Subway entrance and exit ramp section structure and construction method

Abstract

The application discloses a subway entrance and exit slope section structure and a construction method thereof, which comprises a climbing section, a top flat section, a bottom flat section, a first fixed connection section, a second fixed connection section, a water collecting section integrally connected with the second fixed connection section and a surrounding structure arranged on both sides of the climbing section; the climbing section is arranged between the top flat section and the bottom flat section; the first fixed connection section is used for connecting the top flat section and the climbing section; the second fixed connection section is used for connecting the bottom flat section and the climbing section; the first fixed connection section, the second fixed connection section and the surrounding structure surround the climbing section; the climbing section comprises a slope body, a cushion layer arranged on the surface of the slope body, a plurality of groups of steel bar assemblies arranged in the slope direction of the cushion layer, a plurality of steel pipes fixedly connected with the steel bar assemblies, and the steel pipes penetrating through the cushion layer and vertically inserted into the slope body. The subway entrance and exit slope section structure and the construction method thereof have the advantages that the climbing section and the cushion layer cannot slide, there is no construction joint at the junction of the climbing section and the flat section, and the risk of water leakage is avoided.

Description

Technical Field

[0001] This invention relates to the field of subway construction technology, and in particular to a subway entrance / exit ramp structure and construction method. Background Technology

[0002] With the rapid development of modern urban industries and the continuous expansion of urban scale, subways and urban rail transit play an important role in solving traffic congestion problems. The station concourse and platform levels of subway stations are often located underground, and the entrances and exits are the connecting passages for passengers from the ground to the underground station.

[0003] Currently, the steep incline of the entrance and exit sections poses a significant risk of landslides during the excavation and foundation pouring stages. Furthermore, the straight section at the top of the entrance and exit utilizes the SMW (Self-Modified Welded) method, with I-beams inserted into the piles. During construction at the top of the incline, the steel sections within the SMW piles are not yet removed, preventing the simultaneous pouring of concrete for the incline and the straight section. This creates a construction joint, increasing the risk of water leakage at the interface between the old and new concrete, slowing down construction speed, and extending the construction period. Therefore, preventing landslides on the entrance and exit slopes to reduce construction risks, while simultaneously accelerating the construction of both the incline and the straight section and minimizing the construction joint, presents a significant technical challenge.

[0004] Therefore, this paper proposes a subway entrance ramp structure and construction method to address the shortcomings of existing technologies. Summary of the Invention

[0005] This invention provides a structure and construction method for a ramp section at a subway entrance, aiming to solve the problems of easy slippage in the ramp section and subbase, and the construction joint at the junction of the ramp section and the straight section, which leads to the risk of water leakage in the later stage.

[0006] The present invention adopts the following technical solution:

[0007] A subway entrance ramp structure includes a climbing section, a top straight section, a bottom straight section, a first fixed section, a second fixed section, a water collection section integrally connected to the second fixed section, and a retaining structure disposed on both sides of the climbing section.

[0008] The climbing section is located between the top straight section and the bottom straight section. The first fixed section is used to connect the top straight section and the climbing section. The second fixed section is used to connect the bottom straight section and the climbing section. The first fixed section, the second fixed section, and the enclosure structure enclose the climbing section.

[0009] The climbing section includes a slope body, a cushion layer laid on the surface of the slope body, several sets of steel reinforcement assemblies laid in the slope direction of the cushion layer, and several steel pipes fixedly connected to the steel reinforcement assemblies. The steel pipes penetrate the cushion layer and are vertically inserted into the slope body.

[0010] As a further improvement to the technical solution of the present invention, the first fixed connection section includes a non-insulated triaxial mixing pile and an insulated triaxial mixing pile arranged side by side with the non-insulated triaxial mixing pile. The non-insulated triaxial mixing pile is located at the end away from the climbing section, and the insulated triaxial mixing pile is located at the end close to the climbing section.

[0011] As a further improvement to the technical solution of the present invention, the height H of the climbing section is 0m-15m;

[0012] When the height H of the climbing section is less than or equal to 10m, two rows of steel reinforcement components are evenly arranged along the slope direction of the slope body.

[0013] When the height of the climbing section is 10m < H ≤ 15m, three rows of steel reinforcement components are evenly arranged along the slope direction of the slope body.

[0014] As a further improvement to the technical solution of the present invention, the steel reinforcement assembly includes a plurality of transverse steel bars and a plurality of longitudinal steel bars arranged perpendicularly to the transverse steel bars, and the two ends of the transverse steel bars are respectively connected to the enclosure structure;

[0015] The reinforcing bar assembly has a grid-like structure and an opening for inserting the steel pipe.

