Pre-buried pipeline structure under structural raft and construction method
By digging V-shaped grooves under the raft slab of the fire elevator shaft drainage collection puddle, laying sand cushions and laying embedded metal drainage pipes, the problem of foundation damage in the prior art is solved, and higher construction safety and quality stability are achieved.
Patent Information
- Application Number
- CN202510304598.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-04-18
AI Technical Summary
When setting up a fire elevator shaft drainage collection pit, the embedded drainage pipes in the prior art are laid under the structural raft slab, which can easily cause damage to the foundation and pose a quality and safety hazard.
V-shaped grooves are dug in the base layer of the raft, and the bottom of the groove is inspected and pretreated, a thick sand cushion layer is laid, and the embedded metal drainage pipes are laid, and then the concrete is backfilled and water-flow test is carried out to ensure that there is no water leakage.
By burying the pipes under the raft, the damage to the foundation is avoided, the construction safety and quality stability are improved, and the construction cost and complexity are reduced.
Smart Images
Figure CN119843749A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fire-fighting drainage, and in particular to a pre-buried pipeline structure under a structural raft and a construction method. Background Art
[0002] The elevator shaft located at the bottom of the basement, especially the fire elevator shaft, will need to be equipped with fire drainage measures according to the specifications. The usual practice is to set up an elevator shaft drainage sump on the side adjacent to the elevator shaft, reserve a hole or pipe slope towards the sump on the side wall of the elevator shaft, and then use a submersible sewage pump to lift and drain to the outdoor rainwater pipe network.
[0003] Generally, the bottom of an elevator shaft is 1.3-2.5 meters lower than the ground of the building where it is located, and the drainage sump of the elevator shaft is generally 1.2-1.5 meters lower than the elevator shaft. However, due to the architectural layout or aesthetic requirements, the drainage sump of the elevator shaft is often not close to the elevator shaft. The distance between the two is generally within 4-5 meters, and in some cases it is even farther. In this case, it is necessary to pre-bury drainage pipes from the bottom of the elevator shaft to the drainage sump of the elevator shaft at a slope of 0.005-0.010. The height difference between the pipe and the bottom finished surface of the basement is about 1.3-2.6 meters.
[0004] There are two construction methods for reserved drainage pipes. One is to lay them above the structural raft slab, and the other is to lay them below the raft slab. When the reserved pipe is laid above the raft slab, the structural raft slab in the area where the pipe is laid needs to be folded (such as the attached Figure 1 ), which not only increases the amount of foundation pit excavation, but also requires backfilling above the folded plate in the later stage, which is cumbersome and costly to construct; when the pipe is laid under the raft, the soil under the raft is generally hard, and even rocks may appear. In order to lay the pre-buried drainage pipes, the local foundation needs to be excavated and backfilled; although this method is cheaper and easier to construct than the previous method, it is also the current common construction method for reserving drainage pipes, but this method damages the foundation under the raft and poses a quality and safety hazard. Summary of the invention
[0005] The purpose of the present invention is to provide a pre-buried pipeline structure under a structural raft and a construction method, aiming to avoid the pipeline laid under the structural raft from damaging the foundation after excavation, which poses a quality and safety hazard.
[0006] To achieve the above object, in a first aspect, the present invention provides a method for constructing a pre-buried pipeline under a structural raft, comprising the following steps: Digging a V-shaped groove in the foundation layer under the raft slab, and inspecting and pre-treating the V-shaped groove; Digging a trench into the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe; Drain the water from the elevator foundation pit to the elevator shaft, then backfill the V-shaped groove with concrete, and conduct a water flow test. It is qualified if there is no leakage.
[0007] The specific method of digging a V-shaped groove in the foundation layer under the raft slab and detecting and pre-treating the V-shaped groove is as follows: Use the total station to lay out the center line and side line of the V-shaped groove, and calculate the excavation side line and lime spreading line based on the preset slope; Using an excavator to dig in layers along the edge line, adjusting the bucket angle based on a preset slope to form a V-shaped section; Manually clean the loose soil at the bottom of the trench and the slope, trim it to the preset section, check whether the soil at the bottom of the trench is uniform, and compact it to level it.
[0008] Among them, the bottom width of the V-groove is 400 mm, and the preset slope is 1:1 or 1:1.5.
[0009] The specific method of digging a groove into the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe is as follows: Digging a trench to a preset elevation toward the compacted V-shaped groove, compacting the trench and laying a thick sand cushion layer; Prefabricate the embedded metal drainage pipe and lay it from the water collection well to the starting point.
[0010] The specific method of draining water from the elevator foundation pit to the elevator shaft, backfilling the V-shaped groove with concrete, and conducting a water flow test, and the specific method of passing the test if there is no water leakage is as follows: Drain water from the elevator pit to the elevator shaft; Pour concrete symmetrically on both sides of the embedded metal drainage pipe to backfill the V-shaped groove; The pre-buried metal drainage pipe is tested for water flow. It is qualified if there is no leakage after filling with water for 15 minutes and observing for 30 minutes.
