Protection monitoring system for adjacent bridge in subway foundation pit excavation period

Abstract

The utility model discloses a protection monitoring system for an adjacent bridge in the excavation period of a subway foundation pit, and relates to the technical field of subway construction, the protection monitoring system comprises a protection structure and a monitoring device, the protection structure comprises a concrete isolation layer and a continuous wall, the bridge comprises a top beam, a plurality of bridge piles located underground and piers supported on the tops of the bridge piles, the top beam is supported on the piers, the concrete isolation layer is arranged between the bridge piles and the foundation pit, the side wall, close to the bridge, of the foundation pit is correspondingly provided with a continuous wall, and a grouting reinforcement layer is formed between the continuous wall and the concrete isolation layer; a plurality of first monitoring point positions are arranged on the bridge surface of the top beam at intervals in the length direction, and each pier is provided with a second monitoring point position; the monitoring device comprises a level gauge and an inclinometer. The influence of foundation pit excavation on the bridge pile can be effectively isolated through the protection structure, whether a bridge settles or inclines or not can be found in time through the monitoring equipment, and potential safety hazards are greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to subway construction technical field especially relates to a subway foundation pit excavation period to the protection monitoring system of adjacent bridge. BACKGROUND

[0002] With the rapid development of economy and technology and the continuous advance of urbanization of our country, the demand of our country city to subway is increasing. In the process of subway construction, subway foundation pit excavation can produce stress disturbance to adjacent bridge, cause bridge pile and pier to be easy to damage, influence long-term stability of bridge. And, foundation pit excavation changes the stress environment of adjacent bridge pile, reduces the lateral earth pressure of soil body to bridge pile, causes the settlement of soil body around bridge pile, thereby reduces the vertical bearing capacity of bridge pile.

[0003] At present, in view of the above problems, the existing solution is to enclose a circle of support structure around each bridge pile, so as to realize the reinforcement of bridge pile, but the above-mentioned mode of enclosing support structure around each bridge pile is not only inconvenient for construction, but also needs to use more building materials, is easy to cause resource waste, and the cost is higher;And do not monitor the bridge in the construction process, cannot find whether the bridge is settlement or inclination in time, also cannot judge whether the support structure is effective, and the safety hidden danger is bigger. UTILITY MODEL CONTENT

[0004] The main purpose of the utility model is to provide a protection monitoring system for adjacent bridge during subway foundation pit excavation, which aims at solving the technical problems of high cost and high safety hidden danger.

[0005] To achieve the above object, the utility model provides a protection monitoring system for adjacent bridge during subway foundation pit excavation, which comprises:

[0006] The protection structure comprises a concrete isolation layer and a continuous wall, the bridge comprises a top beam, a plurality of bridge piles located underground and a pier supported on the top of each bridge pile, the top beam is supported on the pier, the concrete isolation layer is arranged between the bridge pile and the foundation pit, the side wall of the foundation pit close to the bridge is provided with the continuous wall correspondingly, and a grouting reinforcement layer is formed between the continuous wall and the concrete isolation layer;The bridge deck of the top beam is provided with a plurality of first monitoring points along the length direction, and each pier is provided with a second monitoring point.

[0007] The monitoring device comprises a level and an inclinometer, the level is used to monitor the level elevation value at each first monitoring point, and the inclinometer is used to monitor the inclination angle of the pier at each second monitoring point.

[0008] In an embodiment, the concrete isolation layer comprises a plurality of cast-in-situ bored piles arranged in sequence and at intervals along the extension direction of the concrete isolation layer, and each cast-in-situ bored pile is a concrete pile.

[0009] In an embodiment, the plurality of cast-in-situ bored piles are arranged at equal intervals, and the interval distance is equal to the diameter of the cast-in-situ bored pile.

[0010] In an embodiment, the cast-in-situ bored pile comprises a steel sleeve and a concrete column formed inside the steel sleeve.

[0011] In an embodiment, a steel reinforcement cage is arranged inside the steel sleeve and is arranged vertically and located in the concrete column.

[0012] In an embodiment, the cast-in-situ bored pile is arranged at equal intervals vertically with the continuous wall.

[0013] In an embodiment, the underground depth of the cast-in-situ bored pile is greater than the underground depth of the bridge pile; and / or, the underground depth of the cast-in-situ bored pile is greater than the underground depth of the foundation pit.

