CN113107019A - Pre-buried anchor rod connecting structure passing through pre-built building and construction method thereof - Google Patents

Pre-buried anchor rod connecting structure passing through pre-built building and construction method thereof Download PDF

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Publication number
CN113107019A
CN113107019A CN202110343927.5A CN202110343927A CN113107019A CN 113107019 A CN113107019 A CN 113107019A CN 202110343927 A CN202110343927 A CN 202110343927A CN 113107019 A CN113107019 A CN 113107019A
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China
Prior art keywords
anchor rod
section
built
pile
free section
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李钦锐
李湛
段启伟
唐君
闫双跃
江宁
李鹏
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Cabr Foundation Engineering Co ltd
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Cabr Foundation Engineering Co ltd
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Priority to CN202110343927.5A priority Critical patent/CN113107019A/en
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    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D31/00Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/02Foundation pits
    • E02D17/04Bordering surfacing or stiffening the sides of foundation pits
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D33/00Testing foundations or foundation structures
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D37/00Repair of damaged foundations or foundation structures
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/74Means for anchoring structural elements or bulkheads
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2600/00Miscellaneous
    • E02D2600/20Miscellaneous comprising details of connection between elements
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2600/00Miscellaneous
    • E02D2600/30Miscellaneous comprising anchoring details

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  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Foundations (AREA)

Abstract

The invention discloses a pre-buried anchor rod connecting structure passing through a pre-built building and a construction method thereof. The cement grout body is arranged, so that a foundation is provided for anchoring; the anchor rod extends obliquely downwards, so that the anchoring force can be provided in the largest range; the anchor rod free section is arranged, so that the early-stage anchoring effect can be ensured; through the arrangement of the anchoring conversion piece and the elastic pipe, the stress transmission, transition and protection of anchoring of the anchor rod are facilitated. The method does not influence the construction of the first-built building and does not cause excessive construction period and cost influence on the next foundation pit excavation project in the later period.

Description

Pre-buried anchor rod connecting structure passing through pre-built building and construction method thereof
Technical Field
The invention belongs to the technical field of anchor rod construction, and particularly relates to a pre-buried anchor rod connecting structure passing through a pre-built building and a construction method thereof.
Background
At present, with the rapid development of urban construction, urban land is more and more tense, and in order to fully improve the utilization rate of underground space, the underground part of a high-rise building is also increased continuously, and a foundation pit is larger and deeper. The anchor rod technology is an efficient and economic rock and soil mass reinforcement technology and is widely applied to deep foundation pit engineering of buildings. However, during actual building construction, when a foundation pit is excavated after a building is built, if the foundation pit adopts technologies such as support piles and geographical processing, anchor rods are not favorably arranged; the adoption of other cantilever piles, double-row piles or the adoption of schemes of support piles, island excavation and later-stage support increase can cause a large amount of cost and time expenditure. In addition, the requirements of meeting the safety of the structure of the basement, ensuring the safe and smooth construction of the basement and ensuring the safety of the surrounding environment, buildings and road pipelines are also met, and meanwhile, the aims of minimizing the influence of the construction on the surrounding environment, reducing underground pollution and reducing the manufacturing cost are also achieved.
Disclosure of Invention
The invention provides a pre-buried anchor rod connecting structure passing through a pre-built building and a construction method thereof, which are used for solving the technical problems of pre-burying of an anchor rod required by reinforcing a foundation pit on one side in a pre-built building project, convenience in installation, cost and time saving and the like.
In order to achieve the purpose, the invention adopts the following technical scheme:
a pre-buried anchor rod connecting structure passing through a pre-built building comprises the existing ground where one side of the pre-built building is located, a foundation pit arranged on the other side of the pre-built building, a pre-built foundation connected to the soil body under the pre-built building, a pre-built mattress layer connected to the lower portion of the pre-built foundation, a foundation reinforcing pile connected to the inner portion of the soil body under the pre-built mattress layer, a supporting pile connected to one side, close to the foundation pit and the pre-built building, a crown beam connected to the top of the supporting pile, an anchor rod free section pre-penetrated into the crown beam and the pre-built mattress layer, an anchor rod fixing section connected to the tail end of the anchor rod free section and connected to the lower portion of the existing ground, an anchor conversion piece connected to the joint of the anchor rod free section and;
and a protective pipe penetrates through the free section of the anchor rod, and is embedded in the mattress layer and/or the crown beam built in advance.
Furthermore, the anchoring conversion piece comprises an anchoring beam, a supporting column connected to the lower part of the anchoring beam and a conversion pore channel arranged in the anchoring beam;
the conversion pore passage is an arc pore passage, the upper end of the arc pore passage corresponds to the free section of the anchor rod, the lower end of the arc pore passage corresponds to the fixed section of the anchor rod, and the inside of the arc pore passage is a straight-in section of the free section of the anchor rod and the fixed section of the anchor rod; or two conversion pore channels are provided, and one conversion pore channel is a linear pore channel and is connected and fixed corresponding to the free section of the anchor rod in a penetrating way; the other conversion pore passage is a diagonal pore passage which is arranged corresponding to the anchor rod fixing section, and the straight line pore passage and the diagonal pore passage are not communicated.
