Deep-buried silt layer foundation newly-built channel supporting structure and construction method thereof

Abstract

The supporting structure mainly comprises first base plates and second base plates which are arranged on the two sides of the bottom face of a channel, supporting beams are transversely arranged on the left first base plate and the right first base plate, and the left side and the right side of each supporting beam and a retaining wall above the corresponding second base plate form an overall stress structure through joint bars; an inverted filter is backfilled between the outer side of the retaining wall and the side face of the channel, and a cover plate is placed at the upper end of the inverted filter. According to the newly-built channel supporting structure for the deeply-buried silt layer foundation and the construction method of the newly-built channel supporting structure, the construction period is greatly shortened, and the cost is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water conservancy new channel construction, in particular to a deep buried silt layer foundation new channel supporting structure and a construction method thereof. BACKGROUND

[0002] In the process of water conservancy new channel construction, deep buried silt layer poor geological conditions are often encountered. When the height of the channel slope is greater than 3 meters or the slope gradient is steeper than 1:3, the silt at the slope toe is difficult to support the upper soil body, and landslide danger occurs. Generally, the cement soil mixing pile treatment scheme is adopted to solve this problem. However, the cement soil mixing pile piling and pile body forming period is relatively long, and the dust generated will pollute the surrounding environment. The new channel has drainage requirements and needs to be completed and put into use before summer, so the construction period is required. How to speed up the construction progress under the premise of safety, environmental protection, quality and cost has become a problem to be solved.

[0003] Taking a water conservancy new channel as an example, the opening line width of the new channel top is 36m, the channel bottom width is 10m, the depth is 5-6m, and the river sides are residential buildings. According to the overall construction period requirement, it must be completed before summer of the year. If the new channel cannot be put into use before summer of the year, the flood will not be discharged in time, and the overflow flood will cause a large area of water damage.

[0004] The main difficulties faced by the water conservancy project are in the following three aspects: 1), progress: the current river needs to be completed and put into use before summer to meet the drainage function. If cement soil mixing pile reinforcement is adopted, the piling and pile body forming time is relatively long, and it is difficult to complete the construction before summer of the year.

[0005] 2), cost: the outside of the new channel is close to the land boundary, and there are residential buildings nearby, which do not have the condition of slope excavation. If concrete anti-slide piles are used for support, the engineering cost will increase, and drilling and binding steel bars will increase the construction period.

[0006] 3), environmental protection: the dry spraying method of cement soil mixing pile will produce a large amount of dust, and the wet spraying method will produce cement slurry overflow, which will pollute the surrounding environment. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a deep buried silt layer foundation new channel supporting structure and a construction method thereof, which greatly shortens the construction period and greatly reduces the cost.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is: The deep buried silt layer foundation newly built channel support structure, including the first pad plate, the second pad plate arranged at both sides of the channel bottom, the support beam is horizontally arranged on the first pad plate, and the support beam is integrally stressed with the retaining wall above the second pad plate through the inserted rib; the backfilling filter layer is backfilled between the outside of the retaining wall and the channel side, and the cover plate is placed on the upper end of the filter layer.

[0009] The first pad plate is a prefabricated concrete plate, and the second pad plate is a wood plate.

[0010] The second pad plate is arranged side by side with the first pad plate, the second pad plate is close to one side of the channel bottom edge and is laid into a surface along the length direction, and the first pad plate is close to the second pad plate and is arranged along the channel length direction.

[0011] The support beam is a prefabricated square concrete block, and the support beam is horizontally placed on the first pad plate and is arranged along the channel length direction.

[0012] A plurality of drainage pipes are pre-buried in the retaining wall, the drainage pipes are arranged obliquely, and the higher end of the drainage pipe points to the filter layer, and the lower end points to the water area in the channel.

[0013] The gap between the cover plate and the retaining wall is filled with a caulking agent.

[0014] The retaining wall is a cast-in-place concrete, the filter layer is gravel, and the cover plate is a prefabricated concrete.

