A construction method for removing obstacles with a full-rotation drilling rig and backfilling with solidified soil

Abstract

The present invention discloses a construction method for using a full-rotation drilling rig to remove obstacles and cooperate with solidified soil backfilling, comprising the following steps: Step 1: Determine the underground pipeline section that affects the construction of the retaining structure, and block both ends of the underground pipeline impact section; Step 2: Use a full-rotation drilling rig to drill at the location of the retaining pile to be constructed, and the steel casing of the full-rotation drilling rig covers the cross-sectional area of ​​the retaining pile to be constructed; Step 3: After drilling below the underground pipeline and reaching the designed position, fill the steel casing with premixed fluidized solidified soil, and the solidified soil is first filled into the underground pipeline until the underground pipeline impact section is filled with solidified soil, and then continue to fill the solidified soil to the ground; Cut the remaining underground pipelines and fill with solidified soil in sequence according to the above steps. This application has little disturbance to the surrounding soil, can meet the synchronous construction of adjacent buildings, and save construction time.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit support, and in particular to a construction method for using a full-rotation drilling rig to remove obstacles and cooperate with solidified soil backfilling. Background Art

[0002] With the development of urban construction, especially urban reconstruction and new construction of underground spaces, the problem of removing underground obstacles is often encountered. Common underground obstacles include underground pipelines, building foundations, etc.

[0003] At present, a certain pipeline corridor project A is under construction, and its south side is adjacent to the existing operating subway project B. Project A is within the construction range of the protection zone of the operating subway project B, and the north and east sides of Project A are respectively adjacent to the foundation pits of the ongoing projects C and D. During the construction of pipeline corridor project A, the location of the retaining piles and ground-connected wall structures encountered existing abandoned pipelines and tunnels. The pipeline diameter is 2.2m, the tunnel clearance is 2.0m×2.3m, and the depth is more than 5m. Due to the above-mentioned surrounding environment constraints, it does not have the conditions for large-scale excavation and sloping for conventional construction.

[0004] In order to ensure the safety and stability of the operating project B, ensure the complete stability of the adjacent C and D foundation pit spaces, and meet the closure requirements for the construction of the retaining structure of project A, the current conventional practice is to wait for the completion of the construction of the project C and D foundation pit structures before excavating the project A foundation pit, which will cause the construction period to be delayed by at least two months, which is inconsistent with the construction schedule.

[0005] The existing Chinese invention patent application with application number 202410512660.1 discloses a full-rotation casing drilling rig pile extraction construction process, which relates to the field of pile foundation removal construction technology. It includes the following steps: construction preparation, pile position setting, laying of working platform, drilling rig in place, casing pressing down, rotating and twisting off old piles, pulling out the twisted and broken old piles, repeating casing pressing down ~ pulling out the twisted and broken old piles, thoroughly clearing obstacles, and backfilling pile holes. The present invention has high construction safety, and the casing follows the wall throughout the process. The casing is pressed in by rotation, which has little disturbance to the surrounding soil, and can be constructed close to existing buildings and structures; it is very suitable for municipal engineering and is the trend of urban construction development; compared with the pile punching method and water flushing method, the present invention has high speed, high work efficiency, low noise, and less waste; it adopts mechanized construction, the casing follows up throughout the process, and the punching and grabbing drill cooperates to grab the soil or pile section in the casing, and the pile section can be repeatedly grabbed in the casing, and the obstacle clearance situation can be observed intuitively; after the obstacle clearance, the pile hole backfill is easy to be dense, ensuring the safety of the later construction.

[0006] The above scheme discloses a construction method for static cutting using a full-rotation drilling rig, which has little disturbance on the surrounding soil and can be constructed close to existing buildings and structures. The above method is only suitable for clearing specific obstacles in a small area. As for how to clear large-scale, through-going underground pipeline obstacles and ensure dense backfill, the above scheme is no longer applicable. Currently, there is an urgent need for a method for clearing underground pipeline obstacles. Summary of the invention

[0007] The present invention provides a construction method for using a full-rotation drilling rig to clear obstacles and cooperate with solidified soil backfilling to solve the above problems.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] The invention discloses a construction method for removing obstacles with a full-rotation drilling rig and backfilling with solidified soil, comprising the following steps:

[0010] Step 1: Determine the underground pipeline section that affects the construction of the retaining structure, and seal both ends of the underground pipeline affected section;