Furthermore, the foundation reinforcing piles are arranged in a quincunx shape or a local quincunx shape, and the height of the bottom of each foundation reinforcing pile is lower than that of each support pile; the foundation reinforcing pile comprises a CFG pile, a cast-in-situ bored pile or a precast tubular pile.
Furthermore, the crown beam is arranged on the top of the support pile in a through length mode, the thickness of the crown beam is larger than that of the first-built mattress layer and is not smaller than 500mm, and the middle point of the crown beam and the middle point of the first-built mattress layer are at the same horizontal height.
Further, the free sections of the anchor rods are arranged at intervals in the mattress of the prior building, and the length of the free sections of the anchor rods is larger than the horizontal distance between the crown beams and the outer edge of the prior building; the outer end of the free section of the anchor rod penetrates through the crown beam and is connected through a fastener, and the fastener comprises a tensioning plate and a fastening nut.
Furthermore, the anchor rod fixing section is obliquely arranged under the existing ground, and the high end of the anchor rod fixing section is connected with the anchor rod free section; the connecting part of the anchor rod fixing section and the anchor rod free section is in an arc shape or staggered arrangement, and the connecting part is sleeved through an elastic pipe and has the length not less than 20 cm; the included angle between the anchor rod fixing section and the ground where the mattress layer is built in advance is not less than 15 degrees.
Further, the construction method for penetrating through the pre-buried anchor rod connecting structure under the pre-built building comprises the following specific steps:
step one, constructing foundation reinforcing piles according to the design requirements of a building constructed in advance, and then embedding protective pipes at equal intervals while constructing a mattress layer, so that the construction of an upper structure is continued after the mattress layer is constructed;
secondly, designing a construction drawing of foundation pit support according to the depth of the foundation pit on one side of the first-built building and the load condition of the first-built building, and constructing a support pile according to the drawing; meanwhile or in the separation time, constructing an anchor rod fixing section and a cement grouting body on the other side of the building in advance according to the design angle, and burying the anchor rod fixing section and the cement grouting body in the soil body at the lower part of the existing ground;
constructing a crown beam and an anchoring conversion part, embedding a protective pipe in the crown beam, and presetting a conversion pore channel in the anchoring conversion part; one end of the anchor rod fixing section is connected with the anchor rod free section, and the connection part is connected through the anchoring conversion part; the steel strand is connected with the free section of the anchor rod in the protective pipe in a penetrating way, and the butt joint of the fixed section of the anchor rod and the free section of the anchor rod can adopt a joint connector and ensure the arrangement of the joint connector along the length direction; the other end of the free section of the anchor rod penetrates through the protective pipe and is anchored on the crown beam;
when the anchoring conversion piece is internally provided with an arc-shaped pore channel, the free section of the anchor rod is connected with the fixed section of the anchor rod in advance and is temporarily fixed on the crown beam, and then the free section of the anchor rod is fastened according to the anchoring requirement; when two conversion pore channels are arranged in the anchoring conversion piece, one conversion pore channel is a linear pore channel and is pre-connected with the free section of the anchor rod in a penetrating way and then fixed according to requirements; the other conversion pore passage is a diagonal pore passage, the diagonal pore passage is fixedly arranged corresponding to the anchor rod fixing section, and the straight line pore passage and the diagonal pore passage are not communicated;
step four, the connecting part of the anchor rod fixing section and the anchor rod free section is a conversion section, the anchor rod free section is horizontal at the ground where the pre-built building is located, and the anchor rod fixing section is obliquely arranged; the conversion section is connected in a penetrating way through the anchoring conversion piece; the length of the cross-under is not less than 20 cm;
and fifthly, detecting that the tensioning acting force of the free section of the anchor rod meets the design requirement, then monitoring the stress and deformation of the excavated foundation pit, the free section of the anchor rod and each pile body in real time, and timely early warning and controlling through the monitoring result.
Furthermore, for the fourth step, the horizontal anchoring length of the end part of the anchor rod fixing section in the existing ground is not less than the horizontal width of the building firstly, the included angle between the anchor rod fixing section and the ground where the mattress layer is built firstly is 15-25 degrees, and the locking value of the anchor rod fixing section during tensioning is improved according to the design requirement.
Further, the detection number of the anchor rod fixing sections in the step five is not less than 5% of the total number of the anchor rod fixing sections, and the detection number of the anchor rod fixing sections in the same soil layer is not less than 3; the monitoring and early warning indexes of the anchor rod fixing section at least comprise axial force and horizontal displacement of the anchor rod fixing section.
Further, in the fifth step, the support piles are detected by a low-strain detection method, the detection number of the low-strain method is 20% of the total construction pile number, and the integrity of the pile body is detected by not less than 5 single projects in a low-strain dynamic mode; in addition, for the monitoring and early warning indexes of the pile body, at least the horizontal movement monitoring of the pile top, the settlement of the pile top and the horizontal displacement of the deep layer of the pile body are carried out.