[0016] As a further improvement to the technical solution of the present invention, the steel pipes are evenly arranged along the width direction of the slope body, and the outer peripheral wall of the steel pipes is fixedly connected to the transverse reinforcing bars and the longitudinal reinforcing bars.

[0017] As a further improvement to the technical solution of the present invention, the retaining structure is an SWM method pile retaining structure.

[0018] As a further improvement to the technical solution of the present invention, it also includes an upper support section of the entrance escalator located at the end of the top straight section away from the climbing section, the upper support section of the entrance escalator and the first fixed section surrounding the top straight section.

[0019] A construction method for a subway entrance / exit ramp section, applicable to the aforementioned subway entrance / exit ramp section structure, comprising the following steps:

[0020] S1. Before the earthwork of the auxiliary foundation pit is completed, firstly, construct the SMW method pile retaining structure according to the outer contour of the auxiliary foundation pit structure.

[0021] S2. A first fixed section is installed at the junction of the top straight section and the top of the climbing section to seal the enclosure structure, and a second fixed section is installed at the junction of the bottom straight section and the bottom of the climbing section.

[0022] S3. After the second reinforcement section is installed, the integrated reinforcement of the water collection well is connected as a whole, and it is checked whether the design strength is achieved.

[0023] S4. Excavate the earthwork of the auxiliary foundation pit. After the excavation of the climbing section is completed, lay a cushion layer on the surface of the climbing section.

[0024] S5. Lay steel reinforcement assemblies evenly above the subgrade along the slope direction, drive several steel pipes into the steel reinforcement assemblies and fix them, and then grout into the steel pipes.

[0025] As a further improvement to the technical solution of the present invention, in step S1, after the construction of the SMW method pile retaining structure is completed, the foundation pit of the support section on the entrance escalator is excavated by slope excavation.

[0026] As a further improvement to the technical solution of the present invention, in step S2, the outer row of the first fixed connection section adopts non-cased triaxial mixing piles, while the inner row adopts cased triaxial mixing piles, and no I-beams are inserted into the triaxial mixing columns.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The proposed subway entrance / exit ramp structure and construction method reinforces the bottom straight section by installing a second reinforcing section before excavation of the auxiliary foundation pit, and integrates the water collection well into a single unit. During the excavation of the ramp section foundation pit, steel reinforcement components and steel pipes are added to the ramp section. To increase the rigidity of the steel pipes, cement mortar is injected inside, effectively solving the problem of downward slippage of the soil and subgrade in the ramp section of the entrance / exit, and mitigating the significant construction risk of slippage in the ramp section of the auxiliary structure. Simultaneously, a first reinforcing section is installed at the junction of the ramp section and the top straight section, avoiding the existence of construction joints between the ramp and straight sections, effectively solving the problem of water leakage at construction joints, and increasing the safety of the foundation pit. This subway entrance / exit ramp structure and construction method features no slippage of the ramp section and subgrade, no construction joints at the junction of the ramp and straight sections, and avoids the risk of water leakage. Attached Figure Description

[0029] The technology of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0030] Figure 1 This is a schematic diagram of the foundation pit cross-section of the slope section of the subway entrance and exit, and the construction method.

[0031] Figure 2 This is a schematic diagram of the foundation pit structure and construction method of the ramp section at the subway entrance / exit;

[0032] Figure 3 This is a schematic diagram of the sloping section structure and construction method of the subway entrance / exit ramp;

[0033] Figure 4 It is a detailed drawing of the steel reinforcement components for the structure and construction method of the ramp section at the subway entrance;

[0034] Figure 5 This is a detailed drawing of the second fixed section of the three-axis mixing pile, which illustrates the structure and construction method of the subway entrance ramp section.

[0035] Figure label:

[0036] 1. Climbing section; 11. Slope body; 12. Subbase; 13. Reinforcing steel assembly; 131. Transverse reinforcement; 132. Longitudinal reinforcement; 133. Opening; 14. Steel pipe;

[0037] 2. Straight section at the top;

[0038] 3. Bottom straight section; 4. First fixed connection section; 41. Non-cased triaxial mixing pile; 42. Casing triaxial mixing pile;

[0039] 5. Second fixed section; 6. Water collection section; 7. Enclosure structure; 71. I-beam; 8. Upper support section of entrance and exit escalator. Detailed Implementation

[0040] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The same reference numerals used throughout the accompanying drawings indicate the same or similar parts.