[0014] In an embodiment, at least part of the cast-in-situ bored pile and at least part of the continuous wall are exposed on the ground.

[0015] In an embodiment, the continuous wall is provided with a rotary jet pile at both ends in the horizontal direction, and the rotary jet pile is arranged vertically.

[0016] In an embodiment, the expansion joint of the top beam is arranged with a third monitoring point, and the monitoring device further comprises a displacement monitor, which is used to monitor the displacement distance of the expansion joint of the top beam at the third monitoring point.

[0017] The utility model discloses a protection monitoring system, through adopting the protection structure, the protection structure includes setting the concrete isolation layer between bridge pile and foundation pit and setting the continuous wall on the side wall of foundation pit close to bridge, can effectively insulate the influence of foundation pit excavation to bridge pile, reduces the problem of bridge pile vertical bearing capacity drop due to soil settlement, and, the soil stability is further improved with the addition of grouting reinforcement layer, and the lateral earth pressure of bridge pile is strengthened, thereby the overall stability of bridge pile and surrounding soil is improved, and, grouting reinforcement layer also serves as water stop curtain, especially under the condition of water-rich complex stratum, can effectively prevent water body penetration between bridge pile and station foundation pit, avoids the adverse effect of deformation settlement of bridge pile caused by soil softening, is also beneficial to keeping the water level outside foundation pit stable during foundation pit excavation, compared with the mode of surrounding protection structure for each bridge pile in the prior art, the utility model discloses the concrete isolation layer and continuous wall between bridge and foundation pit are arranged to reach the purpose of protecting bridge, not only simplifies the construction process, but also reduces the quantity of required materials, thereby reduce the cost, improve the economic benefit, in addition, through adopting monitoring equipment, the level instrument and the inclination instrument of monitoring equipment can continuously monitor the state change of bridge during and after construction, through regularly or real-time monitoring the level elevation value of first monitoring point position on roof beam and the inclination angle data of second monitoring point position of bridge pier, whether the bridge has settlement or inclination phenomenon can be found in time, and then the effectiveness and safety of protection structure are evaluated, so that the foundation pit excavation can be stopped in time or the protection structure is further strengthened, and the potential safety hazard is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, below will be to the embodiment or prior art description needed to use the drawing briefly introduced, obviously, the drawing in the following description only some embodiments of the utility model, for those skilled in the art, under the premise of not paying the creative labor, still can obtain other drawings according to the structure shown by these drawings.

[0019] Fig. 1 It is the side view of the protection structure in the protection monitoring system embodiment provided by the utility model;

[0020] Fig. 2 It is the top view of the protection structure in the protection monitoring system embodiment provided by the utility model;

[0021] Fig. 3 It is the schematic diagram of arranging first monitoring point position, second monitoring point position and third monitoring point position on the bridge in the protection monitoring system embodiment provided by the utility model.

[0022] EXPLANATION OF DRAWINGS:

[0023] 100, protection structure; 1, concrete isolation layer; 11, cast-in-place pile; 2, continuous wall; 3, grouting reinforcement layer;

[0024] 200, bridge; 201, top beam; 211, first monitoring point; 212, second monitoring point; 202, bridge pile; 203, bridge pier; 213, third monitoring point;

[0025] 300, foundation pit.

[0026] The realization, functional features and advantages of the utility model will be further described with reference to the drawings in combination with embodiments. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0028] It should be noted that if the embodiments of the utility model involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture, and if the specific posture changes, the directional indications also change accordingly.

[0029] In addition, if the embodiments of the utility model involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one feature. In addition, if "and / or" or "and / or" appears in the entire text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skill in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0030] With the rapid development of economy and technology and the continuous advancement of urbanization in China, the demand for subways in cities is increasing. In the process of subway construction, the excavation of subway foundation pits will cause stress disturbance to adjacent bridges, leading to the destruction of bridge piles and piers and affecting the long-term stability of the bridges. Moreover, the excavation of foundation pits changes the stress environment of adjacent bridge piles, reduces the lateral earth pressure of the soil on the bridge piles, causes the surrounding soil of the bridge piles to settle, and thus reduces the vertical bearing capacity of the bridge piles.