The invention has the beneficial effects that:
1) the arrangement of the anchor rods and the cement grout body embedded under the prior building is favorable for providing a foundation for the integral anchoring of the connecting structure; the anchor rod extends obliquely downwards, so that the anchoring force can be provided in the largest range; in addition, the cement grout body is embedded in advance, so that the anchor rod is convenient to install and construct;
2) according to the invention, the anchor rod free section is arranged in the mattress layer built in advance, so that the early anchoring effect can be ensured, and the installation and construction can be carried out under the condition of not changing the supporting pile and foundation treatment scheme; therefore, the construction cost and the construction time can be greatly saved under the condition of ensuring the design and construction requirements;
3) according to the invention, through the design of the anchor conversion piece of the anchor rod free section and the anchor rod at the connecting end and the arrangement of the elastic pipe, the force transmission of anchor rod anchoring is facilitated, and the effective transition and protection at the turning part are realized;
4) by the method, after the protective pipe is pre-embedded in the mattress layer, the construction of the first-built building can not be influenced, and the influence on too much construction period and cost of the next foundation pit excavation project in the later period can not be caused.
In addition, the free section of the anchor rod is fastened on the crown beam, so that convenient construction is facilitated, and support, foundation treatment and anchoring are further connected integrally; the invention can carry out adaptability adjustment according to the construction and the working surface of subsequent foundation pit excavation, and can be greatly suitable for site construction; additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention; the primary objects and other advantages of the invention may be realized and attained by the instrumentalities particularly pointed out in the specification.
Drawings
FIG. 1 is a schematic construction view of a pre-buried anchor rod connecting structure passing through a pre-built building;
FIG. 2 is a schematic view of the connection and fixation of the anchor free section at the crown beam;
FIG. 3 is a schematic view of the anchor fixing and anchoring transition piece connection;
FIG. 4 is a first schematic view of the anchoring converter;
FIG. 5 is a structural view of the anchoring converter II;
fig. 6 is a schematic view of the connection of the anchoring beam and the supporting column.
Reference numerals: 1-existing ground, 2-foundation construction, 3-mattress construction, 4-foundation pit bottom foundation, 5-foundation pit cushion, 6-foundation pit bottom, 7-drainage ditch, 8-support pile, 9-foundation reinforcement pile, 10-crown beam, 11-anchor rod free section, 12-anchor rod fixed section, 13-cement grout, 14-anchor conversion piece, 141-anchor beam, 142-support column, 143-conversion pore channel, 15-protective pipe and 16-fastening piece.
Detailed Description
Taking a certain proposed project as an example, the proposed project comprises 1# commercial buildings, 2# commercial buildings, 3# to 6# residential buildings and underground garages.
When the foundation pit supporting construction is carried out on the 3# to 6# residential buildings and the underground garages, the 1# and 2# commercial buildings are already capped; the main structure of the commercial building is 5 floors above the ground, no basement or strip foundation is provided, the absolute elevation of the foundation bottom is 34.600, and CFG pile composite foundation and quincunx pile arrangement are adopted. 3# 6# residential building, 6 ~ 8 layers on the ground, 2 layers underground, raft foundation adopts CFG stake composite foundation to handle, and mattress layer bottom is-8.750, and absolute elevation is 29.050. Underground 2 layers of the underground garage, raft foundations and a bedding bottom elevation of-8.550, wherein the absolute elevation is 29.250. The southeast and northwest corners are locally deeper.
According to the geotechnical engineering investigation report, the upper part of the 35m depth range of the investigation is filled with soil, the lower part of the investigation is a newly deposited layer and a general fourth series flood flushing layer, and the total number of the layers is 9. According to the geotechnical engineering investigation report, affected by the drilling process, three layers of underground water are exposed in the investigation period: the type of the first layer of underground water is upper layer stagnant water, the stable water level burial depth is 4.05-8.90 m, and the elevation is 28.42-33.79 m. The type of the second layer of underground water is diving, the stable water level burial depth is 7.50-14.25 m, and the elevation is 23.54-27.96 m. The type of the third layer of underground water is micro pressure-bearing water, the burial depth of the stable water level is 28.90m, and the elevation is 9.06 m.
According to engineering geology and hydrogeology conditions, and from the comprehensive consideration of economy and technology, the supporting scheme adopts a pile-anchor supporting scheme. The construction of the east-side embedded protective pipe and the anchor rod in the area is the key and difficult point of the foundation pit supporting design. The foundation of the 1# and 2# buildings is taken as a first-built foundation 2, the mattress layer below the first-built foundation 2 is taken as a first-built mattress layer 3, and the foundation is treated into a CFG pile composite foundation. When the design work of foundation pit supporting on one side of the 1# and 2# buildings is carried out, the CFG piles of the 1# and 2# buildings are constructed, the mattress layer is laid, and a concrete mattress layer is arranged according to the working procedures and urgent needs. 1# and 2# floor CFG pile composite foundation, quincunx cloth pile, stock can't pass through the CFG stake, can't be under construction. According to the unified construction arrangement of project department, when the deep foundation pit of later stage was excavated, according to 1#, 2# building structure needs to consider according to having sealed the top, 5 layers on the ground, the foundation pit is closely excavated near 1#, 2# building, needs dig 5.35~6.95m deeply again. Through calculation and analysis, the horizontal displacement of the pile top of the cantilever pile is more than 329mm, and the cantilever pile and the double-row pile can not meet the requirements of design and field construction. For the anchor rod can not be constructed, under the condition that the cantilever pile is not feasible, if the scheme of supporting the pile 8+ the inner support is adopted, the south and the north of the foundation pit are about 175m, the east and the west are about 60m, and the cost of foundation pit support, the measure cost of main body construction and the construction period can be greatly increased no matter which supporting mode is adopted.