[0015] The deep buried silt layer foundation newly built channel support construction method, the first pad plate and the second pad plate are arranged at both ends of the newly excavated channel bottom, the support beam is horizontally hoisted and placed on the top of the first pad plate, and the inserted rib is welded at both ends of the support beam; the formwork is erected on the upper portion of the second pad plate and the drainage pipe is pre-buried, the concrete is poured on the second pad plate to form the retaining wall; after maintenance, when the concrete of the retaining wall reaches the design strength, the outside is backfilled with gravel to form the filter layer; the cover plate is hoisted on the top of the filter layer, and finally the caulking agent is filled in the gap between the retaining wall and the cover plate.

[0016] The deep buried silt layer foundation newly built channel support construction method comprises the following steps: Step 1: the first pad plate and the support beam are accepted; Step 2, measure and lay out on the excavated channel ground, determine the positions of the first pad plate, the second pad plate and the support beam, and mark well; Step 3, hoist the support beam and the first pad plate and place the machinery; Step 4, retest and correct: retest the positions of the first pad plate, the second pad plate and the support beam, and correct them; Step 5, use the crane to hoist the first pad plate to the designed position; Step 6, place the second pad plate to the designed position; Step 7, use the crane to hoist the support beam on the top of the first pad plate; Step 8, the bar is welded at both ends of the support beam; Step 9, erect the retaining wall formwork on the second bed plate, and pre-bury the drain pipe inside the retaining wall to be poured; Step 10, pour the retaining wall on the second bed plate; Step 11, after the retaining wall reaches the design strength, backfill the gravel on the outside to form a filter layer; Step 12, hoist the cover plate on the upper part of the filter layer; Step 13, fill the gap between the cover plate and the cast-in-place retaining wall with a caulking agent.

[0017] The concrete retaining wall near the side of the channel slope surface is sequentially from top to bottom: the upper section is a vertical surface, the middle section is an inclined surface, and the lower section is a shoulder extending to the side of the filter layer.

[0018] The present application provides a new channel support structure for deep buried silt layer foundation and a construction method thereof, which has the following technical effects: 1) The present application uses a prefabricated support beam and a cast-in-place retaining wall to form an integrated support structure, which replaces the traditional cement soil mixing pile treatment scheme. The advantages of the present method are: 1) The construction period is shorter than that of the cement soil mixing pile, and the construction period is shortened from 3 months to 1.5 months, which speeds up the construction speed; 2) The investment cost of the method is lower than that of the cement soil mixing pile, and the cost is changed from the original 3.86 million per kilometer to 3.1 million; 3) The method does not reduce the design standard, and uses the support beam and the cast-in-place retaining wall as the support structure, adopts the assembly type and cast-in-place process combined construction process, hoists the prefabricated concrete block and the cast-in-place retaining wall, which is simple and convenient, and does not cause environmental pollution. In summary, the present method has the advantages of high quality, low price, high efficiency and environmental protection.

[0019] 2) The present application is a permanent support structure, and after implementation, no other support measures are needed, only the upper newly excavated slope needs to be hardened to prevent water flow from eroding the upper newly excavated soil.

[0020] 3) CN202022146790-A channel slope support structure in deep soft soil area, defects: (1) large number of cement mixing piles, which will pollute the surrounding environment; (2) long construction period of cement mixing piles, compared with cast-in-place concrete retaining wall, cement soil mixing pile needs at least 30 days from construction to forming.

[0021] CN202421288714-A new channel support structure near important buildings, defects: (1) the structure cannot solve the problem of deep buried silt layer foundation slope landslide; (2) long forming period of bored piles, at least 30 days are needed.

[0022] CN 215252645 U - A simple support structure for channel slope collapse control, defects: the structure cannot solve the problem of slope landslide containing deep silt.