[0011] Step 2: Locate the position of the retaining piles to be constructed within the influence area of ​​the underground pipeline, and use a full-rotation drill to drill at the position of the retaining piles to be constructed. The steel casing of the full-rotation drill covers the cross-sectional area of ​​the retaining piles to be constructed; use the full-rotation drill to drive the steel casing to rotate, cut, drill and sink into the soil, cut the underground pipeline within the range of the steel casing, and remove the soil inside the steel casing and the cut underground pipeline;

[0012] Step 3: After drilling below the underground pipeline and reaching the designed position, pull out the steel casing upward to the top of the underground pipeline, and fill the steel casing with premixed fluidized solidified soil. The solidified soil is first filled into the underground pipeline until the underground pipeline influence area is filled with solidified soil. After the solidified soil is filled to the top of the underground pipeline, pull out the steel casing while filling the solidified soil until the solidified soil is filled to the ground. Cut the remaining underground pipelines in sequence according to the above steps, and fill the solidified soil to the ground by pulling out the steel casing while filling the solidified soil.

[0013] The present invention provides a construction method for removing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Further, in step 1, the underground pipeline is blocked by means of pile foundation bite.

[0014] The invention discloses a construction method for removing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Furthermore, the pile foundation drilling hole is drilled with the full-rotation drilling rig.

[0015] The present invention provides a construction method for clearing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Further, the position of each pile foundation is located and laid out, the bottom end of the pile foundation is located below the underground pipeline, and the construction is carried out in sequence according to the skip hole method. The steel casing is rotated into the soil by the full-rotation drilling rig, and the underground pipeline within the pile foundation range is cut, the soil in the steel casing and the cut underground pipeline are cleared, and early-strength concrete is poured into the steel casing to the ground elevation. After the concrete is initially set, the steel casing is slowly pulled out to carry out the construction of the next pile foundation.

[0016] The invention discloses a construction method for removing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Furthermore, after the engaged pile foundation steel casing is pulled out, a filler is arranged at the gap left by the steel casing on the adjacent pile foundation for plugging.

[0017] The invention discloses a construction method for clearing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Furthermore, after the engaged pile foundation steel casing is pulled out, steel bars are embedded in the gaps left by the steel casing on adjacent pile foundations, the embedding depth is the same as the depth of the pile foundation, a filling area is formed between the steel bars, a filling pipe is inserted into the filling area, and foam glue is filled into the filling area through the filling pipe from bottom to top to seal it.

[0018] The present invention provides a construction method for clearing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Further, in step 2, the center position of the retaining piles within the influence range of the underground pipeline is located and laid out, the center position of the steel casing is consistent with the center position of the retaining piles, and the diameter of the steel casing is larger than the diameter of the retaining piles.

[0019] The present invention provides a construction method for using a full-rotation drill to clear obstacles and cooperate with solidified soil backfilling. Further, the strength of the solidified soil is controlled within a range of 0.8-1.8 MPa.

[0020] The present invention discloses a construction method for removing obstacles with a full-rotation drilling rig and cooperating with solidified soil backfilling. Furthermore, the solidified soil ratio is: curing agent: clay: water = 200:1800:353.

[0021] The present invention provides a construction method for using a full-rotation drilling rig to clear obstacles and cooperate with solidified soil backfilling. Further, the slump of the premixed fluidized solidified soil is 180-220 mm.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. By using a full-rotation drilling rig to perform static cutting of underground pipelines, the surrounding soil is disturbed less, which can ensure the safety and stability of the obstacles removed near multiple existing foundation pits, realize the safe and stable synchronous construction of the A, C, and D foundation pits, and at the same time ensure the safety and stability of the operating project B, saving at least two months of construction time;

[0024] 2. Select specific fluidized solidified soil for backfilling. On the one hand, the fluidized solidified soil has a certain strength to meet the compaction and stability of the stratum and avoid the collapse of the hole during the subsequent retaining pile construction. On the other hand, the strength of the fluidized solidified soil is controlled within a certain range to meet the requirements of the subsequent retaining pile drilling.