[0011] In a second aspect, the present invention further provides a pre-buried pipe structure under a structural raft slab, which is applied to the method for pre-buried pipe structure under a structural raft slab as described in the first aspect above.
[0012] The invention discloses a method for constructing pre-buried pipes under a structural raft slab. The method comprises the following steps: digging a V-shaped groove in a base layer under the raft slab, and inspecting and pre-treating the V-shaped groove; digging a groove in the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe; draining water from an elevator foundation pit to an elevator shaft sump, backfilling the V-shaped groove with concrete, and conducting a water flow test. The pipe is qualified if there is no water leakage. The method digs the V-shaped groove under the raft slab, compacts the foundation, lays a sand layer, trims and reinforces the excavated foundation, and then lays the pre-buried metal drainage pipe in the reinforced foundation and then backfills with C15 plain concrete. Compared with the traditional method of laying pipes under the raft slab, the method additionally compacts the foundation, lays a sand layer, and trims and reinforces the excavated foundation, and has higher safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0014] Figure 1 It is a schematic diagram of the treatment measures for the elevator shaft embedded pipe elevation being lower than the raft slab bottom.
[0015] Figure 2 This is a large-scale drawing of the pre-buried water pipes in the elevator shaft drainage sump.
[0016] Figure 3 This is a schematic diagram of the buried water pipe installation.
[0017] Figure 4 The present invention provides a flow chart of a method for constructing pre-buried pipelines under a structural raft.
[0018] Figure 5 The invention is a flow chart of a specific method of digging a V-shaped groove in a foundation layer under a raft slab, and detecting and pre-treating the V-shaped groove.
[0019] Figure 6 It is a flow chart of a specific method of digging a trench into the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe.
[0020] Figure 7 It is a flowchart of a specific method of draining water from an elevator foundation pit to an elevator shaft, backfilling the V-shaped groove with concrete, and conducting a water flow test, and the test is qualified if there is no water leakage. DETAILED DESCRIPTION
[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0022] See also Figures 1 to 7 , the present invention provides a construction method for pre-buried pipelines under a structural raft, comprising the following steps; S1: digging a V-shaped groove in the foundation layer under the raft slab, and inspecting and pre-treating the V-shaped groove; Specific method: S11 uses a total station to lay out the center line and side line of the V-shaped groove, and calculates the excavation side line and lime spreading line based on the preset slope; In the embodiment of the present invention, a total station or GPS is used to lay out the center line and side line of the V-shaped groove, and control piles are set. The excavation side line is calculated according to the designed slope (such as 1:1, 1:1.5, etc.), and a lime line is spread or a wooden stake is driven to mark it. Secondly, the original ground elevation is measured with a level to determine the excavation depth.
[0023] S12 uses an excavator to excavate in layers along the edge line, and adjusts the angle of the bucket based on a preset slope to form a V-shaped section; In the embodiment of the present invention, an excavator is used to excavate in layers along the set-out edge line from top to bottom, and the bucket angle is adjusted according to the designed slope to initially form a V-shaped section. A protective layer (about 20 cm) is reserved to avoid over-excavation.
[0024] S13 Manually clean the loose soil at the bottom of the trench and the slope, trim it to the preset section, check whether the soil at the bottom of the trench is uniform, and compact it to level it.
[0025] In the embodiment of the present invention, manual finishing is performed. Loose soil at the bottom of the trench and the slope is manually cleaned and trimmed to the designed section. The slope of the slope is checked with a slope gauge to ensure that it meets the requirements. A foundation inspection is performed to check whether the soil at the bottom of the trench is uniform and whether the bearing capacity meets the design requirements. If the base is a soft soil layer, it needs to be replaced with gravel or crushed stone and compacted. Secondly, compaction and leveling are performed. The bottom of the trench is compacted (with a light roller or manual tamping) to ensure flatness.
[0026] S2: digging a trench into the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe; Specific method: S21 excavates a trench to a preset elevation toward the compacted V-shaped groove, compacts the trench, and lays a thick sand cushion layer; In the embodiment of the present invention, the foundation is checked to check whether the soil quality at the bottom of the trench is uniform and whether the bearing capacity meets the design requirements. If the base is a soft soil layer, it needs to be replaced with gravel or crushed stone and compacted. Secondly, compaction and leveling are performed. The bottom of the trench is compacted (with a light roller or manual tamping) to ensure flatness.
[0027] S22 prefabricates a preburied metal drainage pipe and lays the preburied metal drainage pipe from the water collection well to the starting point.