[0023] The present application uses prefabricated support beams and cast-in-place retaining walls relative to the above-mentioned patent, which not only solves the problem of slope landslide, but also reduces cost, saves time, and reduces environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present application will be further described below in conjunction with the drawings and examples: Figure 1 is a cross-sectional view of a newly excavated channel in the present application.

[0025] Figure 2 is an installation cross-sectional view of the present application.

[0026] Figure 3 is Figure 2 a partially enlarged schematic view.

[0027] Figure 4 is a top view of the installation of the present application.

[0028] In the figure: first pad 1, second pad 2, support beam 3, insert 4, drain pipe 5, retaining wall 6, filter layer 7, cover plate 8, caulking agent 9, silty clay layer a, silt layer b, clay layer c. DETAILED DESCRIPTION

[0029] As shown in Figures 1-4 , the deep silt layer foundation new channel construction method, the first pad 1 and the second pad 2 are hoisted at both ends of the newly excavated channel bottom, the first pad 1 is a prefabricated concrete pad, and the second pad 2 is a wooden pad. The support beam 3 is hoisted horizontally and placed on the top of the first pad 1 and the second pad 2 (only the edge part) and supported by the first pad 1 and the second pad 2. The support beam 3 is a prefabricated concrete square support beam. The insert 4 is welded at both ends of the support beam 3, the formwork is erected on the upper part of the second pad 2, and the drain pipe 5 is pre-buried, the concrete is poured on the second pad 2 to form the retaining wall 6, after curing, the concrete of the retaining wall 6 reaches the design strength, the outside is backfilled with gravel to form the filter layer 7, and the cover plate 8 is hoisted on the top of the filter layer 7, which is prefabricated concrete.

[0030] Example 1 This method is applied to newly built channels, and the silt layer at the bottom of the channel (indicated by b in the figure) is usually less than 4m thick. When the silt thickness at the bottom of the channel is less than 2m, the support beam 3 can be omitted after calculation, and the retaining wall 6 can be used for support. When the width of the channel bottom is greater than 12m, this structure can also be used, but the number and cross-section of the support beam 3 need to be increased, and the economic efficiency is reduced.

[0031] In this project, the newly-built channel top opening line width L1 is 36 m, the channel bottom width L2 is 10 m, the depth H1 is 5-6 m, and the thickness of the silt layer b is 3 m.

[0032] Specifically, the deep-buried silt layer foundation newly-built channel construction method comprises the following steps: Step 1, the first pad 1 and the support beam 3 are accepted: after the first pad 1 and the support beam 3 are put into the field, their factory qualification certificates and performance test reports are checked, and their appearance quality, strength, size, integrity, and straightness are checked. After passing the inspection, they can be used.

[0033] Step 2, measurement and positioning: the channel ground is measured and laid out, and the positions of the first pad 1, the second pad 2, and the support beam 3 are positioned on the excavated channel using measuring instruments. The hoisting positions of each support beam 3 are marked with lime, so that the support beams 3 are arranged at equal intervals later.

[0034] Step 3, hoisting the support beam 3 and the first pad 1 and placing the machinery in position.

[0035] Step 4, re-measurement and correction: the positions of the first pad 1, the second pad 2, and the support beam 3 are re-measured, re-checked, and corrected.

[0036] Step 5, the first pad 1 is hoisted to the designed position by using a crane. The length, width, and thickness of the first pad 1 are 1 m, 0.5 m, and 0.1 m respectively. The first pad 1 is arranged along the length direction of the excavated channel at an interval of 3 m. The first pad 1 serves as a foundation for the support beam 3, preventing uneven settlement of the support beam 3 placed directly on the silt foundation. Meanwhile, the first pad 1 can be used as a temporary construction platform for construction personnel, facilitating the welding of the reinforcing bars 4 to the two ends of the support beam 3. Step 6, the second pad 2 is placed at the designed position. The length, width, and thickness of the second pad 2 are 5 m, 0.6 m, and 0.01 m respectively, and it is tightly laid. The second pad 2 facilitates the erection of the formwork of the retaining wall 6 by construction personnel. The wood pad has the advantages of low cost and light weight, facilitating laying. Since the subsequent cast-in-place concrete bottom has a large area, the self-weight can be evenly distributed, so the wood pad can bear the weight of the retaining wall, without the need for a precast concrete pad.