[0025] 3. Use interlocking pile foundation to block both ends of the underground pipeline impact zone, divide the large-scale, through-going underground pipeline obstacles into sections, and then remove and backfill the obstacles in the impact zone to ensure the density of the backfill in the underground pipeline;

[0026] 4. Filling the gaps between pile foundations with foam glue can prevent the subsequent flow of fluidized solidified soil. In addition, by inserting steel bars into the gaps, the foam glue is restricted, which makes it easier to determine and control the lifting speed of the filling pipe and ensure that the gaps are filled densely;

[0027] 5. The strength of the solidified soil is controlled at 0.8-1.8MPa, and the ratio is: curing agent: clay: water = 200:1800:353. The slump of the premixed fluidized solidified soil is 200mm. By controlling the strength, ratio and slump of the solidified soil, on the one hand, the fluidized solidified soil has a certain strength to meet the compaction and stability of the stratum and avoid the collapse of the subsequent retaining pile construction. On the other hand, the strength of the fluidized solidified soil is controlled within a certain range to meet the subsequent retaining pile drilling and ensure that the underground pipeline influence area can be filled with dense solidified soil to meet the construction conditions of the retaining structure.

[0028] The present invention will be further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a schematic diagram of the pile foundation interlocking structure of the present invention.

[0031] Reference numerals:

[0032] 1. Underground pipelines; 2. Pile foundations; 3. Steel bars; 4. Foam; 5. Retaining piles. DETAILED DESCRIPTION

[0033] like Figure 1-Figure 2 As shown, the present invention discloses a construction method for removing obstacles with a full-rotation drilling rig and backfilling with solidified soil, comprising the following steps:

[0034] Step 1: Determine the underground pipeline section that affects the construction of the retaining structure, and seal both ends of the underground pipeline affected section. The sealing is carried out by pile foundation bite. In the embodiment of the present application, the pile foundation bite length is 0.3m.

[0035] The specific steps of plugging are: positioning and laying out the position of each pile foundation, the bottom end of the pile foundation is located below the underground pipeline, and construction is carried out in sequence according to the skipping hole method. The steel casing is rotated into the soil by a full-rotation drilling rig, and the underground pipeline within the pile foundation range is cut, the soil in the steel casing and the cut underground pipeline are cleared, and early-strength concrete is poured into the steel casing to the ground elevation. After the concrete is initially set, the steel casing is slowly pulled out to carry out the construction of the next pile foundation. In the embodiment of the present application, C15 concrete is selected as the early-strength concrete, and the initial setting time is 1-2 hours.

[0036] After the interlocking steel casing of the pile foundation is pulled out, steel bars are embedded in the gaps left by the steel casing on the adjacent pile foundations. The embedding depth is the same as the depth of the pile foundation, and a filling area is formed between the steel bars, wherein the spacing between the steel bars should be controlled at 200mm. A filling tube is inserted into the filling area, and foam glue is filled into the filling area through the filling tube from bottom to top for sealing. Filling the gaps between the pile foundations with foam glue can prevent subsequent outflow of fluidized solidified soil. In addition, by inserting steel bars in the gaps, the foam glue is restricted, which makes it easier to determine and control the lifting speed of the filling tube to ensure that the gaps are densely filled.

[0037] Step 2: After the two ends of the underground pipeline impact zone are sealed, locate and lay out the center of the retaining piles within the underground pipeline impact zone. The center of the steel casing is consistent with the center of the retaining piles, and the diameter of the steel casing is larger than the diameter of the retaining piles. The retaining piles are drilled within the range of the steel casing piles.

[0038] A full-rotation drilling rig is used to drive the steel casing to rotate and cut, drill into the soil, and cut the underground pipeline within the range of the steel casing. While the steel casing is gradually pressed in, the soil inside the steel casing and the cut underground pipeline are cleared. After the steel casing is drilled below the underground pipeline, drilling is stopped, and the steel casing is pulled out upward to above the underground pipeline, and fluidized solidified soil is filled into the steel casing. The fluidized solidified soil is first filled into the underground pipeline until the underground pipeline influence area is filled with fluidized solidified soil. After the fluidized solidified soil is filled to above the underground pipeline, the steel casing is pulled up while filling the solidified soil until the solidified soil fills the ground.

[0039] Cut the remaining underground pipelines in sequence according to the above steps, and fill the solidified soil to the ground by pulling out the steel casing while filling the solidified soil.