As shown in fig. 1 and 2, a pre-buried anchor rod connecting structure passing through a pre-built building, the foundation pile comprises an existing ground 1 on one side of a building, a foundation pit arranged on the other side of the building, a foundation 2 connected to a soil body below the building, a mattress layer 3 connected to the foundation 3, a foundation reinforcing pile 9 connected to the inside of the soil body below the mattress layer 3, a supporting pile 8 connected to one side of the foundation pit adjacent to the building, a foundation pit bottom foundation 4 connected to a foundation pit bottom 6 at the bottom of the supporting pile 8, a foundation pit cushion layer 5, a crown beam 10 connected to the top of the supporting pile 8, an anchor rod free section 11 pre-penetrated into the crown beam 10 and the mattress layer 3, an anchor conversion part 14 connected to the joint of the anchor rod free section 11 and the anchor rod fixed section 12, an anchor rod fixed section 12 connected to the tail end of the anchor rod free section 11 and connected to the lower side of the existing ground 1, and a cement grout body 13 sleeved on the periphery of the anchor rod fixed section 12; the cement grout body 13 is pre-embedded in the soil body of the pre-built building; the anchor rod free section 11 is externally connected with a protective pipe 15 in a penetrating mode, and the protective pipe 15 is embedded in the mattress layer 3 and the crown beam 10 which are built in advance.
In this embodiment, the pre-embedded protection pipe 15 is a steel protection pipe, has an elevation of 34.350m, and is pre-embedded in a constructed CFG pile mattress layer of a # 1 commercial building or a #2 commercial building. The protective pipe 15 adopts a phi 48, the wall thickness is 3.25mm, and the butt joint adopts a welding mode; the free section 11 of the anchor rod is adopted as 3 bundles of the free section 11 with the diameter of 7 phi 5 phi s 15.2. The anchoring section outside the protective pipe 15 needs to be constructed on two layers of external outriggers, such as the east side of a No. 1 building and a No. 2 building, the earth in the region is excavated to the bottom elevation of the cushion layer for construction, and the working surface needs to be determined on site.
In the embodiment, the support piles 8 are formed by adopting a long spiral hole-forming concrete post-dowel steel pile forming process, the support piles 8 are arranged in rows at the side edge of the foundation pit, and the distance between the support piles 8 and the side edge of the foundation pit bottom foundation 4 is at least 800 mm; still be provided with escape canal 7 between fender pile 8 and foundation ditch bottom basis 4, 7 top height in escape canal are not higher than 5 bottom surface height of foundation ditch bed course. The foundation reinforcing piles 9 are CFG piles which are arranged in a quincunx shape or are arranged in a partial quincunx shape, and the height of the bottom of each foundation reinforcing pile 9 is lower than that of each support pile 8; the foundation stabilization pile 9 further includes a cast-in-situ bored pile or a precast tubular pile.
In this embodiment, the cross section of the crown beam 10 is square, the crown beam is arranged at the top of the support pile 8 in a through length manner, the thickness of the crown beam 10 is larger than that of the first-built mattress layer 3, and the middle point of the crown beam 10 and the middle point of the first-built mattress layer 3 are at the same horizontal height.
In the embodiment, the anchor rod free section 11 is arranged in the mattress layer 3 built in advance at intervals, and the length of the anchor rod free section 11 is larger than the horizontal distance between the crown beam 10 and the outer edge of the building built in advance. The outer end of the anchor rod free section 11 passes through the crown beam 10 and is connected by a fastener 16. The fastener 16 comprises a tensioning plate and a fastening nut.
In this embodiment, the anchor rod fixing section 12 is arranged obliquely under the existing ground 1, and the high end of the anchor rod fixing section 12 is connected with the anchor rod free section 11. The connecting part of the anchor rod fixing section 12 and the anchor rod free section 11 is in an arc shape or staggered arrangement, and the connecting part is sleeved through an elastic pipe and has the length not less than 20 cm; the included angle between the anchor rod fixing section 12 and the ground where the mattress layer 3 is built in advance is 15-20 degrees.
In this embodiment, stock free section 11 is pre-buried, the anchor section is by mechanical construction, should notice two problems in the construction: firstly, the construction positioning and the angle are accurate as much as possible, and the free section 11 of the anchor rod is prevented from being bent on the plane; secondly, the free section is longer and there is 20 degrees angles at the anchor section, and the locking value needs to be improved properly when the anchor rod is stretched. When temporary drainage is required, a temporary sewage pipe 14 is arranged above the anchor rod.
As shown in fig. 3 to 6, the anchor free section 11 and the anchor fixed section 12 are adjoined at the anchor transition piece 14. The anchoring conversion part 14 includes an anchoring beam 141, supporting columns 142 connected to the lower portion of the anchoring beam 141 at intervals, and a conversion hole 143 disposed inside the anchoring beam 141; the anchoring beam 141 and the supporting column 142 are made of concrete, wherein the cross section of the anchoring beam 141 is a trapezoidal section. The conversion hole channels 143 are arranged one by one corresponding to the connection of the anchor rod free section 11 and the anchor rod fixed section 12, and the anchor beam 141 can be arranged in a segmented or full-length mode within the connection range of the anchor rod free section 11 and the anchor rod fixed section 12.
