A method for guiding hole construction of a lock catch steel pipe pile cofferdam

Abstract

The present application relates to a kind of lock catch steel pipe pile cofferdam hole leading construction method, first interval construction two pile holes, and setting wall steel casing is respectively arranged in two pile holes, then a pile hole is constructed with two pile holes occlusion between two interval pile holes;The above-mentioned construction process is circulated, while inserting and driving lock hole steel pipe pile in the pile hole that has been completed, until the insertion and driving of all steel pipe piles of lock catch steel pipe pile cofferdam are completed.Wall steel casing can support the effect to pile hole, effectively prevent the collapse of hole caused by insufficient compaction of backfill clay during hole leading, also can guide the excavation of occlusion pile hole, ensure the perpendicularity of pile hole.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology and relates to the construction of a cofferdam using interlocking steel pipe piles, specifically a method for constructing the pilot hole for a cofferdam using interlocking steel pipe piles. Background Technology

[0002] like Figure 1 As shown, interlocking steel pipe pile cofferdams are commonly used as temporary water-retaining structures in the construction of deep-water bridge piers, providing a dry environment for pier construction. An interlocking steel pipe pile cofferdam is a closed-loop structure composed of multiple steel pipe piles, each driven to a certain depth below the riverbed, with adjacent piles connected by interlocking links. During the construction of interlocking steel pipe pile cofferdams, in geological conditions such as clay layers, sand layers, and low-strength rock strata, the steel pipe piles are typically driven directly using a crawler crane and vibratory hammer. In geological conditions such as thick pebble layers and high-strength rock strata, the steel pipe piles often require pre-drilling. The construction method of the pre-drilling method is as follows:

[0003] like Figure 2 As shown, a large-diameter pilot-hole steel casing 2 is first vibrated at the designed driving position of the steel pipe pile. Drilling equipment such as rotary drilling rigs and impact drills are used to drill pile holes along the pilot-hole steel casing. After the pile hole is drilled to the driving depth of the steel pipe pile, clay 4 is backfilled into the pile hole. Then the steel casing 2 is pulled out, and the locking steel pipe pile 1 is driven into the pile hole. Then the clay inside the steel pipe pile is emptied, and concrete of a certain height is injected into the steel pipe pile to seal the bottom.

[0004] During the aforementioned pilot hole construction process, since the diameter of the drilled pile hole is larger than the diameter of the steel pipe pile, in order to ensure that adjacent steel pipe piles can be connected by interlocking, a portion of the adjacent pile holes must interlock with each other. However, under the conditions of gravel geological conditions, when drilling the next pile hole, if the clay backfill in the previous pile hole that it interlocks with is not compacted, it is easy to cause the previous pile hole to collapse, resulting in pilot hole failure. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a method for constructing pilot holes for cofferdams using interlocking steel pipe piles, thereby preventing hole collapse during the pilot hole construction process.

[0006] The technical solution of the present invention is as follows:

[0007] A method for constructing pilot holes for a cofferdam using interlocking steel pipe piles, characterized by the following steps:

[0008] (1) Layout three sequentially interlocking pile hole positions at the designed position on one side wall of the interlocking steel pipe pile cofferdam, namely hole position 1, hole position 2 and hole position 3.

[0009] (2) Insert pilot hole steel casings at hole positions 1 and 3 respectively, drill pile holes inside the two pilot hole steel casings to form pile hole 1 and pile hole 3; place a protective steel casing in pile hole 1 and pile hole 3 respectively.

[0010] The protective steel casing has an irregular shape, with the pipe walls on both opposite sides being concave arcs, and the arc diameter of the concave pipe wall is consistent with the outer diameter of the pilot hole steel casing. The pipe walls at both ends of the protective steel casing are convex arcs, and the arc diameter of the convex pipe wall is consistent with the inner diameter of the pilot hole steel casing.

[0011] The concave tube walls of the two protective steel casings are respectively set along the outline of the No. 2 hole position;

[0012] Clay was backfilled into pile holes No. 1 and No. 3, and then the steel casings of the two pilot holes were pulled out.

