A method for controlling the settlement of a drainage pipe passing through a soft soil layer

Abstract

The present invention relates to the technical field of pipeline settlement control construction, specifically a method for controlling pipeline settlement when a drainage pipeline passes through a soft soil layer. The present invention reinforces the foundation soil of the pipeline bottom by grouting, and the pipeline is encapsulated with concrete with functional natural river sand or recycled machine-made sand to reinforce the strength of the pipeline interface while preventing water seepage at the pipeline interface from eroding the surrounding soil. The top of the pipe uses a reinforced concrete top plate to disperse the traffic load borne by the pipeline. The above solves the quality problems such as pipeline settlement caused by the pipeline passing through a soft soil layer, the increase or even disconnection of the gap at the pipeline interface during and after the construction, and the problem of road surface sinking caused by water erosion and hollowing out the soil around the pipeline interface after the pipeline is put into operation, thereby ensuring the construction quality of the drainage pipeline and the service life and safety of the pipeline and the upper road surface in the later operation.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline settlement control construction, and in particular to a method for controlling pipeline settlement when a drainage pipeline passes through a soft soil layer. Background Art

[0002] Concrete pipes are widely used as one of the main materials for drainage projects, but the weight of concrete pipes is large. Especially after heavy rain, when a large amount of surface water flows into the drainage pipes, it greatly increases the pipe's requirements for the foundation bearing capacity.

[0003] When constructing pipelines through soft soil layers, common grooving construction methods are used. During and after the construction process, the installed pipelines will experience uneven settlement, increased gaps at the pipeline interfaces, and even pipeline disconnection. After the drainage pipeline is put into use, the flowing water will continuously erode and hollow out the soil around the pipeline interface, and even cause the road surface to sink. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies in the prior art, so a method for controlling the settlement of a drainage pipe passing through a soft soil layer is proposed. The soil body of the pipe foundation at the bottom of the pipe is reinforced by grouting. The pipe is encapsulated with concrete containing functional natural river sand or recycled machine-made sand to reinforce the strength of the pipe interface while preventing water from seeping out of the pipe interface and eroding the surrounding soil body. The top of the pipe uses a reinforced concrete top plate to disperse the traffic load borne by the pipe. The above solves the problems of pipe settlement caused by the pipe passing through a soft soil layer, the increase or even disconnection of the gap at the pipe interface during and after the construction, and the problem of road surface sinking caused by water erosion and hollowing out the soil body around the pipe interface after the pipe is put into operation, thereby ensuring the construction quality of the drainage pipe and the service life and safety of the pipe and the upper road surface in the later operation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for controlling the settlement of a drainage pipe passing through a soft soil layer comprises the following steps:

[0007] Step 1: Use compaction grouting to reinforce the soft soil within a depth of 2 meters and a width of 2 meters below the pipeline foundation;

[0008] The grouting pressure is 1.0Mpa, the grouting distance is 1 meter, the slurry contains 2% water glass, and the curing is 7 days after the grouting is completed;

[0009] Step 2: Support and dig trenches to install pipelines;

[0010] Step 3: Use C20 concrete mortar to seal the concrete pipe to the top of the pipe;

[0011] Step 3: Install Φ10 steel mesh on the top of the pipe with a spacing of 300*300, and pour C20 concrete with a thickness of 300mm.

[0012] On the basis of the above scheme, the following improvements are made: functional natural river sand or regenerated machine-made sand is used in the C20 concrete mortar. The method for making functional natural river sand or regenerated machine-made sand comprises the following steps: weighing a certain amount of aggregate, adding it to ethanol, magnetically stirring for 12 hours to evenly disperse the aggregate, adjusting the pH value of the solution to 3.5-4.2 with 1 mol / L hydrochloric acid, and then adding one-quarter to one-third of the amount of aggregate propyltrimethoxysilane and comb-like polymer-polymethacrylate octadecyl ester to the system, and the ratio of propyltrimethoxysilane and comb-like polymer-polymethacrylate octadecyl ester is (2-3): (1.1-1.5). After mixing evenly, the solution is transferred to an insulated stirring tank, the system temperature is controlled to 80°C, and mechanically stirred for 10 hours to finally obtain functional natural river sand or regenerated machine-made sand.