As shown in fig. 5, the conversion hole 143 is an arc hole, the upper end of the arc hole corresponds to the free section of the anchor rod, the lower end of the arc hole corresponds to the fixed section of the anchor rod, and the inside of the arc hole is the direct-connection section of the free section of the anchor rod and the fixed section of the anchor rod. As shown in fig. 6, there are two conversion hole channels 143, and one conversion hole channel 143 is a straight line hole channel and is connected and fixed to the free section of the anchor rod; the other conversion hole 143 is a diagonal hole which is arranged corresponding to the anchor rod fixing section, and the straight line hole and the diagonal hole are not communicated.
In this embodiment, the bent portion of the anchor rod fixing section 12 is respectively connected with the protective tube 15 and the cement grout 13 through short elastic tubes, and both ends of the short elastic tubes are plugged into the protective tube and the cement grout 13 by 30 cm.
With reference to fig. 1 to 6, a further construction method for passing through a pre-embedded anchor rod connection structure under a pre-built building includes the following specific steps:
firstly, constructing foundation reinforcing piles 9 according to the design requirements of a building to be built firstly, and then pre-burying protective pipes 15 at equal intervals while constructing a mattress layer 3, wherein the intervals can be 1.2m to 2 m; at this point the building can be first constructed followed by the construction of the superstructure.
And step two, designing a construction drawing of foundation pit support according to the depth of the foundation pit on one side of the first-built building and the load condition of the first-built building, and constructing a support pile 8 according to the drawing. The anchor rod fixing section 12 and the cement grout body 13 can be constructed at the other side of the building at the same time or separately according to the design angle, and are buried in the soil body at the lower part of the existing ground 1.
In this embodiment, the length of the anchor rod fixing section 12 is 1.0-1.5 m longer than the design length during the manufacturing process, so as to satisfy the locking requirement. The spacing between the positioning frameworks is 1.5-2.0 m, and the free section 11 of the anchor rod is uniformly bundled around the positioning frameworks by iron wires. At the free section of the anchor rod fixing section 12, the free section 11 of the anchor rod is fully coated with butter and wrapped by a plastic sleeve to ensure that the free section 11 of the anchor rod is not bonded with cement paste. And slowly putting the manufactured rod body into the hole 12 of the anchor rod fixing section.
In the embodiment, the cement is P.S.A. 32.5, the water cement ratio is 0.5, after hole cleaning is finished, the grouting pipe is inserted to the bottom of the hole, and grouting is carried out by using a high-pressure pump. And (4) slowly and continuously grouting until water and impurities in the drill hole are completely replaced out of the hole and cement thick slurry flows out of the hole, and then pulling out the grouting pipe.
In the embodiment, after 7 days of anchor rod construction, the anchor is tensioned and locked. 500 kN-grade penetrating jacks are used for tensioning the anchor rods, and the tensioning equipment needs to be calibrated by a metering department before tensioning the anchor rods. And tensioning for the first time to the designed bearing capacity value of the anchor rod, unloading, tensioning for the second time and locking to the load locking value.
The engineering supporting pile 8 adopts a long spiral hole-forming concrete post-inserted bar pile-forming process, wherein a stiffening hoop forming method is adopted for manufacturing a reinforcement cage, so that the position and the angle of a reinforcement are accurate; the stiffening hoops are welded with the main bars, and the spiral hoops are firmly bound with the main bars. If the main reinforcement of the reinforcement cage has joints, when lap welding is adopted, the welding length is not less than 10d in one-side welding mode, and not less than 5d in two-side welding mode. The number of joints of the main ribs on the same section is not more than 50% of the total number of the main ribs. At least 3 groups of protective layer cushion blocks are arranged in each cage, and at least 4 blocks of each group are arranged. The steel reinforcement cage is strictly forbidden to rise and fall in the transportation and hoisting process to prevent bending deformation. When the steel reinforcement cage enters the hole, the hole site should be aligned, slowly put lightly, avoid colliding the pore wall, if meet the resistance in the lower cage in-process, must not transfer by force, should find out and continue to put the cage behind the reason.
And when concrete is poured, controlling the slump of the concrete to be 180-220 mm. And the concrete pouring is continuously carried out, the pouring is finished within the initial setting time of the concrete, the concrete pouring amount of the last time is well controlled when the pouring is about to be finished, and the over-pouring thickness is 0.5 m. And (4) making a group of test blocks for each class, performing standard maintenance for 7 days and 28 days, and sending the test blocks to a first-class test room for a compression test.
And step three, constructing the crown beam 10 and the anchoring conversion part 14, embedding the protective pipe 15 in the crown beam 10, and embedding the conversion hole 143 in the anchoring conversion part 14. The anchor rod fixing section 12 is connected with the anchor rod free section 11, and the connection position is connected through the anchoring conversion piece 14. The steel strand crosses anchor rod free segment 11 in pillar 15, and the butt joint of steel strand can adopt the joint connector, must guarantee that the steel strand leads to long the setting. One end of the anchor rod free section 11 is connected with the anchor rod fixing section 12 through an anchoring conversion part 14, and the other end of the anchor rod free section penetrates through a protection pipe 15 and is anchored on the crown beam 10; when the anchor conversion piece 14 is internally provided with an arc-shaped pore channel, the anchor rod free section 11 and the anchor rod fixed section 12 are connected in advance and temporarily fixed on the crown beam 10, and then the anchor rod free section 11 is fastened according to the anchoring requirement; when two conversion hole channels 143 are arranged in the anchoring conversion piece 14, one conversion hole channel 143 is a linear hole channel and is pre-connected with the free section of the anchor rod in a penetrating way and then fixed according to requirements; the other conversion hole 143 is a diagonal hole which is fixedly arranged corresponding to the anchor rod fixing section, and the straight hole and the diagonal hole are not communicated.