[0031] At present, in order to solve the above problems, the existing solution is to surround each bridge pile with a supporting structure, thereby reinforcing the bridge pile. However, the above-mentioned method of surrounding each bridge pile with a supporting structure is not only inconvenient for construction, but also requires the use of a large amount of building materials, which is prone to resource waste and high cost. Moreover, the bridge is not monitored during construction, so it is impossible to timely discover whether the bridge has settled or tilted, and thus it is impossible to determine whether the supporting structure is effective, which has a large safety hazard.

[0032] The utility model provides a kind of protection monitoring system for adjacent bridge during subway foundation pit excavation period.

[0033] Please refer to Figs. 1-3 In an embodiment of the utility model, the protection monitoring system includes a protection structure 100 and a monitoring device. The protection structure 100 includes a concrete isolation layer 1 and a continuous wall 2. The bridge 200 includes a top beam 201, multiple bridge piles 202 located underground, and piers 203 supported on the top of each bridge pile 202. The top beam 201 is supported on the piers 203. The concrete isolation layer 1 is arranged between the bridge piles 202 and the foundation pit 300. The side wall of the foundation pit 300 close to the bridge 200 is provided with the continuous wall 2 correspondingly, and a grouting reinforcement layer 3 is formed between the continuous wall 2 and the concrete isolation layer 1. The bridge deck of the top beam 201 is provided with multiple first monitoring points 211 along the length direction thereof at intervals. Each pier 203 is provided with a second monitoring point 212. The monitoring device includes a level and an inclinometer. The level is used to monitor the level elevation value at each first monitoring point 211. The inclinometer is used to monitor the inclination angle of the pier 203 at each second monitoring point 212.

[0034] The utility model discloses a protection monitoring system, through adopting protection structure 100, protection structure 100 includes setting concrete isolation layer 1 between bridge pile 202 and foundation pit 300 and setting continuous wall 2 on the side wall of foundation pit 300 close to bridge 200, can effectively insulate the influence of foundation pit 300 excavation to bridge pile 202, reduce the problem of bridge pile 202 vertical bearing capacity drop due to soil settlement, simultaneously, the joining of grouting reinforcement layer 3 further improves the stability of soil, strengthens the lateral earth pressure of bridge pile 202, thereby improves the overall stability of bridge pile 202 and the soil body around it, and, grouting reinforcement layer 3 also serves as water stop curtain, especially under the condition of water-rich complex stratum, can effectively prevent the water body penetration between bridge pile 202 and station foundation pit 300, avoids the adverse effect such as deformation settlement of bridge pile 202 caused by soil softening, also is beneficial to keeping the water level outside foundation pit 300 stable during the excavation of foundation pit 300, compared with the mode of protection structure 100 surrounding each bridge pile 202 in prior art, the protection structure 100 reaches the purpose of protecting bridge 200 by setting concrete isolation layer 1 and continuous wall 2 between bridge 200 and foundation pit 300, not only simplifies the construction process, but also reduces the quantity of required materials, thereby reduces the cost, improves the economic benefit, in addition, by adopting monitoring equipment, the monitoring equipment includes level and inclinometer, can continuously monitor the state change of bridge 200 during and after construction, by regularly or real-time monitoring the level elevation value of first monitoring point 211 on roof beam 201 and the inclination angle data of second monitoring point 212 of pier 203, whether bridge 200 exists settlement or inclination phenomenon can be discovered in time, further evaluates the effectiveness and safety of protection structure 100, to be able to stop foundation pit 300 excavation in time or further strengthen protection structure 100, greatly reduces the potential safety hazard.

[0035] It should be noted that the continuous wall 2 can be constructed by using the existing continuous wall 2 construction process.

[0036] In an embodiment, the concrete isolation layer 1 includes a plurality of bored piles 11 arranged in sequence along the extension direction of the concrete isolation layer 1, and each bored pile 11 is a concrete pile.

[0037] It can be understood that the bored pile 11, as a concrete pile, has high strength and durability, can effectively block the stress disturbance generated during the excavation of the foundation pit 300, and prevent it from having an adverse effect on the bridge pile 202 and the pier 203. This structure can provide a solid barrier to reduce the disturbance of the surrounding soil during the excavation of the foundation pit 300, and protect the bridge pile 202 from damage; and, compared with traditional precast piles or other types of pile foundations, the construction process of the bored pile 11 is more simple and fast, the bored pile 11 can be directly cast on site, without the need to transport heavy precast components, reducing logistics costs and time costs, and the bored pile 11 can be formed using existing construction processes; in addition, the interval arrangement is not only conducive to cost savings, but also does not interfere with each other during construction.