[0013] On the basis of the above scheme, the following improvements are made: in the step 2, a hydrophobic casting liquid is used as a pre-treatment at the pipe joint, and then a water spray film is formed. The preparation process of the hydrophobic casting liquid is as follows: a certain amount of polyvinylidene fluoride powder is dissolved in three to four times the amount of N, N-dimethylacetamide solvent of the polyvinylidene fluoride powder, and mechanically stirred at 60°C for 5 hours to obtain a uniform casting liquid.

[0014] Based on the above solution, the following improvement is made: a support body is installed at the bottom of the steel mesh, and the bottom of the support body is pre-buried inside the compacting grouting mortar and is located near the pipe joint.

[0015] On the basis of the above scheme, the following improvements are made: the support body includes two support monomers symmetrically tied to the steel mesh, each support monomer includes an embedded body, a support body and a connector, the embedded body and the support body are provided with two groups symmetrically distributed on both sides of the connector, the embedded body is embedded in the compaction grouting, the two ends of the support body are respectively connected to the connector and the embedded body, and the two groups of support bodies located on the same support monomer are installed with adjustment ropes, the two adjustment ropes are connected through the adjustment assembly, and the adjustment assembly is provided with two groups located on both sides of the pipeline. The two support bodies are arranged in a bow-shaped structure, so that the strength of the engineering structure is effectively guaranteed, which is suitable for the stable docking of the two pipelines at the interface, and the corresponding pre-treatment of the casting liquid and the subsequent mortar wrapping are performed, so that the coating is good and safe, and will not cause the problem of soil transportation at the later pipeline joints. Two adjusting ropes are used to clamp the ends of the pipeline near the joints. Since the support body is arranged in a bow-shaped structure along the wind direction of the pipeline, the pipeline can be kept in a stable state after being used together. The top of the support body is welded as a whole and tied or welded to the steel mesh in the later stage, which is beneficial to prevent membrane rupture during the pre-treatment of the casting liquid in the later stage, and can also ensure that the pipeline will not deviate to the side in the later stage, thereby preventing water leakage at the pipeline joints from causing soil erosion and causing the pipeline to deviate to the side.

[0016] Based on the above solution, the following improvements are made: the two groups of adjustment components each include two connectors installed on the corresponding adjustment ropes, the connectors are connected by connecting bidirectional screws, and the inner side of the connectors is an arc-shaped structure. The bidirectional screw can keep the adjustment rope stable, and the bidirectional screw pulls the adjustment rope, thereby preventing micro-deviation during pipeline installation and pre-treatment of the casting liquid.

[0017] Based on the above scheme, the following improvements are made: the connector is provided with a rotating body which is adjustable relative to the adjustment rope, a limiting structure is provided on the rotating body, and the inner side of the connector is provided with a rubber wheel which moves along the outer wall of the pipe in both circumferential and axial directions.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention reinforces the foundation soil of the pipe bottom by grouting. The pipe is encapsulated with concrete containing functional natural river sand or recycled machine-made sand to reinforce the strength of the pipe interface and prevent water from seeping out of the pipe interface and eroding the surrounding soil. The top of the pipe is reinforced concrete to disperse the traffic load borne by the pipe. The above solves the quality problems such as pipe settlement caused by the pipe passing through the soft soil layer, the increase of pipe interface gaps and even disconnection during and after the construction, and the problem of road surface sinking caused by water erosion and hollowing out the soil around the pipe interface after the pipe is put into operation, thereby ensuring the construction quality of the drainage pipe and the service life and safety of the pipe and the upper road surface in the later operation.

[0020] 2. The present invention uses propyltrimethoxysilane and comb-like polymer-octadecyl polymethacrylate to functionally modify natural river sand or regenerated machine-made sand, so that during the solidification process of the mortar, calcium hydroxide will also grow along the polymer solid particles, which is conducive to disrupting the oriented growth of calcium hydroxide. It will condense into a film at a temperature higher than its minimum film-forming temperature. The formed film can surround the calcium hydroxide generated by cement hydration and connect it into a whole, which can effectively reduce the adverse effects of calcium hydroxide on the durability of the material. The addition of propyltrimethoxysilane and comb-like polymer-octadecyl polymethacrylate effectively improves the pore structure of the mortar. Due to the morphological effects of propyltrimethoxysilane and comb-like polymer-octadecyl polymethacrylate and its own particularity, it plays a role in cementation, filling, etc., so that the average pore size of the mortar becomes smaller, large pores become small pores, and the uniformity of pore distribution decreases. The comb-like polymer-polyoctadecyl methacrylate allows the aggregate to construct a cactus-like microstructure in the mortar, which can enhance the connection strength and waterproof effect of the mortar and pipe joints, and can better encapsulate the pipe joints.

