Construction method for replacing old pile

Abstract

The invention provides a construction method for replacing an old pile, which comprises the following steps: excavating until the top of the old pile is exposed, excavating a plurality of resistance reducing holes for reducing pile pulling resistance in the circumferential direction of the old pile, installing a plurality of supporting devices to prevent the old pile from toppling over, and after the plurality of resistance reducing holes are excavated, pulling out the old pile by adopting a hoisting device to form an old pile hole. And the old pile hole and the multiple resistance reducing holes form a semi-excavation area so as to be continuously used for new pile construction. According to the construction method, the friction force between the old pile and the surrounding soil body can be reduced directly through drilling of an excavator in a construction site, the supporting device prevents the old pile from toppling over in the resistance reducing hole excavation process, the old pile is directly pulled out in a hoisting mode, the mechanical and labor cost during pile crushing and clearing is reduced, and a semi-excavation area formed through excavation in the period can be used for new pile construction again. The supporting device has the beneficial effects that the construction efficiency is high, the mechanical and labor cost in the construction process can be reduced, the construction method is simple, and the supporting device is low in manufacturing cost, detachable, reusable and convenient to popularize.

Description

Technical Field

[0001] The invention belongs to the technical field of construction engineering, and in particular relates to a construction method for replacing old piles. Background Art

[0002] In the existing technology, when old buildings are demolished and new buildings are constructed, pile foundation construction may encounter the situation where old piles affect the construction of new piles. When replacing old and new piles, crushing cones are generally used to hammer and crush the old piles, and then remove them for new pile construction. The construction cycle of crushing and removing old piles is long, the labor cost is high, and the construction process requires the use of multiple machines such as crushing hammers, which have high machine costs and site environment requirements. There are technical problems such as low construction efficiency and high construction costs of machines and labor. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a construction method for replacing old piles, which is particularly suitable for replacing old piles efficiently and at low cost by using an existing excavator at a construction site to replace a crushing cone.

[0004] The technical solution adopted by the present invention is: a construction method for replacing old piles, comprising the following steps: determining the pile position and excavating until the top of the old pile is exposed, detecting the pile diameter and pile depth of the old pile; excavating a plurality of resistance reduction holes for reducing the resistance of pile extraction along the circumference of the old pile and installing a plurality of supporting devices to prevent the old pile from tipping over; using a lifting device to remove the old pile to form an old pile hole, and the old pile hole and the plurality of resistance reduction holes form a semi-excavated area; backfilling / excavating the semi-excavated area according to the size of the new pile to form a new pile hole, and installing the new pile in the new pile hole.

[0005] Furthermore, excavating a plurality of resistance reduction holes for reducing the resistance to pile extraction along the circumference of the old pile and installing a plurality of supporting devices to prevent the old pile from toppling over comprises: the plurality of resistance reduction holes are formed by a symmetrical excavation method and the center point surrounded by the plurality of resistance reduction holes coincides with the axis of the old pile.

[0006] Furthermore, a plurality of resistance reduction holes for reducing the resistance to pile extraction are excavated along the circumference of the old pile and a plurality of supporting devices are installed to prevent the old pile from toppling over, including: when the preset aperture of the new pile hole is larger than the aperture of the old pile hole, the aperture of each resistance reduction hole is not larger than half of the aperture difference between the new pile hole and the old pile hole.

[0007] Furthermore, excavating a plurality of resistance reduction holes for reducing pile pulling resistance along the circumference of the old pile and installing a plurality of support devices to prevent the old pile from toppling over comprises: the plurality of support devices are symmetrically arranged with the pile axis of the old pile as the center.

[0008] Furthermore, the supporting device includes a supporting member and a fixing member, the fixing member can be inserted into the soil around the old pile for fixing, the supporting member is connected to the fixing member and the supporting member can support the old pile.

[0009] Furthermore, the supporting device also includes a butt plate that can fit with the old pile, the butt plate is connected to the end of the supporting member away from the fixing member, and the butt plate and the fixing member are respectively vertically connected to the supporting member.