[0013] (3) Insert the pilot hole steel casing at the No. 2 hole position, drill the pile hole inside the pilot hole steel casing to form the No. 2 pile hole; backfill the No. 2 pile hole with clay, and pull out the pilot hole steel casing.

[0014] (4) Lay out the No. 4 hole position that engages with the No. 3 pile hole and the No. 5 hole position that engages with the No. 4 hole position in sequence; insert the pilot hole steel casing and drill a hole at the No. 5 hole position to form the No. 5 pile hole; pull out the protective steel casing in the No. 1 pile hole and insert it into the No. 5 pile hole; set one concave tube wall of the protective steel casing along the outline of the No. 4 hole position; backfill clay in the No. 5 pile hole and then pull out the pilot hole steel casing.

[0015] (5) Insert the pilot hole steel casing at hole position 4 to form pile hole 4; backfill clay into pile hole 4 and pull out the pilot hole steel casing.

[0016] (6) Repeat steps (4) and (5) to carry out subsequent pile hole construction. At the same time, insert locking steel pipe piles into the completed pile holes, hollow out the clay inside the steel pipe piles, and inject sealing concrete into the steel pipe piles to complete the construction of the locking steel pipe pile cofferdam.

[0017] This invention provides support for the pile hole by adding a protective steel casing inside the pile hole, effectively preventing the hole from collapsing due to insufficient compaction of the backfill clay during the drilling process. The protective steel casing also guides the interlocking steel casing with the already excavated pile hole and the pile hole excavation, ensuring the verticality of the pile hole. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the plan structure of a cofferdam with interlocking steel pipe piles;

[0019] Figure 2 This is a schematic diagram of a conventional pilot hole construction method;

[0020] Figure 3 This is a schematic diagram of the layout of three continuously interlocking pile holes;

[0021] Figure 4 This is a schematic diagram showing the status of two pile holes being constructed at intervals;

[0022] Figure 5 This is a schematic diagram showing the state of the pile holes where the two interlocking pile holes are engaged during construction.

[0023] Figure 6 This is a schematic diagram of the status of the intermittent pile holes during cyclic construction;

[0024] Figure 7 This is a schematic diagram showing the state of the interlocking pile holes during cyclic construction;

[0025] Figure 8 This is a schematic diagram of the cyclic construction method of the present invention. Detailed Implementation

[0026] The specific construction method of this invention is as follows:

[0027] (1) As Figure 3 As shown, three sequentially interlocking pile hole positions are laid out at the designed position on one side wall of the interlocking steel pipe pile cofferdam, namely hole position 101, hole position 2 102 and hole position 3 103.

[0028] (2) Figure 4 As shown, pilot steel casings 2 are inserted at hole positions 1 and 3 respectively. Piling holes are drilled inside the two pilot steel casings using drilling equipment such as rotary drilling rigs and impact drills to form pile hole 11 and pile hole 3. A protective steel casing 3 is placed in pile hole 1 and pile hole 3 respectively.

[0029] The protective steel casing 3 has an irregular structure, with the pipe walls on both opposite sides being concave arcs, and the arc diameter of the concave pipe wall is consistent with the outer diameter of the pilot hole steel casing. The pipe walls at both ends of the protective steel casing are convex arcs, and the arc diameter of the convex pipe wall is consistent with the inner diameter of the pilot hole steel casing.

[0030] The inner concave tube wall of the two protective steel casings 3 is respectively set along the outline of the second hole position 102;

[0031] Backfill clay into pile holes No. 1 and No. 3, and then pull out the steel casings 2 of the two pilot holes;

[0032] (3) Figure 5As shown, a pilot hole steel casing 2 is inserted at hole position 102, and a pile hole is drilled inside the pilot hole steel casing to form pile hole 12. When the pilot hole steel casing is inserted and the pile hole is excavated at hole position 2, the two protective steel casings 3 inside pile hole 11 and pile hole 3 can, on the one hand, support pile hole 1 and pile hole 2 to prevent pile hole 1 and pile hole 2 from collapsing, and on the other hand, guide the insertion of steel casing and the excavation of pile hole at hole position 2, which is conducive to maintaining the verticality of the steel casing insertion and pile hole drilling.