[0021] 3. The present invention forms a hydrophobic film (similar to a wax film) by using polyvinylidene fluoride powder and N,N-dimethylacetamide to perform hydrophobic treatment on the pipe joint, thereby further improving the encapsulation effect and waterproof effect of the pipe joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0024] Figure 3 for Figure 2 A side view of the middle support body;

[0025] Figure 4 for Figure 2 Schematic diagram of the overall structure of the middle support body;

[0026] Figure 5 for Figure 2 Connection diagram of the middle connector and the two-way bolt. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Example 1: Figure 1As shown, a method for controlling the settlement of a drainage pipe passing through a soft soil layer comprises the following steps:

[0029] Step 1: Use compaction grouting to reinforce the soft soil within a depth of 2 meters and a width of 2 meters below the pipeline foundation;

[0030] The grouting pressure is 1.0Mpa, the grouting distance is 1 meter, the slurry contains 2% water glass, and the curing is 7 days after the grouting is completed;

[0031] Step 2: Support and dig trenches to install pipelines;

[0032] Step 3: Use C20 concrete mortar to seal the concrete pipe to the top of the pipe;

[0033] Step 3: Install Φ10 steel mesh on the top of the pipe with a spacing of 300*300, and pour C20 concrete with a thickness of 300mm.

[0034] The foundation soil of the pipe bottom is reinforced by grouting, and the pipe is encapsulated with concrete to strengthen the strength of the pipe interface while preventing water from seeping out of the pipe interface and eroding the surrounding soil. The top of the pipe is made of reinforced concrete to disperse the traffic load on the pipe. The above solves the problems of pipe settlement caused by the pipe passing through soft soil layers, the increase of gaps in the pipe interface during and after construction, and even disconnection, as well as the problem of road subsidence caused by water erosion and hollowing out the soil around the pipe interface after the pipe is put into operation, ensuring the construction quality of the drainage pipe and the service life and safety of the pipe and the upper road surface in the later operation.

[0035] On the basis of the above embodiment, the following improvements are made: functional natural river sand or regenerated machine-made sand is used in the C20 concrete mortar, and the method for making functional natural river sand or regenerated machine-made sand is as follows: a certain amount of aggregate is weighed, added to ethanol, and magnetically stirred for 12 hours to evenly disperse the aggregate, and the pH value of the solution is adjusted to 3.5-4.2 with 1 mol / L hydrochloric acid, and then one-quarter to one-third of the amount of aggregate propyltrimethoxysilane and comb polymer-polymethacrylate octadecyl ester are added to the system, preferably one-quarter, propyltrimethoxysilane and comb polymer-polymethacrylate octadecyl ester are mixed in a ratio of 2.4:1.3, and then the solution is transferred to an insulated stirring tank, the system temperature is controlled to 80°C, and mechanical stirring is performed for 10 hours to finally obtain functional natural river sand or regenerated machine-made sand.

[0036] By using propyl trimethoxysilane and comb polymer-octadecyl polymethacrylate to modify the function of natural river sand or regenerated machine-made sand, calcium hydroxide will also grow along the polymer solid particles during the solidification process of mortar, which is conducive to disrupting the oriented growth of calcium hydroxide. It will condense into a film at a temperature higher than its minimum film-forming temperature. The formed film can surround the calcium hydroxide generated by cement hydration and connect it into a whole, which can effectively reduce the adverse effects of calcium hydroxide on the durability of the material. The addition of propyl trimethoxysilane and comb polymer-octadecyl polymethacrylate effectively improves the pore structure of the mortar. Due to the morphological effect of propyl trimethoxysilane and comb polymer-octadecyl polymethacrylate and its own particularity, it plays a role in cementation and filling, making the average pore size of the mortar smaller, large pores become small pores, and the uniformity of pore distribution decreases. Comb polymer-octadecyl polymethacrylate allows aggregates to construct a cactus-like microstructure in the mortar, which can better encapsulate its pipe joints.