[0010] Furthermore, the supporting device also includes bolts, and the abutment plate is connected to the old pile by bolts to be stable.

[0011] The advantages and positive effects of the present invention are as follows: due to the adoption of the above-mentioned technical scheme, the friction between the old piles and the surrounding soil can be reduced by drilling holes directly through the excavator at the construction site, the supporting device can prevent the old piles from tipping over during the excavation of the resistance reduction holes, the old piles can be directly pulled out by hoisting, and the mechanical and labor costs for pile crushing and removal can be reduced. The semi-excavated areas formed during the excavation can be reused for the construction of new piles; it has the advantages of high construction efficiency, low construction machinery and labor costs, simple construction method, low manufacturing cost of the supporting device, detachable and reusable, and easy promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a plan view of a construction scene of the present invention.

[0013] Figure 2 This is a schematic elevation diagram of a construction scene of the present invention.

[0014] In the figure:

[0015] 1. Old pile 2. Resistance reduction hole 3. New pile hole

[0016] 4. Fixing parts 5. Support parts 6. Abutment plate

[0017] 7. Bolts DETAILED DESCRIPTION

[0018] The embodiments of the present invention are described below in conjunction with the drawings. The described embodiments are only a part of the embodiments of the invention, rather than all the embodiments.

[0019] 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.

[0020] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, and may refer to direct connection, installation or fixation, or indirect connection, installation or fixation, and the present invention does not limit this.

[0021] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] like Figure 1 to Figure 2 As shown, a construction schematic diagram of an embodiment of a construction method for replacing old piles of the present invention is shown.

[0023] A construction method for replacing old piles comprises the following steps:

[0024] When the new pile is constructed and the old pile 1 is blocked and needs to be replaced, the pile position is first determined and excavated until the top of the old pile 1 is exposed. The pile diameter and pile depth of the old pile 1 can be detected first, and ultrasonic detection can be used to detect whether the old pile 1 is broken, so as to ensure that when the old pile 1 is replaced by this method, the old pile 1 will not be broken during the extraction process.

[0025] According to the detection results of the old pile 1 and the preset construction parameters of the new pile, a suitable rotary drilling bit is selected, and multiple resistance reduction holes 2 that can be used to reduce the resistance of pile extraction are excavated along the circumference of the old pile 1, and multiple supporting devices are installed to support the old pile 1 and prevent the old pile 1 from falling. During excavation, the rotary drilling machine already available at the construction site can be used. The aperture of each resistance reduction hole 2 and the drill bit of the rotary drilling machine can be set according to the difference in pile diameter between the old pile 1 and the new pile. When the preset aperture of the new pile hole 3 is larger than the aperture of the old pile hole, the aperture of each resistance reduction hole 2 is not larger than half of the difference between the aperture of the new pile hole 3 and the old pile hole, and the preset pile axis of the new pile can coincide with the pile axis of the old pile 1. According to this construction method, after the old pile 1 is pulled out, the pile hole of the old pile 1 and the multiple resistance reduction holes 2 left behind can continue to be used for the installation and construction of the new pile. Effective excavation can improve construction efficiency and avoid waste of construction costs.

[0026] In this embodiment, the number of the resistance reduction holes 2 and the supporting devices is not less than four. In other embodiments, the number of the resistance reduction holes 2 and the supporting devices can be adaptively adjusted according to construction requirements.

