Construction method for removing reinforced concrete pipe piles in soft soil stratum

Abstract

The invention discloses a construction method for removing a reinforced concrete pipe pile in a soft soil stratum. The construction method comprises the steps that S1, a reinforced concrete plate is crushed and excavated; s2, the crest elevation and pile center coordinates of the cover plate are accurately collected; s3, backfilling and leveling the field; s4, a first section of steel sleeve is pressed into the rotary drilling rig; s5, the auger bit rotates and presses down to break the pile body and discharge muck; s6, the rotary drilling rig is pressed into the steel sleeve in a segmented mode, and segmented breaking construction of the reinforced concrete pipe pile is completed in sequence; s7, the rotary drilling rig drives the cutting tooth drill bit to rotate and move downwards to enter the bottom of the tail section of steel casing for bottom cleaning and slag fishing; s8, the punching grab bucket punches and grabs the remaining pile head at the bottom of the reinforced concrete pipe pile; and S9, the holes are backfilled with backfill materials, and meanwhile all the sections of steel sleeves are sequentially pulled out. The whole reinforced concrete pipe pile can be rapidly, efficiently and completely removed, the safety is good, the construction efficiency is high, the construction cost for removing the multiple reinforced concrete pipe piles is remarkably reduced, and the construction quality is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of building foundation construction, and more specifically to a construction method for removing prefabricated reinforced concrete pipe piles in soft soil layers. Background Art

[0002] Soft soil includes soft clay, silty soil, peaty soil and peat, etc., which contain large amount of natural water, high compressibility, low bearing capacity and very low shear strength. Before constructing various types of buildings on soft soil, it is necessary to prefabricate reinforced concrete pile groups in the soft soil to prevent the buildings built on the soft soil from settling. When new buildings need to be rebuilt at the original location due to various factors, new construction activities often conflict with existing reinforced concrete piles underground, and sometimes even large groups of piles conflict. The existing method for removing prefabricated reinforced concrete piles is as follows: first, the soil layer is excavated to expose the head of the reinforced concrete pile, and then the corresponding mechanical equipment is used to loosen the soil around the reinforced concrete pile and the pile body to reduce the friction resistance during extraction, and then the lifting equipment is used to lift the reinforced concrete pile. Since this method cannot determine the lifting force required to pull out the reinforced concrete pile, it is impossible to select the lifting equipment, the construction risk is relatively large, and it is easy to break the pile during construction and the entire reinforced concrete pile cannot be removed. Soft soil is generally clay soil with a high natural water content. The method of driving in steel casing and injecting high-pressure water into the steel casing to liquefy the soft soil, thereby reducing the friction resistance when the reinforced concrete piles are pulled out, will not be effective. The above problems need to be solved urgently. Summary of the invention

[0003] The purpose of the invention is to provide a construction method for removing reinforced concrete pipe piles in soft soil strata safely, quickly, economically and efficiently.

[0004] The present invention is achieved through the following technical solutions:

[0005] A construction method for removing reinforced concrete pipe piles in soft soil strata comprises the following steps:

[0006] S1. First, use the excavator bucket to remove the soil layer on the upper side of the cast-in-place reinforced concrete slab, then use the excavator to use a breaker hammer to break the cast-in-place reinforced concrete slab, and then use the excavator bucket to remove the reinforced concrete fragments until the cover plate on the top of each reinforced concrete pipe pile is completely exposed;

[0007] S2. Use a total station or other measuring instruments to accurately collect the top elevation of the cover plate and the coordinates of the pile center;

[0008] S3. Use an excavator to fill the backfill material into the excavated pit and level the site;

[0009] S4, after the rotary drilling rig is in place, the drill frame is located directly above a reinforced concrete pipe pile in the construction area, the center position of the steel casing is determined according to the pile center coordinates of the reinforced concrete pipe pile measured in step S2, and the rotary drilling rig presses the first section of the steel casing;

[0010] S5, after replacing the spiral drill bit of the rotary drilling rig, driving the spiral drill bit to rotate and press down along the pile center axis of the reinforced concrete pipe pile to break the pile body, and at the same time discharge the slag soil;

[0011] S6, the rotary drilling rig is pressed into the second section of the steel casing, and step S5 is repeated to complete the breaking and external discharge of the pile body in the second section of the steel casing; and so on, the segmented breaking construction of the reinforced concrete pipe pile is completed in sequence, and the remaining pile head including the pile shoe at the bottom of the reinforced concrete pipe pile is not crushed;

[0012] S7. After the pick drill bit is replaced in the rotary drilling rig, the pick drill bit is driven to rotate and move downward into the bottom of the last section of the steel casing to clean the bottom and remove the slag;

[0013] S8. Use a crawler crane to grab the remaining pile head at the bottom of the reinforced concrete pipe pile through a punching grab bucket;

[0014] S9. Use backfill material to backfill the hole until it is level with the ground. At the same time, pull out each section of the steel casing from top to bottom.

[0015] The purpose of the present invention can be further achieved by the following technical measures.