In this embodiment, to the construction of the pile head of a fender pile 8 and crown beam 10, need chisel pile head and clear soil, concrete placement 3~7 days can chisel out pile bolstering and unnecessary pile body concrete to reject the remaining concrete on the stake owner muscle, guarantee that the length that the owner muscle stretches into crown beam 10 satisfies the designing requirement, if can not satisfy the requirement, can weld the reinforcing bar with specification, intensity level. When lap welding is adopted, the welding length is not less than 10d in one-side welding and not less than 5d in two-side welding. The surface of the underground surface and the pit wall of the beam is manually cleaned to be smooth and free of soil deficiency. And then, installing the side die of the crown beam 10, wherein the joint of the die plate should not leak slurry, and water should not be accumulated in the die plate. The contact surface of the template and the concrete is cleaned and coated with the release agent, and the release agent influencing the structural performance cannot be adopted.
Step four, the joint of the anchor rod fixing section 12 and the anchor rod free section 11 is a conversion section, the anchor rod free section 11 is horizontal on the ground where the building is built in advance, and the anchor rod fixing section 12 is obliquely arranged; the transition section is connected through an anchoring transition piece 14 in a penetrating way; the length of the cross-under is not less than 20 cm.
And fifthly, detecting that the tensioning acting force of the anchor rod free section 11 meets the design requirement, constructing the foundation 2, the building, the foundation pit on one side and the auxiliary structures of the foundation pit, monitoring the stress and deformation of the excavated foundation pit, the anchor rod free section 11 and each pile body in real time, and performing early warning control in time according to the monitoring result.
In the fifth step, the detected number of the anchor rod free section 11 and/or the anchor rod fixed section 12 comprises the following prestressed anchor rods in the composite soil nailing wall: the number of the anchor rods is not less than 5% of the total number of the anchor rods, and the detection number of the anchor rod free sections 11 and/or the anchor rod fixed sections 12 in the same soil layer is not less than 3; the monitoring and early warning indexes of the anchor rod free section 11 and/or the anchor rod fixed section 12 are at least anchor rod axial force and horizontal displacement.
In the fifth step, the support piles 8 are detected by a low-strain detection method, the detection number of the low-strain method is 20 percent of the total construction pile number, and the integrity of the pile body is detected by low-strain motion of not less than 5 single projects; in addition, for the monitoring and early warning indexes of the pile body, at least the horizontal movement monitoring of the pile top, the settlement of the pile top and the horizontal displacement of the deep layer of the pile body are carried out.
In this embodiment, the monitoring of the foundation pit and the surrounding environment includes monitoring of horizontal displacement of the top of the slope, monitoring of settlement of the top of the slope, monitoring of horizontal movement of the top of the pile, monitoring of settlement of the top of the pile, monitoring of horizontal displacement of the deep layer of the pile body, monitoring of internal force of the anchor rod, and monitoring of deformation between the sales buildings of the 1#2# commercial building of the pre-built building and the sample plates. The monitoring results were as follows: the maximum value of sedimentation is 17.3mm, and the early warning value is 20 mm; the bolt axial force is 208.59-223.34 kN, and the early warning value is not less than 200 or not more than 320 kN; the maximum horizontal displacement of the deep layer is 18.1 mm. The early warning value is 20mm, and no abnormity occurs.
In this embodiment, the detection should be performed according to relevant specifications during the construction of the open groove and the underground structure, and the detection work should include the low strain method detection of the support pile 8 and the acceptance test of the prestressed anchor rod. Detecting the number of the support piles 8 by a low-strain method according to 20 percent of the total construction pile number, and carrying out low-strain dynamic detection on the integrity of a pile body of each single project by not less than 5; the anchor rod detects the prestressed anchor rod that quantity includes in the compound soil nail wall: the number of the anchor rods in the same soil layer is not less than 5% of the total number of the anchor rods, and the number of the anchor rods in the same soil layer is not less than 3. The detection result shows that the detected slope protection piles are I-type piles. In the acceptance test of 14 pre-stressed anchor rods to be tested at the part, the maximum loading is 1.3 times of the standard axial tension value Nk of the pre-stressed anchor rods to be tested. Proved by facts, the scheme saves the manufacturing cost by about more than 2000 ten thousand and saves the construction period by about more than 120 days.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that may be made by those skilled in the art within the technical scope of the present invention will be covered by the scope of the present invention.