[0027] In this embodiment, multiple resistance reduction holes 2 can be formed by symmetrical excavation. First, a resistance reduction hole 2 is excavated, and a support device is installed at the excavated resistance reduction hole 2. Bolts 7 can be used to fix the support member 5 to the old pile 1, and the fixing member 4 is inserted into the surrounding soil and squeezed by the surrounding soil to stabilize the support device, thereby supporting and fixing the old pile 1. The length of the support member 5 is greater than the aperture of the resistance reduction hole 2 to meet the requirement that the fixing member 4 can be inserted outside the resistance reduction hole 2 and away from the soil position of the old pile 1; with the pile axis of the old pile 1 as the center, another resistance reduction hole 2 is symmetrically excavated and the support device is installed synchronously. The two sets of support devices A support is formed for the old pile 1 in the front-to-back direction; two resistance reduction holes 2 can be further excavated on the left and right sides of the old pile 1 and the supporting device can be used to support the old pile 1 in the left and right direction. By symmetrical excavation and installation of four sets of supporting devices during the excavation, support is formed for the old pile 1 in all directions, which can ensure that the old pile 1 is stable and safe when the subsequent resistance reduction holes 2 are continued to be excavated, and prevent the old pile 1 from tipping over; the remaining resistance reduction holes 2 are excavated in other areas around the old pile 1 and outside the installed supporting devices, and the supporting devices are not installed or an increased number of supporting devices are installed according to construction requirements.

[0028] During the construction process, the elevation of each resistance reduction hole 2 is lower than the bottom elevation of the old pile 1. Multiple resistance reduction holes 2 are connected and connected to ensure that the old pile 1 is completely exposed, minimizing the resistance to pile extraction. The center point surrounded by the multiple resistance reduction holes 2 coincides with the axis of the old pile 1. Multiple support devices are symmetrically arranged with the axis of the old pile 1 as the center.

[0029] In the specific construction process, the installation position of the support device should not affect the excavation construction of multiple resistance reduction holes 2; when drilling, mud wall protection can be used to avoid hole collapse during drilling. When there is a lot of groundwater or gravel formation, mud circulation wall protection is used to assist drilling, which can play a dual role of carrying slag and protecting the wall. After all resistance reduction holes 2 are excavated and each support device is installed, the old pile 1 is pulled out to form an old pile hole through a lifting device, such as a crane already available at the construction site. The old pile hole and multiple resistance reduction holes 2 form a semi-excavation area. The lifting device can select an appropriate machine according to the machine model at the construction site and the weight of the pile body of the old pile 1. Different lifting ears are used according to the pile type. For example, if it is a reinforced concrete pile, the pile head can be broken and the lifting ear can be made using the steel bars of the old pile 1 itself; if it is a plain concrete pile, a clamp that matches the pile head of the old pile 1 can be made, and a lifting ear is set on the clamp, and the old pile 1 is pulled out using the lifting device. After the old pile 1 is connected to a lifting device, such as a crane, through the lifting lugs and before the old pile 1 is removed, the installed multiple supporting devices can be removed first, and then the old pile 1 can be lifted out, and then the semi-excavated area can be backfilled / excavated according to the size of the new pile to form a new pile hole 3, and the new pile can be installed in the new pile hole 3. The hole mouth can be buried by a steel sleeve, and if the preset depth of the new pile hole 3 is greater than the depth of the semi-excavated area, the hole can be further excavated in the semi-excavated area until the preset depth is reached; if the preset depth of the new pile hole 3 is less than the depth of the semi-excavated area, it can also be selected to directly pour concrete to form a new pile according to construction requirements, reducing the backfilling process and improving construction efficiency.

[0030] The present invention can utilize the existing excavator drilling holes on the construction site to reduce the friction between the old pile 1 and the surrounding soil, use a support device to fix the old pile 1, prevent the old pile 1 from falling over to improve the safety and stability of the construction, and directly remove the old pile 1 by a hoisting method such as a crane, without the need to introduce additional construction equipment such as a crushing cone. Compared with the construction of the old pile 1 using a damaged and then removed method, the mechanical and labor costs of pile crushing and removal can be reduced, the construction period can be reduced, and the machine and labor costs can be reduced. The construction method has a low cost, and the unforeseen risks of underground projects are small. The semi-excavated area caused by the excavation during the construction process can continue to be used for the construction of new piles, while ensuring the quality of the new pile construction. The support device can be reused, saving construction costs. This method can not only be used for the construction of new piles to replace old piles 1, but can also be promoted and applied to the construction of old piles that need to be removed.