[0016] Furthermore, in step S4, the diameter of the steel casing is Φ700-800 mm, and the gap between the inner hole of the steel casing and the outer circle of the pulled out reinforced concrete pipe pile is uniform.

[0017] Furthermore, in step S5, the bottom of the drill bit after the spiral drill bit moves down to a position higher than the bottom of the steel casing, and the difference between the two is H1 = 50-100 cm.

[0018] Furthermore, in step S8, the height H2 of the remaining pile head is 100-250 cm.

[0019] Furthermore, in step S9, when the backfill material is used to backfill the hole and when each section of the steel casing is pulled out in sequence, the distance H3 between the top surface of the backfill material and the bottom of the steel casing still remaining underground is greater than 2 m.

[0020] Furthermore, in step S9, the backfill material includes original soil mixed with lime, fluidized solidified soil excavated by a shield machine, C10-C15 low-grade concrete and M10-M15 low-grade mortar.

[0021] The present invention accurately locates the pile center position of the reinforced concrete pipe pile by collecting the pile top elevation and pile center coordinate data, and then uses a rotary drilling rig to drive a steel sleeve and a spiral drill bit to break and remove the reinforced concrete pipe pile section by section in the steel sleeve enclosure, and finally uses a stamping grab to remove the remaining pile body and pile shoe. The entire reinforced concrete pipe pile can be quickly and efficiently removed, with good safety and high construction efficiency, and the construction cost of removing multiple reinforced concrete pipe piles is significantly reduced. The adaptability of the present invention is also improved by the ability to select a variety of backfill materials, which significantly improves the construction quality. The driving depth of the steel sleeve and the breaking length of the reinforced concrete pipe pile are determined according to needs, and the step of using the stamping grab to punch and grab the remaining pile head at the bottom of the reinforced concrete pipe pile can also be omitted, which has good flexibility. The present invention can quickly break the steel bars and prestressed steel strands in the pile, and the end plate of the pile head can also be smoothly destroyed and discharged together with the slag. The efficiency of breaking and removing slag is very high.

[0022] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The schematic diagram of the reinforced concrete pipe pile in the soft soil layer that needs to be broken;

[0024] Figure 2 Schematic diagram of using a spiral drill bit to break and remove slag from the pile after pressing in the steel casing;

[0025] Figure 3 A schematic diagram of replacing a pick drill bit to clean the bottom and remove slag;

[0026] Figure 4 This is a schematic diagram of using a punching grab to grab the remaining pile head;

[0027] Figure 5 Schematic diagram of backfill construction and steel sleeve removal operations. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, the reinforced concrete pipe pile 10 to be broken is located in the soft soil layer 20 and is located at the lower side of the cast-in-place reinforced concrete slab 30 under the ground surface 201. It is composed of a cover plate 101, a pile body 102 and a pile shoe 103 fixedly connected from top to bottom. For ease of expression, it is assumed that the reinforced concrete pipe pile 10 of this embodiment includes two sections of pile body 102 connected up and down. The reinforced concrete pipe pile 10 that can be broken using the present invention is not limited to two sections of pile body 102, and can also be used to break multiple sections of pile body 102 connected up and down.

[0030] like Figure 2 to Figure 5As shown, a construction method for removing reinforced concrete pipe piles in soft soil strata comprises the following steps:

[0031] S1. First, use the excavator bucket to remove the soil layer 202 on the upper side of the cast-in-place reinforced concrete slab 30, then use the excavator to use a breaker hammer to break the cast-in-place reinforced concrete slab 30, and then use the excavator bucket to remove the reinforced concrete fragments until the cover plate 101 at the top of each reinforced concrete pipe pile 10 is completely exposed.

[0032] S2. Use a total station or other measuring instruments to accurately collect the top elevation and pile center coordinates of the cover plate 101;

[0033] S3. Use an excavator to fill the backfill material into the excavated pit and level the site.

[0034] S4. After the rotary drilling rig is in place, the drill frame is located directly above a reinforced concrete pipe pile 10 in the construction area. The center position of the steel casing 1 is determined according to the pile center coordinates of the reinforced concrete pipe pile 10 measured in step S2, and the rotary drilling rig presses the first section of the steel casing 1.

[0035] S5, such as Figure 2 As shown, after the rotary drilling rig replaces the spiral drill bit 2, the spiral drill bit 2 is driven to rotate along the pile center axis of the reinforced concrete pipe pile 10 to press down and break the pile body 102, while discharging the slag soil.

[0036] S6, the rotary drilling rig is pressed into the second steel casing 1, and step S5 is repeated to complete the breaking and external discharge of the pile body 102 in the second steel casing 1. Similarly, the segmented breaking construction of the reinforced concrete pipe pile 10 is completed in sequence, and the remaining pile head including the pile shoe 103 at the bottom of the reinforced concrete pipe pile 10 is left unbroken.

[0037] S7, such as Figure 3 As shown, after the rotary drilling rig replaces the pick drill bit 3, the pick drill bit 3 is driven to rotate and move downward into the bottom of the last section of the steel casing 1 to clean the bottom and remove slag.