[0041] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "up," "down," "left," and "right" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.

[0042] A subway entrance / exit ramp structure and construction method, referring to Figures 1 to 5 It includes a climbing section 1, a top straight section 2, a bottom straight section 3, a first fixed section 4, a second fixed section 5, and a retaining structure 7;

[0043] The retaining structure 7 is set on both sides of the climbing section 1; the climbing section 1 is set between the top straight section 2 and the bottom straight section 3. The first fixed section 4 is used to connect the top straight section 2 and the climbing section 1, and the second fixed section 5 is used to connect the bottom straight section 3 and the climbing section 1. The first fixed section 4, the second fixed section 5 and the retaining structure 7 enclose the climbing section 1; the climbing section 1 includes the slope body 11, the cushion layer 12 laid on the surface of the slope body 11, several sets of steel reinforcement assemblies 13 laid on the slope direction of the cushion layer 12, and several steel pipes 14 fixedly connected to the steel reinforcement assemblies 13. The steel pipes 14 penetrate the cushion layer 12 and are vertically inserted into the slope body 11. The cushion layer 12 is made of 1.5m thick C20 early strength concrete; the retaining structure 7 is an SWM method pile retaining structure 7; the water collection section 6 is integrally connected with the second fixed section.

[0044] By reinforcing the bottom straight section 3 with a second connecting section 5 before the excavation of the auxiliary foundation pit, and integrating the water collection well into a single unit, a steel reinforcement assembly 13 and steel pipe 14 are added to the slope section during excavation. To increase the rigidity of the steel pipe 14, cement mortar is injected inside the steel pipe 14, which effectively solves the problem of downward slippage of the soil and cushion layer 12 in the entrance / exit climbing section 1, thus mitigating the significant construction risk of slippage in the auxiliary structure climbing section 1. Simultaneously, a first connecting section 4 is installed at the junction of the entrance / exit climbing section 1 and the top straight section 2, avoiding the existence of a construction joint between the entrance / exit climbing section 1 and the straight section, effectively solving the problem of water leakage at the construction joint, and increasing the safety of the foundation pit. This subway entrance / exit slope section structure and construction method features that the climbing section 1 and cushion layer 12 will not slip, and there is no construction joint at the junction of the climbing section 1 and the straight section, avoiding the risk of water leakage.

[0045] In one embodiment, the first fixed section 4 includes a non-insulated triaxial mixing pile 41 and an inserted triaxial mixing pile 42 arranged side by side. The non-insulated triaxial mixing pile 41 is located at the end away from the climbing section 1, and the inserted triaxial mixing pile 42 is located at the end closer to the climbing section 1. In order to enable the continuous pouring of the concrete structure of the slope section and the concrete structure of the top straight section 2, no I-beams are inserted into the first fixed section 4 at the junction of the top straight section 2 and the slope section. The cement content of the first fixed section 4 is 20%, and the first fixed section 4 is inserted to the waterproof layer ≥ 1.5m. The triaxial mixing pile is a φ850@600 triaxial mixing pile. The triaxial mixing pile is a type of long spiral pile machine with three spiral drilling holes. During construction, the three spiral drilling holes are drilled downwards simultaneously.

[0046] During the construction of the main structure of the entrance and exit ramp section 1, since the connection between the top straight section 2 and the top of the ramp section 1 consists only of the outer row of non-inserted triaxial mixing piles 41 and the inner row of insered triaxial mixing piles 42, and no I-beams 71 are inserted in either the non-inserted triaxial mixing piles 41 or the insered triaxial mixing piles 42, the triaxial mixing piles can be directly removed. This allows the structural slab of the entrance and exit ramp section 1 to be tied and poured together with the structural steel reinforcement of the top straight section 2, reducing one construction joint and avoiding the risk of water leakage at the construction joint later. At the same time, it speeds up the construction period and reduces the project risk.