[0028] In the embodiment of the present invention, pipeline prefabrication and installation are performed. The pipeline is cut according to the designed length, and the weld / flange connection is treated with anti-corrosion in advance (such as zinc supplementation of the weld of galvanized pipe). The main pipe is installed first, and is laid from the drainage end point (water collection well) to the starting point to ensure that the slope meets the requirements. A laser level is used to monitor the pipeline elevation in real time, and each section of the pipeline is temporarily fixed after installation. When constructing the pipeline connected by welding, the weld is full and has no pores. After welding, the welding slag is removed and the anti-corrosion layer is applied. When constructing the pipeline connected by flange, the bolts are tightened symmetrically and evenly, and rubber gaskets are added between the flanges for sealing. Finally, the branch pipe and accessories are installed. The branch pipe and the main pipe are connected with an oblique tee or a Y-type tee to reduce water flow resistance. Concrete piers or steel brackets are set at the turning point for reinforcement to prevent the displacement of the pipeline caused by water flow impact; the pipeline is fixed to the bottom steel bar of the raft slab using U-shaped clamps or steel bar welding, with a spacing of ≤2m; the elbows and tees are fixed densely. Rubber sheets are placed between the pipeline and the steel bar to avoid electrochemical corrosion. The welds of galvanized steel pipes and the outer wall of cast iron pipes are painted with epoxy asphalt paint twice, and anti-corrosion tape is used when the burial depth is large. The inner wall of the pipe is coated with cement mortar lining (cast iron pipe) or epoxy resin coating (steel pipe) to prevent internal corrosion.
[0029] S3 drains water from the elevator foundation pit to the elevator shaft, then backfills the V-shaped groove with concrete, and conducts a water flow test. It is qualified if there is no leakage.
[0030] Specific method: S31 drains water from the elevator pit to the elevator shaft; S32 symmetrically pouring concrete from both sides of the embedded metal drainage pipe to backfill the V-shaped groove; In the embodiment of the present invention, concrete is poured symmetrically from both sides of the embedded metal drainage pipe to avoid the displacement of the embedded metal drainage pipe due to unilateral pressure, and then the excavated V-shaped groove is backfilled with C15 plain concrete.
[0031] S33: The embedded metal drainage pipe is tested for water flow, filled with water for 15 minutes, and observed for 30 minutes without leakage, which is qualified.
[0032] In a second aspect, the present invention further provides a pre-buried pipe structure under a structural raft slab, which is applied to the method for pre-buried pipe structure under a structural raft slab as described in the first aspect above.
[0033] The above disclosure is only a preferred embodiment of a pre-buried pipe structure and construction method under a structural raft of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.
Claims
1. A construction method for pre-buried pipelines under a structural raft, characterized in that: The steps include: Digging a V-shaped groove in the foundation layer under the raft slab, and inspecting and pre-treating the V-shaped groove; Digging a trench into the compacted V-shaped groove, laying a thick sand cushion layer, and laying a pre-buried metal drainage pipe; Drain the water from the elevator foundation pit to the elevator shaft, then backfill the V-shaped groove with concrete, and conduct a water flow test. It is qualified if there is no leakage.
2. The method for constructing a pre-buried pipeline under a structural raft as claimed in claim 1, characterized in that: The specific method of digging a V-shaped groove in the foundation layer under the raft slab and detecting and pre-treating the V-shaped groove is as follows: Use the total station to lay out the center line and side line of the V-shaped groove, and calculate the excavation side line and lime spreading line based on the preset slope; Using an excavator to excavate in layers along the edge line, adjusting the bucket angle based on a preset slope to form a V-shaped section; Manually clean the loose soil at the bottom of the trench and the slope, trim it to the preset section, check whether the soil at the bottom of the trench is uniform, and compact it to level it.
3. The method for constructing a pre-buried pipeline under a structural raft as claimed in claim 2, characterized in that ； The bottom width of the V-shaped groove is 400 mm, and the preset slope is 1:1 or 1:1.
5.
4. The method for constructing a pre-buried pipeline under a structural raft as claimed in claim 1, characterized in that: The specific method of digging a groove into the compacted V-shaped groove, laying a thick sand cushion layer, and laying the pre-buried metal drainage pipe is as follows: Digging a trench to a preset elevation toward the compacted V-shaped groove, compacting the trench and laying a thick sand cushion layer; Prefabricate the embedded metal drainage pipe and lay it from the water collection well to the starting point.
5. The method for pre-buried pipe structure under the structural raft as claimed in claim 1, It is characterized by: The specific method of draining water from the elevator foundation pit to the elevator shaft, backfilling the V-shaped groove with concrete, and conducting a water flow test, and the specific method of passing the test if there is no water leakage is as follows: Drain water from the elevator pit to the elevator shaft; Pour concrete symmetrically on both sides of the embedded metal drainage pipe to backfill the V-shaped groove; The pre-buried metal drainage pipe is tested for water flow. It is qualified if there is no leakage after filling with water for 15 minutes and observing for 30 minutes.
6. A pre-buried pipe structure under a structural raft slab, applied to the method for pre-buried pipe structure under a structural raft slab as claimed in any one of claims 1 to 5.