[0037] Based on the above embodiment, the following improvements are made: in step 2, a hydrophobic casting liquid is used as a pre-treatment at the pipe joint, and then a water spray film is formed. The preparation process of the hydrophobic casting liquid is as follows: a certain amount of polyvinylidene fluoride powder is dissolved in three to four times the amount of N, N-dimethylacetamide solvent of the polyvinylidene fluoride powder, preferably 3 times, and mechanically stirred at 60°C for 5 hours to obtain a uniform casting liquid. The pipe joint is hydrophobically treated by forming a hydrophobic film with polyvinylidene fluoride powder and N, N-dimethylacetamide, thereby further improving the encapsulation effect and waterproof effect of the pipe joint.

[0038] Based on the above embodiment, the following improvements are made: Figures 2 to 5As shown, a support body 10 is installed at the bottom of the steel mesh, and the bottom of the support body 10 is embedded in the compaction grouting mortar and is located near the pipe joint. The support body 10 includes two support monomers 11 symmetrically tied to the steel mesh, and each support monomer 11 includes an embedded portion 111, a support portion 112 and a connecting portion 113. The embedded portion 111 and the support portion 112 are provided with two groups symmetrically distributed on both sides of the connecting portion 113. The embedded portion 111 is embedded in the compaction grouting, and the two ends of the support portion 112 are respectively connected to the connecting portion 113 and the embedded portion 111 as a whole. Adjustment ropes 114 are installed on the two groups of support portions 112 located on the same support monomer 11, and the two adjustment ropes 114 are connected through an adjustment component and the adjustment component is provided with two groups located on both sides of the pipeline. The two groups of adjustment components each include two connectors 115 respectively mounted on the corresponding adjustment ropes 114. The connectors 115 are connected by connecting bidirectional screws 116. The inner side of the connectors 115 is an arc-shaped structure. The bidirectional screws 116 can keep the adjustment ropes 114 stable. The bidirectional screws 115 pull the adjustment ropes 114 to prevent micro-deviation during pipeline installation and pre-treatment of the casting liquid. The two adjustment ropes 114 are arranged crosswise.

[0039] The two supports 10 are arranged in a bow-shaped structure, so that the strength of the engineering structure is effectively guaranteed, which is suitable for the stable docking of the two pipes at the interface, and the corresponding pre-treatment of the casting liquid and the subsequent mortar wrapping are carried out, so that the coating is good and safe, and there will be no problem of soil transportation at the joints of the pipes in the later stage. The two adjustment ropes 114 are respectively clamped to the ends of the pipes near the joints. Since the support body 10 is arranged in a bow-shaped structure along the wind direction of the pipe, the pipe can be kept in a stable state after being used in combination, and the top of the support body 10 is selected to be welded as a whole and tied or welded with the steel mesh in the later stage, which is conducive to the pre-treatment of the casting liquid in the later stage without membrane rupture, and it can also ensure that the pipe will not deviate later, thereby preventing water leakage at the pipe joints from causing soil erosion and causing pipe lateral deviation.

[0040] Based on the above solution, the following improvements are made: the connector 115 is provided with a rotating body 117 whose position is adjustable relative to the adjusting rope 114, and the inner side of the connector 117 is provided with a rubber wheel 118 which moves along the outer wall of the pipe in both circumferential and axial directions. When in use, all the connectors 117 can be placed at the bottom of the pipeline. First, the pipeline can be supported and separated from the support at the bottom, which is convenient for pre-treatment of the casting liquid at its port position. After the treatment is completed, the connector 117 is slowly moved along the length direction of the pipeline outer wall and the adjusting rope 114, and the connectors 115 on both sides of the pipeline joint move at the same time until the adjusting rope 114 at the bottom is clamped at the bottom of the outer wall of the pipeline, and finally a cross and stable support structure is formed. The height of the pipeline will not change during the process. Finally, all the connectors 117 are locked by the matching nuts on the two-way screw 116, and the outside of the pipeline is wrapped with mortar for anti-leakage and water treatment. The pipeline is clamped and pulled by two adjusting ropes 114, so that axial movement will not occur when the pipeline is used later; at the same time, the pipeline is pressurized left and right by the connector 115 and the rubber wheel 118, so that the end is treated with anti-deviation to prevent water leakage at the end joint.