Claims (10)

1. A pre-buried anchor rod connecting structure passing through a pre-built building is characterized by comprising a current ground (1) where one side of the pre-built building is located, a foundation pit arranged on the other side of the pre-built building, a pre-built foundation (2) connected to a soil body below the pre-built building, a pre-built mattress layer (3) connected below the pre-built foundation (2), a foundation reinforcing pile (9) connected inside the soil body below the pre-built mattress layer (3), a supporting pile (8) connected to one side of the foundation pit close to the pre-built building, a crown beam (10) connected to the top of the supporting pile (8), an anchor rod free section (11) pre-penetrated into the crown beam (10) and the pre-built mattress layer (3), an anchor rod fixing section (12) connected to the tail end of the anchor rod free section (11) and connected below the current ground (1), and an anchor conversion piece (14) connected to the joint of the anchor rod free section (11) and, and a cement grout body (13) sleeved on the periphery of the anchor rod fixing section (12);
the anchor rod free section (11) is externally connected with a protective pipe (15) in a penetrating mode, and the protective pipe (15) is embedded in the pre-built mattress layer (3) and/or the crown beam (10).
2. The pre-buried anchor rod connecting structure passing through the pre-built building according to claim 1, wherein the anchoring conversion member (14) comprises an anchoring beam (141), a supporting column (142) connected to the lower part of the anchoring beam (141), and a conversion hole channel (143) arranged inside the anchoring beam (141);
the conversion hole channel (143) is an arc-shaped hole channel, the upper end of the arc-shaped hole channel corresponds to the free section of the anchor rod, the lower end of the arc-shaped hole channel corresponds to the fixed section of the anchor rod, and the inside of the arc-shaped hole channel is a straight-in section of the free section of the anchor rod and the fixed section of the anchor rod; or two conversion pore channels (143) are provided, and one conversion pore channel (143) is a linear pore channel and is connected and fixed corresponding to the free section of the anchor rod in a penetrating way; the other conversion hole channel (143) is a diagonal hole channel, the diagonal hole channel is arranged corresponding to the anchor rod fixing section, and the straight line hole channel and the diagonal hole channel are not communicated.
3. The pre-buried anchor rod connecting structure passing through the pre-built building according to claim 1, wherein the foundation reinforcing piles (9) are arranged in a quincunx shape or a partial quincunx shape, and the bottom height of the foundation reinforcing piles (9) is lower than that of the supporting piles (8); the foundation reinforcing pile (9) comprises a CFG pile, a cast-in-situ bored pile or a precast tubular pile.
4. The pre-buried anchor rod connecting structure passing through the pre-built building according to claim 1, wherein the crown beam (10) is arranged through the top of the support pile (8), the thickness of the crown beam (10) is larger than that of the pre-built mattress layer (3) and is not smaller than 500mm, and the middle point of the crown beam (10) and the middle point of the pre-built mattress layer (3) are at the same horizontal height.
5. The pre-buried anchor rod connecting structure passing through the pre-built building according to claim 1, wherein the anchor rod free section (11) is arranged in the pre-built mattress layer (3) at intervals, and the length of the anchor rod free section (11) is larger than the horizontal distance from the crown beam (10) to the outer edge of the pre-built building; the outer end of the anchor rod free section (11) penetrates through the crown beam (10) and is connected through a fastening piece (16), and the fastening piece (16) comprises a tensioning plate and a fastening nut.
6. The pre-buried anchor rod connecting structure passing through the pre-built building according to claim 1, wherein the anchor rod fixing section (12) is obliquely arranged under the existing ground (1), and one end of the anchor rod fixing section (12) which is high is connected with the anchor rod free section (11); the connecting part of the anchor rod fixing section (12) and the anchor rod free section (11) is arc-shaped or staggered, and the connecting part is sleeved through an elastic pipe and has the length not less than 20 cm; the included angle between the anchor rod fixing section (12) and the ground where the mattress layer (3) is built in advance is not less than 15 degrees.
7. A construction method for penetrating through a pre-buried anchor rod connecting structure under a pre-built building according to any one of claims 1 to 6 is characterized by comprising the following specific steps:
step one, constructing a foundation reinforcing pile (9) according to the design requirement of a building constructed in advance, and then embedding protective pipes (15) at equal intervals while constructing a mattress layer (3), so that after the mattress layer (3) is constructed, the construction of an upper structure is continued;
secondly, designing a construction drawing of foundation pit support according to the depth of the foundation pit on one side of the first-built building and the load condition of the first-built building, and constructing a support pile (8) according to the drawing; meanwhile or separately, constructing an anchor rod fixing section (12) and a cement grouting body (13) on the other side of the building in advance according to a design angle, and burying the anchor rod fixing section and the cement grouting body in a soil body at the lower part of the existing ground (1);
constructing a crown beam (10) and an anchoring conversion part (14), embedding a protective pipe (15) in the crown beam (10), and presetting a conversion pore passage (143) in the anchoring conversion part (14); one end of the anchor rod fixing section (12) is connected with the anchor rod free section (11), and the connection part is connected through an anchoring conversion piece (14); the steel strand penetrates through the anchor rod free section (11) in the protective pipe (15), and the butt joint of the anchor rod fixing section (12) and the anchor rod free section (11) can adopt a joint connector and ensure that the steel strand is arranged in a straight-through connection length; the other end of the anchor rod free section (11) penetrates through the protective pipe (15) and is anchored on the crown beam (10);
when the anchor conversion piece (14) is internally provided with an arc-shaped pore channel, the anchor rod free section (11) and the anchor rod fixing section (12) are connected in advance and temporarily fixed on the crown beam (10), and then the anchor rod free section (11) is fastened according to the anchoring requirement; when two conversion pore channels (143) are arranged in the anchoring conversion piece (14), one conversion pore channel (143) is a linear pore channel and is pre-connected with the free section of the anchor rod in a penetrating way and then fixed according to requirements; the other conversion hole channel (143) is a diagonal hole channel, the diagonal hole channel is fixedly arranged corresponding to the anchor rod fixing section, and the straight line hole channel and the diagonal hole channel are not communicated;
fourthly, the joint of the anchor rod fixing section (12) and the anchor rod free section (11) is a conversion section, the anchor rod free section (11) is horizontal at the ground where the pre-built building is located, and the anchor rod fixing section (12) is obliquely arranged; the transition section is connected in a penetrating way through an anchoring transition piece (14); the length of the cross-under is not less than 20 cm;
and fifthly, detecting that the tensioning acting force of the anchor rod free section (11) meets the design requirement, then monitoring the stress and deformation of the excavated foundation pit, the anchor rod free section (11) and each pile body in real time, and timely early warning and controlling through the monitoring result.
