 and the cast-in-place pile form a whole, wherein the design of the anti-floating plate 7 is related to the parameters of the upper tunnel, such as the soil covering thickness, the anti-floating requirement, the soil quality and the like, and the anti-floating plate needs to meet the uplift control value of the whole anti-floating of the superposed tunnel and the soil covering on the top of the shield in the shield tunneling process.

The pipe curtain in the step c and the reinforcing body in the step a are integrated through a connecting part, the uplift pile in the step e and the working vertical shaft in the step b are integrated through a connecting part, the pipe curtain and the reinforcing body are fixedly connected together through the connecting part, the uplift pile and the working vertical shaft are fixedly connected together, and the reinforcing body 5, the pipe curtain 4, the uplift pile and the anti-floating plate 7 are connected together to form a whole because the working vertical shaft and the pipe curtain are fixedly connected together, so that the effect of better protection effect of the invention is realized

The MJS grouting reinforcement has the functions of protecting two sides and the top of an existing tunnel 3, preventing a newly-built existing upper tunnel 2 from influencing the existing tunnel 3 and a pipe curtain 4, playing the effect of isolating the upper tunnel 2 from the existing tunnel 3 again, having the effect of reinforcing and protecting the existing tunnel 3, connecting an uplift pile and an anti-floating plate 7 together to realize the effect of resisting the whole floating of the upper tunnel 2 and the existing tunnel 3, combining the MJS grouting reinforcement body 5, the pipe curtain 4, the uplift pile and the anti-floating plate 7 into a new reinforcement system, greatly reducing the uplift value of shallow earth covering on the top of a shield in the shield tunneling process, meeting the safety and risk control of the tunnel and the existing tunnel, reducing the harm brought by the uplift pile, and realizing the purposes of safety and stability of the upper tunnel and the adjacent existing tunnel, wherein the construction method is divided into two parts, the first part is used for ensuring that the newly-built tunnel does not influence the stability of the existing tunnel, firstly, adopting vertical MJS grouting to reinforce soil on two sides of an existing tunnel, secondly adopting horizontal MJS grouting to reinforce the soil above the existing tunnel, and finally adopting a pipe curtain method to form a rigid isolation layer on the upper part of the existing tunnel so as to ensure that the stability of the existing tunnel 3 is not influenced by newly-built tunnel 2; the second part is to ensure the safety and stability of the newly built upper tunnel 2 in a shallow soil layer (the depth is less than 6 m), firstly, the site is leveled and the earthwork is excavated to the anti-floating plate 7 above the newly built upper tunnel 2, secondly, the construction is carried out on the two sides of the MJS grouting portal reinforcement body of the existing tunnel 3 at the lower part by adopting a full-casing rotary excavating drilling and filling uplift piles, the filling uplift piles can be arranged by adopting equal-length piles 6 or long-short combined piles according to the design, and finally, the construction of the anti-floating plate 7 is carried out above the newly built upper tunnel (the anti-floating plate 7 and the uplift piles are integrally formed), thereby ensuring the safety and stability of the newly built upper tunnel. The invention can meet the overall anti-floating stability of the newly built upper tunnel, prevent the influence of the newly built upper tunnel on the existing tunnel and reduce the harm brought by the influence.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.