[0041] The above is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. The replacement may be a replacement of a part of the structure, device, method step, or a complete technical solution. Any equivalent replacement or change according to the technical solution and the inventive concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A method for controlling the settlement of a drainage pipe when it passes through a soft soil layer, characterized in that: The following steps are involved: Step 1: Use compaction grouting to reinforce the soft soil within a depth of 2 meters and a width of 2 meters below the pipeline foundation; The grouting pressure is 1.0Mpa, the grouting interval is 1 meter, the slurry contains 2% water glass, and the curing is 7 days after the grouting is completed; Step 2: Support and dig trenches to install pipelines; Step 3: Use C20 concrete mortar to seal the concrete pipe to the top of the pipe; Step 3: Install Φ10 steel mesh on the top of the pipe with a spacing of 300*300, and pour C20 concrete with a thickness of 300mm; Functional natural river sand or regenerated machine-made sand is used in the C20 concrete mortar. The method for preparing the functional natural river sand or regenerated machine-made sand comprises the following steps: weighing a certain amount of aggregate, adding the aggregate to ethanol, magnetically stirring for 12 hours to evenly disperse the aggregate, adjusting the pH value of the solution to 3.5-4.2 with 1 mol / L hydrochloric acid, and then adding propyltrimethoxysilane and comb-like polymer-polymethacrylate octadecyl ester in an amount of one-quarter to one-third of the aggregate to the system, wherein the ratio of propyltrimethoxysilane to comb-like polymer-polymethacrylate octadecyl ester is (2-3): (1.1-1.5). After mixing evenly, the solution is transferred to an insulated stirring tank, the system temperature is controlled to 80°C, mechanically stirred for 10 hours, and finally the functional natural river sand or regenerated machine-made sand is prepared.

2. A method for controlling pipe settlement when a drainage pipe passes through a soft soil layer according to claim 1, characterized in that: In the step 2, a hydrophobic casting liquid is used as a pre-treatment at the pipe joint, and then a water spray film is formed. The preparation process of the hydrophobic casting liquid is as follows: a certain amount of polyvinylidene fluoride powder is dissolved in three to four times the amount of N, N-dimethylacetamide solvent of the polyvinylidene fluoride powder, and mechanically stirred at 60° C. for 5 hours to obtain a uniform casting liquid.

3. A method for controlling pipe settlement when a drainage pipe passes through a soft soil layer according to claim 1, characterized in that: A support body is installed at the bottom of the steel mesh, and the bottom of the support body is pre-buried in the compacting grouting mortar and is located near the pipe joint.

4. A method for controlling pipe settlement when a drainage pipe passes through a soft soil layer according to claim 3, characterized in that: The support body includes two support monomers symmetrically tied to the steel mesh, each support monomer includes an embedded body, a support body and a connecting body, the embedded body and the support body are provided with two groups symmetrically distributed on both sides of the connecting body, the embedded body is embedded in the compaction grouting, the two ends of the support body are respectively connected to the connecting body and the embedded body as a whole, and the two groups of support bodies located on the same support monomer are installed with adjustment ropes, the two adjustment ropes are connected by an adjustment component, and the adjustment component is provided with two groups located on both sides of the pipeline.

5. A method for controlling pipe settlement when a drainage pipe passes through a soft soil layer according to claim 4, characterized in that: The two groups of adjustment components each include two connectors respectively mounted on corresponding adjustment ropes, the connectors are connected by connecting bidirectional screws, and the inner side of the connector is an arc-shaped structure.

6. A method for controlling pipe settlement when a drainage pipe passes through a soft soil layer according to claim 5, characterized in that: The connector is provided with a rotating body which is adjustable relative to the position of the adjusting rope, a limiting structure is provided on the rotating body, and a rubber wheel which moves along the outer wall of the pipeline in both the circumferential direction and the axial direction is provided on the inner side of the connector.

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