[0040] After the underground pipeline is cleared, the obstacle hole needs to be backfilled. Since the conditions for the construction of the retaining structure need to be met in the later stage, the obstacle hole needs to be dense. In addition, retaining piles need to be set up at the obstacle hole in the later stage. The selection of backfill material is very important. The backfill material needs to have a certain strength to meet the density and stability of the stratum to avoid collapse during the subsequent retaining pile construction. However, the strength of the backfill material should not be too large, otherwise it will affect the drilling of the retaining pile into the hole. Therefore, the backfill material of this application uses fluidized solidified soil. The fluidity of the fluidized solidified soil can fill all the gaps in narrow spaces and special-shaped structure spaces densely, and because of its It has the characteristics of self-compactness, and does not require large-scale compaction and rolling equipment during construction, which greatly reduces the impact of the construction team on the structural layer; the strength of the solidified soil is controlled at 0.8-1.8MPa, and the ratio is: solidifying agent: clay: water = 200:1800:353, the slump of the premixed fluidized solidified soil is 180-220mm, preferably 200mm, and the solidifying agent is cement, fly ash, CaO inorganic hydraulic cementitious material; at the same time, the fluidized setting of the solidified soil, combined with the pile foundations at both ends of the underground pipeline, fills the affected section of the underground pipeline densely to ensure the stability of the subsequent enclosure structure construction.

[0041] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A construction method for removing obstacles with a full-rotation drilling rig and backfilling with solidified soil, characterized in that: The following steps are involved: Step 1: Determine the underground pipeline section that affects the construction of the retaining structure, and seal both ends of the underground pipeline affected section; The underground pipeline is blocked by the pile foundation bite method. The pile foundation drilling is carried out by a full-revolving drilling rig to locate and lay out the position of each pile foundation. The bottom of the pile foundation is located below the underground pipeline. The construction is carried out in sequence according to the skipping hole method. The steel casing is rotated into the soil by the full-revolving drilling rig, and the underground pipeline within the pile foundation range is cut. The soil in the steel casing and the cut underground pipeline are removed, and early-strength concrete is poured into the steel casing to the ground elevation. After the concrete is initially set, the steel casing is slowly pulled out to carry out the construction of the next pile foundation. After the bite pile foundation steel casing is pulled out, steel bars are embedded in the gap left by the steel casing on the adjacent pile foundation. The embedding depth is the same as the depth of the pile foundation. A filling area is formed between the steel bars. A filling pipe is inserted into the filling area. The filling area is filled with foam glue from bottom to top through the filling pipe to block it. Step 2: Locate the position of the retaining pile to be constructed within the influence range of the underground pipeline, and use a full-rotation drilling rig to drill at the position of the retaining pile to be constructed. The steel casing of the full-rotation drilling rig covers the cross-sectional area of ​​the retaining pile to be constructed; A full rotary drill is used to drive the steel casing to rotate and cut the drill into the soil, cut the underground pipeline within the range of the steel casing, and remove the soil inside the steel casing and the cut underground pipeline; Step 3: After drilling below the underground pipeline and reaching the designed position, pull out the steel casing upward to the top of the underground pipeline, and fill the steel casing with premixed fluidized solidified soil. The solidified soil is first filled into the underground pipeline until the underground pipeline influence area is filled with solidified soil. After the solidified soil is filled to the top of the underground pipeline, pull out the steel casing while filling the solidified soil until the solidified soil is filled to the ground. Cut the remaining underground pipelines in sequence according to the above steps, and fill the solidified soil to the ground by pulling out the steel casing while filling the solidified soil.

2. A construction method for removing obstacles with a full-rotation drilling rig and backfilling with solidified soil according to claim 1, characterized in that: In step 2, the center position of the retaining piles within the influence range of the underground pipeline is located and laid out, the center position of the steel casing is consistent with the center position of the retaining piles, and the diameter of the steel casing is larger than the diameter of the retaining piles.

3. The construction method of using a full-rotation drilling rig to clear obstacles and backfill with solidified soil according to claim 1, characterized in that: The strength of the solidified soil is controlled at 0.8-1.8 MPa.

4. The construction method of using a full-rotation drilling rig to clear obstacles and backfill with solidified soil according to claim 1, characterized in that: The solidifying soil ratio is: solidifying agent: clay: water = 200:1800:

353.

5. The construction method of using a full-rotation drilling rig to clear obstacles and backfill with solidified soil according to claim 1, characterized in that: The slump of the premixed fluidized solidified soil is 180-220 mm.

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