[0033] After drilling No. 2 pile hole 12 to the designed depth, clay was backfilled into No. 2 pile hole, and the pilot hole steel casing of No. 2 pile hole was pulled out.

[0034] (4) Figure 6 As shown, hole position 104, which engages with hole position 13 of pile 3, and hole position 105, which engages with hole position 105, are laid out in sequence; a pilot hole steel casing 2 is inserted and drilled at hole position 105 to form hole position 15 of pile 5; the protective steel casing 3 in hole position 11 of pile 1 is pulled out and inserted into hole position 15 of pile 5; one concave tube wall of the protective steel casing 3 is set along the outline of hole position 104 of pile 4; clay is backfilled in hole position 15 of pile 5; and then the pilot hole steel casing is pulled out.

[0035] (5) Figure 7 As shown, a pilot hole steel casing 2 is inserted at hole position 104 to form pile hole 14; clay is backfilled into pile hole 14, and then the pilot hole steel casing is pulled out.

[0036] (6) Figure 8 As shown, repeat steps (4) and (5), use the pre-hole steel casing 2 and the wall-protecting steel casing 3 to carry out subsequent pile hole construction, and at the same time, insert the locking steel pipe pile 1 into the completed pile hole, hollow out the clay inside the steel pipe pile, and inject sealing concrete into the steel pipe pile to complete the construction of the locking steel pipe pile cofferdam.

Claims

1. A method for constructing pilot holes for a cofferdam using interlocking steel pipe piles, characterized in that, Includes the following steps: (1) Layout three sequentially interlocking pile hole positions at the designed position on one side wall of the interlocking steel pipe pile cofferdam, namely hole position 1, hole position 2 and hole position 3. (2) Insert pilot hole steel casings at hole positions 1 and 3 respectively, drill pile holes inside the two pilot hole steel casings to form pile hole 1 and pile hole 3; place a protective steel casing in pile hole 1 and pile hole 3 respectively. The protective steel casing has an irregular shape, with the pipe walls on both opposite sides being concave arcs, and the arc diameter of the concave pipe wall is consistent with the outer diameter of the pilot hole steel casing. The pipe walls at both ends of the protective steel casing are convex arcs, and the arc diameter of the convex pipe wall is consistent with the inner diameter of the pilot hole steel casing. The concave tube walls of the two protective steel casings are respectively set along the outline of the No. 2 hole position; Clay was backfilled into pile holes No. 1 and No. 3, and then the steel casings of the two pilot holes were pulled out. (3) Insert the pilot hole steel casing at the No. 2 hole position, drill the pile hole inside the pilot hole steel casing to form the No. 2 pile hole; backfill the No. 2 pile hole with clay, and pull out the pilot hole steel casing. (4) Lay out the No. 4 hole position that engages with the No. 3 pile hole and the No. 5 hole position that engages with the No. 4 hole position in sequence; insert the pilot hole steel casing and drill a hole at the No. 5 hole position to form the No. 5 pile hole; pull out the protective steel casing in the No. 1 pile hole and insert it into the No. 5 pile hole; set one concave tube wall of the protective steel casing along the outline of the No. 4 hole position; backfill clay in the No. 5 pile hole and then pull out the pilot hole steel casing. (5) Insert the pilot hole steel casing at hole position 4 to form pile hole 4; backfill clay into pile hole 4 and pull out the pilot hole steel casing. (6) Repeat steps (4) and (5) to carry out subsequent pile hole construction. At the same time, insert locking steel pipe piles into the completed pile holes, hollow out the clay inside the steel pipe piles, and inject sealing concrete into the steel pipe piles to complete the construction of the locking steel pipe pile cofferdam.

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