[0047] In one embodiment, to prevent slippage between the foundation layer 12 of the entrance / exit ramp section 1 and the soil, during the construction of the concrete foundation layer 12, a grid-shaped steel reinforcement is laid according to the height of the entrance / exit ramp section 1; the height H of the ramp section 1 is 0m-15m; when the height H of the ramp section 1 is ≤10m, two rows of steel reinforcement assemblies 13 are evenly arranged along the slope direction of the slope body 11; when the height of the ramp section 1 is 10m < H ≤15m, three rows of steel reinforcement assemblies 13 are evenly arranged along the slope direction of the slope body 11; the steel reinforcement assembly 13 includes several transverse steel bars 131 and several longitudinal steel bars 132 intersecting with the transverse steel bars 131, with both ends of the transverse steel bars 131 connected to the retaining structure 7; the steel reinforcement assembly 13 has a grid-shaped structure, and the steel reinforcement assembly 13 is provided with There is an opening 133 for inserting steel pipe 14; the steel pipe 14 is made of steel with a diameter of 48mm and a wall thickness of 3mm, and the gap of the opening 133 is 50mm, which facilitates the vertical installation of the 48mm diameter steel pipe 14 into the slope body 11; the steel pipe 14 is set at intervals of 1m along the width direction of the slope body 11, and the outer peripheral wall of the steel pipe 14 is fixedly connected to the transverse steel bar 131 and the longitudinal steel bar 132. The length of the steel pipe 14 is 2m, and the length of the steel pipe 14 can be appropriately adjusted according to the soil layer under the climbing section 1. The steel pipe 14 should be driven into the better soil layer under the climbing section 1 to play the role of fixing the cushion layer 12 of the climbing section 1; both the transverse steel bar 131 and the longitudinal steel bar 132 are made of φ25mm HPB400 grade steel bars, and the transverse steel bar 131 is 2m long.

[0048] In one embodiment, after the retaining structure 7 is closed with the first fixed section 4, a second fixed section 5 is installed at the connection between the bottom of the climbing section 1 and the bottom straight section 3. The end of the second fixed section 5 away from the climbing section 1 is fixedly connected to the water collection section 6, which can better prevent the climbing section 1 from sliding. The reinforcement depth of the second fixed section 5 is 2m, and the reinforcement depth of the water collection well is 2.5m. At this time, the cement content of the second fixed section 5 is 14% for solid mixing and 7% for air mixing. The horizontal width of the second fixed section 5 extends from the connection between the bottom of the climbing section 1 and the bottom straight section 3 to the edge of the reinforcement of the bottom of the water collection well pit, and is connected with the reinforcement of the inlet and outlet water collection well as a whole to prevent the soil of the inlet and outlet climbing section 1 from sliding and causing casualties.

[0049] In one embodiment, the escalator also includes an upper support section 8 located at the end of the top straight section 2 away from the climbing section 1, and the upper support section 8 of the escalator and the first fixed section 4 enclose the top straight section 2.

[0050] The present invention provides a construction method for a subway entrance / exit ramp section, applicable to the aforementioned subway entrance / exit ramp section structure, comprising the following steps:

[0051] S1. Before the earthwork of the auxiliary foundation pit is completed, firstly, construct the SMW method pile retaining structure according to the outer contour of the auxiliary foundation pit structure. After the construction of the SMW method pile retaining structure is completed, the foundation pit of the support section on the entrance ladder is excavated by slope excavation.

[0052] S2. A first fixed section is installed at the junction of the top straight section and the top of the sloping section to seal the enclosure structure. The first fixed section is inserted into the waterproof layer by ≥1.5m. A second fixed section is installed at the junction of the bottom straight section and the bottom of the sloping section. The reinforcement depth of the second fixed section is 2m.

[0053] S3. After the second reinforcement section is installed, the horizontal width of the second reinforcement section is reinforced from the connection between the bottom of the slope section and the bottom straight section to the edge of the reinforcement at the bottom of the sump pit. The sump pit is reinforced as a whole and the reinforcement depth of the sump pit is 2.5m. The design strength is then checked.

[0054] S4. Excavate the earthwork of the auxiliary foundation pit. After the excavation of the climbing section is completed, lay a cushion layer on the surface of the climbing section.

[0055] S5. Lay steel reinforcement assemblies evenly above the subbase along the slope direction. After evenly driving several steel pipes with a spacing of 1m into the steel reinforcement assemblies, weld them in place and then grout into the steel pipes. The water-cement ratio of the grout is 1:1.

[0056] In step S5, S5.1, when the height H of the climbing section is less than or equal to 10m, two rows of steel reinforcement components are laid evenly along the slope direction of the slope body.

[0057] S5.2 When the height of the climbing section is 10m < H ≤ 15m, three rows of steel reinforcement components shall be evenly installed along the slope direction of the slope body.

[0058] In step S1, the foundation pit for the support section of the entrance escalator is excavated, that is, a slope is excavated from the ground level. Since the excavation depth of the foundation pit for the support section of the entrance escalator is relatively shallow, a slope excavation is adopted.