[0038] In an embodiment, the plurality of bored piles 11 are arranged at equal intervals, and the interval distance is equal to the diameter of the bored pile 11.

[0039] It can be understood that the bored piles 11 arranged at equal intervals can ensure that the stress generated during the excavation of the foundation pit 300 is evenly distributed on each pile foundation, avoiding structural damage caused by local stress concentration. This can more effectively protect the bridge pile 202 and the pier 203 and improve the stability of the entire structure. When the interval distance is equal to the diameter of the bored pile 11, the distance between the bored piles 11 is moderate, neither increasing the construction difficulty because the distance is too small, nor weakening the connection strength between the piles because the distance is too large. This layout helps to form a relatively tight overall structure and improve the overall stiffness of the concrete isolation layer 1.

[0040] In an embodiment, the bored pile 11 includes a steel sleeve and a concrete column formed inside the steel sleeve.

[0041] It can be understood that the composite structure formed by the steel sleeve and the concrete column combines the high strength of steel and the good compression resistance of concrete, significantly improving the load-bearing capacity of the bored pile 11; in addition, during the construction process of the bored pile 11, the steel sleeve can effectively prevent the drill hole from collapsing and affecting the bridge 200.

[0042] In an embodiment, a steel reinforcement cage is arranged inside the steel sleeve, and the steel reinforcement cage is arranged vertically and located in the concrete column.

[0043] It can be understood that the steel reinforcement cage can significantly improve the compression and tensile properties of the concrete column, and the steel and concrete work together, with the steel bearing the tensile force and the concrete bearing the compressive force, making the entire bored pile 11 structure more stable. The steel reinforcement cage can effectively prevent the concrete column from developing fine cracks under long-term load, prolonging the service life of the pile foundation.

[0044] In an embodiment, the bored piles 11 are arranged equidistantly along the vertical direction between the continuous wall 2.

[0045] It can be understood that the equidistant arrangement of the bored piles 11 and the continuous wall 2 can ensure that the stress and load generated during the excavation of the foundation pit 300 are evenly distributed on the entire protective structure 100, avoiding structural damage caused by local stress concentration. The equidistant arrangement can maximize the role of each pile and the continuous wall 2, avoid unnecessary waste of resources, and reduce construction costs.

[0046] In an embodiment, the underground depth of the bored piles 11 is greater than the underground depth of the bridge piles 202; and / or, the underground depth of the bored piles 11 is greater than the underground depth of the foundation pit 300.

[0047] It can be understood that the underground depth of the bored piles 11 being greater than the depth of the bridge piles 202 can ensure that the pile foundation forms an effective isolation barrier in a deeper stratum, preventing the stress disturbance generated during the excavation of the foundation pit 300 from being transmitted to the bridge piles 202; the depth being greater than the depth of the foundation pit 300 can ensure that the bored piles 11 can cover the bottom of the foundation pit 300 during the excavation of the foundation pit 300, providing all-round protection and avoiding adverse effects of the soil at the bottom of the foundation pit 300 on the bridge piles 202.

[0048] In an embodiment, at least part of the bored piles 11 and at least part of the continuous wall 2 are exposed on the ground.

[0049] It can be understood that the part exposed on the ground can facilitate observation of the verticality of the bored piles 11 and the continuous wall 2, and also prevent the flow of ground soil from damaging the stability of the ground.

[0050] In an embodiment, the continuous wall 2 is provided with rotary jet piles at both ends in the horizontal direction, and the rotary jet piles are arranged in the vertical direction.

[0051] It can be understood that the rotary jet piles can enhance the stability of the ends of the continuous wall 2, prevent the ends of the continuous wall 2 from slipping or collapsing during the excavation of the foundation pit 300, the solidified soil formed by the rotary jet piles has good waterproof performance, which can further improve the waterproof effect of the entire supporting structure, the rotary jet piles can form an anti-seepage curtain, effectively preventing underground water from penetrating into the foundation pit 300 through the ends of the continuous wall 2, reducing the water level in the foundation pit 300, and reducing the construction difficulty and risk.