[0038] S8, such as Figure 4 As shown, a crawler crane is used to grab the remaining pile head at the bottom of the reinforced concrete pipe pile 10 through a stamping grab 4.

[0039] S9, such as Figure 5 As shown, the hole 202 is backfilled with backfill material 40 until it is level with the ground 201, and at the same time, each section of the steel casing 1 is pulled out in sequence from top to bottom.

[0040] In step S4 , the diameter of the steel casing 1 is Φ700-800 mm, and the gap between the inner hole of the steel casing 1 and the outer circle of the pulled out reinforced concrete pipe pile 10 is uniform, which is convenient for the spiral drill bit 2 to break the reinforced concrete pipe pile 10 .

[0041] like Figure 2As shown, in step S5, the bottom of the spiral drill bit 2 moved down to a position higher than the bottom of the steel casing 1, and the difference H1=50-100 cm between the two prevents the soil outside the steel casing 1 from collapsing. After the steel casing 1 is extended, it continues to rotate and press down to break the pile and remove the slag.

[0042] like Figure 3 As shown, in step S8, the height H2 of the remaining pile head is 100-250 cm.

[0043] like Figure 5 As shown, when the backfill material is backfilled into the hole 202 in step S9 and each section of the steel casing 1 is pulled out in sequence, the distance H3 between the top surface of the backfill material 40 and the bottom of the steel casing 1 still left underground is greater than 2m. This ensures that the soil outside the steel casing 1 is prevented from collapsing during the removal of the steel casing 1.

[0044] In step S9, the backfill material includes original soil mixed with lime, fluidized solidified soil excavated by the shield machine, C10-C15 low-grade concrete and M10-M15 low-grade mortar.

[0045] In addition to the above embodiments, the present invention may also have other implementation modes. All technical solutions formed by equivalent replacement and equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A construction method for removing reinforced concrete pipe piles in soft soil, characterized in that: The following steps are involved: S1. First, use the excavator bucket to remove the soil layer on the upper side of the cast-in-place reinforced concrete slab, then use the excavator to use a breaker hammer to break the cast-in-place reinforced concrete slab, and then use the excavator bucket to remove the reinforced concrete fragments until the cover plate on the top of each reinforced concrete pipe pile is completely exposed; S2. Use a total station or other measuring instruments to accurately collect the top elevation of the cover plate and the coordinates of the pile center; S3. Use an excavator to fill the backfill material into the excavated pit and level the site; S4, after the rotary drilling rig is in place, the drill frame is located directly above a reinforced concrete pipe pile in the construction area, the center position of the steel casing is determined according to the pile center coordinates of the reinforced concrete pipe pile measured in step S2, and the rotary drilling rig presses the first section of the steel casing; S5, after replacing the spiral drill bit of the rotary drilling rig, driving the spiral drill bit to rotate and press down along the pile center axis of the reinforced concrete pipe pile to break the pile body, and at the same time discharge the slag soil; S6, the rotary drilling rig is pressed into the second section of the steel casing, and step S5 is repeated to complete the breaking and external discharge of the pile body in the second section of the steel casing; and so on, the segmented breaking construction of the reinforced concrete pipe pile is completed in sequence, and the remaining pile head including the pile shoe at the bottom of the reinforced concrete pipe pile is not crushed; S7. After the pick drill bit is replaced in the rotary drilling rig, the pick drill bit is driven to rotate and move downward into the bottom of the last section of the steel casing to clean the bottom and remove the slag; S8. Use a crawler crane to grab the remaining pile head at the bottom of the reinforced concrete pipe pile through a punching grab bucket; S9. Use backfill material to backfill the hole until it is level with the ground. At the same time, pull out each section of the steel casing from top to bottom.

2. The construction method for removing reinforced concrete pipe piles in soft soil according to claim 1, characterized in that: In step S4, the diameter of the steel casing is Φ700-800 mm, and the gap between the inner hole of the steel casing and the outer circle of the pulled out reinforced concrete pipe pile is uniform.

3. The construction method for removing reinforced concrete pipe piles in soft soil according to claim 1, characterized in that: In step S5, the bottom of the drill bit after the spiral drill bit moves down to a position higher than the bottom of the steel casing, and the difference between the two is H1 = 50-100 cm.

4. The construction method for removing reinforced concrete pipe piles in soft soil strata according to claim 1, characterized in that: In step S8, the height of the remaining pile head is H=100-250 cm.

5. The construction method for removing reinforced concrete pipe piles in soft soil strata according to claim 1, characterized in that: In step S9, when the backfill material is used to fill the hole and when each section of the steel casing is pulled out in sequence, the distance H3 between the top surface of the backfill material and the bottom of the steel casing still remaining underground is greater than 2 m.

6. The construction method for removing reinforced concrete pipe piles in soft soil according to claim 1, characterized in that: In step S9, the backfill material includes original soil mixed with lime, fluidized solidified soil excavated by a shield machine, C10-C15 low-grade concrete and M10-M15 low-grade mortar.

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