[0059] In step S2, the outer row of the first fixed connection section adopts non-inserted triaxial mixing piles, while the inner row adopts insered triaxial mixing piles, and no I-beams are inserted into the triaxial mixing columns.

[0060] Other aspects of the subway entrance ramp structure and construction method of this invention can be found in the prior art and will not be repeated here.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A ramp structure for a subway entrance / exit, characterized in that, It includes a climbing section, a top straight section, a bottom straight section, a first fixed section, a second fixed section, a water collection section integrally connected to the second fixed section, and a retaining structure set on both sides of the climbing section. The climbing section is located between the top straight section and the bottom straight section. The first fixed section is used to connect the top straight section and the climbing section. The second fixed section is used to connect the bottom straight section and the climbing section. The first fixed section, the second fixed section, and the enclosure structure enclose the climbing section. The climbing section includes a slope body, a cushion layer laid on the surface of the slope body, several sets of steel reinforcement assemblies laid in the slope direction of the cushion layer, and several steel pipes fixedly connected to the steel reinforcement assemblies. The steel pipes penetrate the cushion layer and are vertically inserted into the slope body. The first fixed connection section includes non-insulated triaxial mixing piles and insulated triaxial mixing piles arranged side by side with the non-insulated triaxial mixing piles. The non-insulated triaxial mixing piles are located at the end away from the climbing section, and the insulated triaxial mixing piles are located at the end close to the climbing section. The height H of the climbing section is 0m-15m; When the height H of the climbing section is less than or equal to 10m, two rows of steel reinforcement components are evenly arranged along the slope direction of the slope body. When the height of the climbing section is 10m < H ≤ 15m, three rows of steel reinforcement components are evenly arranged along the slope direction of the slope body. Neither the non-inserted triaxial mixing pile nor the inserted triaxial mixing pile has I-beams inserted inside, allowing the triaxial mixing pile to be directly removed. This enables the structural slab of the entrance / exit ramp section to be tied and poured together with the structural reinforcement of the top straight section, reducing a construction joint and avoiding the risk of water leakage at the construction joint later.

2. The subway entrance / exit ramp structure according to claim 1, characterized in that: The steel reinforcement assembly includes several transverse steel bars and several longitudinal steel bars that are perpendicularly intersecting the transverse steel bars. The two ends of the transverse steel bars are respectively connected to the enclosure structure. The reinforcing bar assembly has a grid-like structure and an opening for inserting the steel pipe.

3. The subway entrance / exit ramp structure according to claim 2, characterized in that: The steel pipes are evenly arranged along the width of the slope body, and the outer peripheral wall of the steel pipes is fixedly connected to the transverse and longitudinal reinforcing bars.

4. The subway entrance / exit ramp structure according to claim 1, characterized in that: The retaining structure is an SMW method pile retaining structure.

5. The subway entrance / exit ramp structure according to claim 1, characterized in that: It also includes an upper support section of the entrance escalator located at the end of the top straight section away from the climbing section, and the upper support section of the entrance escalator and the first fixed section enclose the top straight section.

6. A construction method for a ramp section at a subway entrance / exit, characterized in that, The method applicable to the subway entrance / exit ramp structure as described in claim 5 includes the following steps: S1. Before the earthwork of the auxiliary foundation pit is completed, firstly, construct the SMW method pile retaining structure according to the outer contour of the auxiliary foundation pit structure. S2. A first fixed section is installed at the junction of the top straight section and the top of the climbing section to seal the enclosure structure, and a second fixed section is installed at the junction of the bottom straight section and the bottom of the climbing section. S3. After the second reinforcement section is installed, the integrated reinforcement of the water collection well is connected as a whole, and it is checked whether the design strength is achieved. S4. Excavate the earthwork of the auxiliary foundation pit. After the excavation of the climbing section is completed, lay a cushion layer on the surface of the climbing section. S5. Lay steel reinforcement assemblies evenly above the subgrade along the slope direction, drive several steel pipes into the steel reinforcement assemblies and fix them, and then grout into the steel pipes.

7. The construction method for the ramp section of a subway entrance / exit as described in claim 6, characterized in that: In step S1, after the construction of the SMW method pile retaining structure is completed, the foundation pit of the support section on the entrance and exit escalator is excavated by slope excavation.

8. The construction method for the ramp section of a subway entrance / exit according to claim 6, characterized in that: In step S2, the outer row of the first fixed connection section adopts non-inserted triaxial mixing piles, while the inner row adopts insered triaxial mixing piles, and no I-beams are inserted into the triaxial mixing columns.

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