[0052] It should be noted that the rotary jet piles can be constructed using the construction technology in the prior art.

[0053] For example, Fig. 3As shown in (c) in the figure, in an embodiment, the expansion joint of the top beam 201 is arranged with a third monitoring point 213, and the monitoring device further comprises a displacement monitor, which is used for monitoring the displacement distance of the expansion joint of the top beam 201 at the third monitoring point 213.

[0054] It can be understood that the displacement monitor can accurately measure the displacement distance of the expansion joint, provide real-time data, help construction personnel and management personnel understand the actual state of the expansion joint in time, and through real-time monitoring of the displacement of the expansion joint, an early warning can be sent in time when the expansion joint abnormally changes, potential safety hazards are avoided, and the displacement monitor can adopt a monitor in the prior art.

[0055] The specific construction process of the utility model is as follows:

[0056] (1) erecting the cast-in-place pile 11 as the concrete isolation layer 1 to isolate the influence of the excavation of the foundation pit 300 on the bridge pile 202, and the cast-in-place pile 11 is poured with C30 plain concrete.

[0057] (2) erecting the continuous wall 2 to strengthen the horizontal support stiffness of the enclosure structure of the foundation pit 300 and prevent the lateral displacement of the foundation pit 300.

[0058] (3) grouting the grouting reinforcement layer 3 between the concrete isolation layer 1 and the continuous wall 2 as a waterproof curtain to ensure that the water level outside the foundation pit 300 remains stable during the construction of the foundation pit 300.

[0059] (4) arranging the first monitoring point 211 on the bridge 200, the second monitoring point 212 on the pier 203 and the third monitoring point 213 at the expansion joint of the top beam 201 to realize the monitoring of the bridge 200.

[0060] The above-described is only an exemplary embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation made by using the utility model specification and the drawings, or direct / indirect application in other related technical fields is included in the patent protection range of the utility model.

Claims

1. A subway foundation pit excavation period protection monitoring system for a nearby bridge, characterized in that, The application relates to a bridge protection structure. The bridge protection structure comprises a concrete isolation layer and a continuous wall, the bridge comprises a top beam, a plurality of bridge piles underground and bridge piers supported on top of the bridge piles, the top beam is supported on the bridge piers, the concrete isolation layer is arranged between the bridge piles and a foundation pit, the continuous wall is arranged corresponding to the side wall of the bridge pit, and a grouting reinforcement layer is formed between the continuous wall and the concrete isolation layer; a bridge deck of the top beam is provided with a plurality of first monitoring points along the length direction of the bridge deck, and each bridge pier is provided with a second monitoring point. The monitoring device comprises a level meter and an inclinometer, the level meter is used for monitoring the level elevation value at each first monitoring point, and the inclinometer is used for monitoring the inclination angle of the bridge pier at each second monitoring point.

2. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 1, wherein, The concrete isolation layer comprises a plurality of bored piles arranged in sequence along the extension direction of the concrete isolation layer, and each bored pile is a concrete pile.

3. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 2, wherein, The plurality of bored piles are arranged at equal intervals, and the interval distance is equal to the diameter of the bored pile.

4. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 2, wherein, The bored pile comprises a steel sleeve and a concrete column formed in the steel sleeve.

5. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 4, wherein, The steel sleeve is provided with a steel reinforcement cage arranged vertically in the concrete column.

6. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 2, wherein, Vertically, the bored pile and the continuous wall are arranged at equal intervals.

7. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 2, wherein, The underground depth of the bored pile is greater than the underground depth of the bridge pile, and / or the underground depth of the bored pile is greater than the underground depth of the foundation pit.

8. The monitoring system for protecting the adjacent bridge during the excavation of the subway foundation pit according to claim 2, wherein, At least part of the bored pile and at least part of the continuous wall are exposed on the ground.

9. The monitoring system for protecting a nearby bridge during a subway foundation excavation period according to any one of claims 1 to 8, wherein The continuous wall is provided with a rotary jetting pile at both ends in the horizontal direction, and the rotary jetting pile is arranged vertically.

10. The monitoring system for protecting a nearby bridge during a subway foundation excavation period according to any one of claims 1 to 8, wherein The expansion joint of the top beam is provided with a third monitoring point, and the monitoring device further comprises a displacement monitor used for monitoring the displacement distance of the expansion joint of the top beam at the third monitoring point.

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