[0037] Step 7, hoisting the precast concrete support beam: the support beam 3 is hoisted to the top of the first pad 1 by using a crane. The support beam 3 forms an integral support structure with the concrete wall 6, supporting the side slope and preventing landslides.

[0038] Step 8, welding the reinforcing bars: eight reinforcing bars 4 with a length of 0.6 m and a diameter of 14 mm are welded to the two ends of the support beam 3; the reinforcing bars 4 are embedded in the retaining wall 6, so that the support beam 3 and the retaining wall 6 are connected to form a force-bearing whole.

[0039] Step 9, erecting the template and pre-embedding the drain pipe: erect the retaining wall template on the second pad 2, and pre-embed the drain pipe 5 with a diameter of 5 cm inside the retaining wall 6. The drain pipe 5 is a PVC pipe, arranged at an interval of 0.5 m. The drain pipe 5 is arranged obliquely, the water inlet of the drain pipe 5 is connected to the inverse filter layer 7, and the water outlet of the drain pipe 5 points to the channel water area. The function of the drain pipe 5 is to drain the seepage water in the soil behind the wall in time, and reduce the water pressure.

[0040] Step 10, pouring C25 plain concrete on the second pad 2 to form the retaining wall 6. The top width of the retaining wall 6 is 0.4 m, the bottom width is 1.7 m, the back slope is 1:0.6, and the wall height is 1.4 m. The function of the retaining wall 6 is to block the soil of the slope, but it is difficult to block the soil of the slope only by the retaining wall 6, and it is also necessary to form an integral support structure with the support beam 3 to prevent the slope from sliding.

[0041] Step 11, after the concrete retaining wall 6 reaches the design strength of 25 Mpa, backfill the gravel on the outside to form the inverse filter layer 7. The gravel plays a role of inverse filtration, preventing the seepage water from taking away the soil behind the wall. The top width of the inverse filter layer 7 is 2.1 m, and the slope of the soil side is 1:0.88.

[0042] The concrete retaining wall 6 near the slope side of the channel has the following structure from top to bottom: the upper section is a vertical surface, the middle section is an inclined surface, and the lower section is a shoulder extending to the side of the inverse filter layer 7. The purpose of such a setting is to make the retaining wall 6 narrow at the top and wide at the bottom, with a heavy foundation and good stability. At the same time, the vertical section at the top and the shoulder at the bottom facilitate the erection of the formwork for pouring concrete.

[0043] Step 12, after backfilling the gravel, hoist the cover plate 8 on the top of the inverse filter layer 7. The cover plate 8 is 5 m long, 2.1 m wide, and 0.2 m thick. The function of the cover plate 8 is to prevent the backfilled gravel from being taken away by the water flow.

[0044] Step 13, fill the gap between the cover plate 8 and the retaining wall 6 with the caulking agent 9 to ensure that the cover plate 8 is tightly connected to the retaining wall 6 without any gap. The function is to prevent the backfilled gravel from being sucked out of the gap by the water flow in the channel.

Claims

1. A support structure for newly constructed channels on foundations deeply buried in silt layers, characterized in that: The system includes a first pad (1) and a second pad (2) set on both sides of the bottom surface of the channel. The support beam (3) is arranged laterally on the first pad (1) on the left and right sides. The support beam (3) is connected to the retaining wall (6) above the second pad (2) by the reinforcing bar (4) to form an integral load-bearing structure. A filter layer (7) is backfilled between the outer side of the retaining wall (6) and the side of the channel. A cover plate (8) is placed on the upper end of the filter layer (7).