8. The construction method of the pre-buried anchor rod connecting structure penetrating through the pre-built building according to claim 7, wherein for the four-step anchor rod fixing section (12), at least the horizontal anchoring length in the existing ground (1) at the end part is not less than the horizontal width of the pre-built building, the included angle between the anchor rod fixing section (12) and the ground where the pre-built mattress layer (3) is located is 15-25 degrees, and the locking value of the anchor rod fixing section (12) during tensioning is improved according to the design requirement.
9. The construction method for penetrating through the pre-buried anchor rod connecting structure under the pre-built building according to claim 7, wherein the number of the detected anchor rod free sections (11) and/or the detected anchor rod fixed sections (12) in the fifth step is not less than 5% of the total number of the anchor rods, and the number of the detected anchor rod free sections (11) and/or the detected anchor rod fixed sections (12) in the same soil layer is not less than 3; the monitoring and early warning indexes of the anchor rod free section (11) and/or the anchor rod fixing section (12) are at least axial force and horizontal displacement of the anchor rod fixing section (12).
10. The construction method for penetrating through the pre-buried anchor rod connecting structure under the pre-built building according to claim 7, wherein in the fifth step, the detection of the supporting piles (8) is carried out through a low-strain detection method, and the low-strain detection method detects that the low-strain movement detection is carried out according to the low-strain detection method, wherein the low-strain detection method detects that the number of the supporting piles is 20 percent of the total construction piles and each single project is not less than 5; in addition, for the monitoring and early warning indexes of the pile body, at least the horizontal movement monitoring of the pile top, the settlement of the pile top and the horizontal displacement of the deep layer of the pile body are carried out.
CN202110343927.5A 2021-03-30 2021-03-30 Pre-buried anchor rod connecting structure passing through pre-built building and construction method thereof Pending CN113107019A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114351655A (en) * 2021-12-09 2022-04-15 长江勘测规划设计研究有限责任公司 Construction method for raising structure of back slope limited combined gravity dam
CN115305977A (en) * 2022-07-01 2022-11-08 中冀建勘集团有限公司 Foundation reinforcement method for cliff-attached building

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012020871A1 (en) * 2012-10-24 2014-04-24 Repower Systems Se Composite structure for a pile foundation for anchoring a tower, foundation and jacket for a wind turbine, and wind turbine
CN205776250U (en) * 2016-05-27 2016-12-07 中国建筑西南勘察设计研究院有限公司 A kind of Double-row-piles Structure system being provided with dilazep anchor pattern
CN107386310A (en) * 2017-08-15 2017-11-24 广东工业大学 A kind of building supporting construction and its implementation applied to slope terrain
CN107653886A (en) * 2017-08-15 2018-02-02 广东工业大学 A kind of building supporting construction and its implementation applied to foundation ditch landform
KR20200124949A (en) * 2019-04-25 2020-11-04 주식회사 일정건설 Anchor Tension way sheathing structure and sheathing method of construction

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012020871A1 (en) * 2012-10-24 2014-04-24 Repower Systems Se Composite structure for a pile foundation for anchoring a tower, foundation and jacket for a wind turbine, and wind turbine
CN205776250U (en) * 2016-05-27 2016-12-07 中国建筑西南勘察设计研究院有限公司 A kind of Double-row-piles Structure system being provided with dilazep anchor pattern
CN107386310A (en) * 2017-08-15 2017-11-24 广东工业大学 A kind of building supporting construction and its implementation applied to slope terrain
CN107653886A (en) * 2017-08-15 2018-02-02 广东工业大学 A kind of building supporting construction and its implementation applied to foundation ditch landform
KR20200124949A (en) * 2019-04-25 2020-11-04 주식회사 일정건설 Anchor Tension way sheathing structure and sheathing method of construction

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114351655A (en) * 2021-12-09 2022-04-15 长江勘测规划设计研究有限责任公司 Construction method for raising structure of back slope limited combined gravity dam
CN115305977A (en) * 2022-07-01 2022-11-08 中冀建勘集团有限公司 Foundation reinforcement method for cliff-attached building
CN115305977B (en) * 2022-07-01 2024-06-11 中冀建勘集团有限公司 Foundation reinforcement method for cliff building

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