[0031] In this embodiment, the support device includes a support member 5 and a fixing member 4. The fixing member 4 can be inserted into the soil around the old pile 1 to fix it. The support member 5 is connected to the fixing member 4 and the support member 5 can support the old pile 1. In this embodiment, the support member 5 and the fixing member 4 are vertically connected in an L shape. The vertical setting facilitates the fixing member 4 to be inserted vertically into the soil more smoothly, and the support member 5 can fit with the soil surface to be stable.

[0032] In this embodiment, the support device further includes a butt plate 6 that can fit with the old pile 1, the butt plate 6 is connected to the end of the support member 5 away from the fixing member 4, and the butt plate 6 and the fixing member 4 are respectively vertically connected to the support member 5. The butt plate 6 can increase the contact area between the support member 5 and the old pile 1, improve the fixing effect during support, make the old pile 1 more stable, prevent the old pile 1 from falling during the excavation of the resistance reduction hole 2, improve the safety of the construction process, and ensure construction safety.

[0033] In this embodiment, the support device also includes bolts 7, and the abutment plate 6 is connected to the old pile 1 through the bolts 7 to be stable. Usually, expansion screws can be selected as bolts 7 during construction, the support member 5 is made of steel, and the fixing member 4 is also made of metal materials such as steel. The support device can be prefabricated in advance, or the remaining materials on the construction site can be selected, and the fixing member 4 and the support member 5 are fixedly connected by welding. The materials are easy to obtain, the production cost is low, and the pile can be disassembled and reused. The device is simple and can ensure that the old pile 1 is stable before being removed, thereby improving construction safety.

[0034] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A construction method for replacing old piles, characterized in that: The steps include: Determine the pile position and excavate until the top of the old pile is exposed, and detect the pile diameter and pile depth of the old pile; Digging a plurality of resistance-reducing holes along the circumference of the old pile to reduce the resistance to pile pulling and installing a plurality of supporting devices to prevent the old pile from falling over; The old pile is pulled out by a lifting device to form an old pile hole, wherein the old pile hole and the plurality of resistance reduction holes form a semi-excavation area; The semi-excavated area is backfilled / excavated to form a new pile hole according to the size of the new pile, and the new pile is installed in the new pile hole.

2. The construction method for replacing old piles according to claim 1, characterized in that: Excavating a plurality of resistance-reducing holes for reducing the resistance to pile pulling along the circumference of the old pile and installing a plurality of supporting devices to prevent the old pile from falling down comprises: The plurality of resistance reduction holes are formed by symmetrical excavation, and the center point surrounded by the plurality of resistance reduction holes coincides with the axis of the old pile.

3. The construction method for replacing old piles according to claim 1, characterized in that: Excavating a plurality of resistance-reducing holes for reducing the resistance to pile pulling along the circumference of the old pile and installing a plurality of supporting devices to prevent the old pile from falling down comprises: When the preset hole diameter of the new pile hole is larger than the hole diameter of the old pile hole, the hole diameter of each of the resistance reduction holes is not larger than half of the difference between the hole diameters of the new pile hole and the old pile hole.

4. The construction method for replacing old piles according to claim 1 is characterized in that: Excavating a plurality of resistance-reducing holes for reducing the resistance to pile pulling along the circumference of the old pile and installing a plurality of supporting devices to prevent the old pile from falling down comprises: The plurality of support devices are symmetrically arranged with the pile axis of the old pile as the center.

5. The construction method for replacing old piles according to any one of claims 1 to 4, characterized in that: The supporting device comprises a supporting member and a fixing member, wherein the fixing member can be inserted into the soil around the old pile for fixing, and the supporting member is connected to the fixing member and can support the old pile.

6. The construction method for replacing old piles according to claim 5, characterized in that: The supporting device also includes a butt plate that can fit with the old pile, the butt plate is connected to the end of the supporting member away from the fixing member, and the butt plate and the fixing member are respectively vertically connected to the supporting member.

7. The construction method for replacing old piles according to claim 6, characterized in that: The supporting device also includes bolts, and the abutment plate is connected to the old pile by the bolts to be stabilized.

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