2. The support structure for newly constructed channels on a deep-buried silt layer foundation as described in claim 1, characterized in that: The first pad (1) is a precast concrete slab, and the second pad (2) is a wooden board.

3. The support structure for newly constructed channels on a deep-buried silt layer foundation as described in claim 2, characterized in that: The second pad (2) is arranged side by side with the first pad (1). The second pad (2) is laid on the side close to the bottom edge of the channel and is laid out in a surface along the length direction. The first pad (1) is close to the second pad (2) and is arranged at intervals along the length direction of the channel.

4. The support structure for newly constructed channels on a deep-buried silt layer foundation as described in claim 3, characterized in that: The support beam (3) is a precast square concrete block, and the support beam (3) is placed horizontally on the first pad (1) and arranged at intervals along the length of the channel.

5. The support structure for newly constructed channels on a deep-buried silt layer foundation according to claim 4, characterized in that: Multiple drainage pipes (5) are pre-embedded in the retaining wall (6). The drainage pipes (5) are arranged at an angle, with the higher end of the drainage pipe (5) pointing towards the filter layer (7) and the lower end pointing towards the water flow area in the channel.

6. The support structure for newly constructed channels on a deep-buried silt layer foundation as described in claim 5, characterized in that: The gap between the cover plate (8) and the retaining wall (6) is filled with sealant (9).

7. The support structure for newly constructed channels on a deep-buried silt layer foundation as described in claim 6, characterized in that: The retaining wall (6) is made of cast-in-place concrete, the filter layer (7) is made of crushed stone, and the cover plate (8) is made of precast concrete.

8. The method for constructing a new channel support structure on a deeply buried silt layer foundation according to claim 7, characterized in that: On both sides of the bottom of the newly excavated channel, a first pad plate (1) and a second pad plate (2) are arranged. The support beam (3) is horizontally hoisted and placed on the top of the first pad plate (1). Reinforcing bars (4) are welded at both ends of the support beam (3). A template and a pre-embedded drainage pipe (5) are erected on the second pad plate (2). Concrete is poured on the second pad plate (2) to form a retaining wall (6). After curing, the concrete of the retaining wall (6) reaches the design strength. Crushed stone is backfilled on the outside to form a filter layer (7). A cover plate (8) is hoisted on the top of the filter layer (7). Finally, sealant (9) is filled into the gap between the retaining wall (6) and the cover plate (8).

9. The method for constructing a new channel support structure on a deeply buried silt layer foundation according to claim 7, comprising the following steps: Step 1: Inspection of the first pad (1) and support beam (3) upon arrival at the site; Step 2: Measure and lay out the ground on the excavated channel to determine the positions of the first base plate (1), the second base plate (2), and the support beam (3), and mark them. Step 3: Hoist the support beam (3) and the first pad (1) into place mechanically; Step 4, re-measurement and correction: Re-measure the positions of the first pad (1), the second pad (2) and the support beam (3), check each position and make corrections; Step 5: Use a crane to lift the first pad (1) to the designed position; Step 6: Place the second pad (2) in the designed position; Step 7: Use a crane to hoist the support beam (3) onto the top of the first pad (1); Step 8: Weld the reinforcing bars (4) to both ends of the support beam (3); Step 9: Install the retaining wall template on the second pad (2) and pre-embed the drainage pipe (5) inside the retaining wall (6) to be poured; Step 10: Pour the retaining wall (6) on the second pad (2); Step 11: After the retaining wall (6) reaches the design strength, backfill the outer side with crushed stone to form a filter layer (7). Step 12: Install the cover plate (8) on the upper part of the filter layer (7); Step 13: Fill the gap between the cover plate (8) and the cast-in-place retaining wall (6) with sealant (9).

10. The method for constructing a new channel support structure on a deeply buried silt layer foundation according to claim 7, characterized in that: The concrete retaining wall (6) on the side near the channel slope is as follows from top to bottom: the upper section is a vertical surface, the middle section is a slope, and the lower section is a shoulder extending towards the filter layer (7).

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