CN116356880A - Construction method for pipe ditch joist replacement - Google Patents
Construction method for pipe ditch joist replacement Download PDFInfo
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- CN116356880A CN116356880A CN202310387513.1A CN202310387513A CN116356880A CN 116356880 A CN116356880 A CN 116356880A CN 202310387513 A CN202310387513 A CN 202310387513A CN 116356880 A CN116356880 A CN 116356880A
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- pipe
- underpinning
- joist
- ditch
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- 238000010276 construction Methods 0.000 title claims abstract description 59
- 238000009424 underpinning Methods 0.000 claims abstract description 141
- 239000002689 soil Substances 0.000 claims abstract description 74
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims abstract description 15
- 238000013461 design Methods 0.000 claims abstract description 13
- 229910000831 Steel Inorganic materials 0.000 claims description 49
- 239000010959 steel Substances 0.000 claims description 49
- 238000000034 method Methods 0.000 claims description 33
- 230000002787 reinforcement Effects 0.000 claims description 11
- 239000003292 glue Substances 0.000 claims description 7
- 238000002347 injection Methods 0.000 claims description 2
- 239000007924 injection Substances 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 abstract description 5
- 238000009435 building construction Methods 0.000 abstract description 2
- 238000009412 basement excavation Methods 0.000 description 29
- 238000004873 anchoring Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 7
- 238000006073 displacement reaction Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 230000003014 reinforcing effect Effects 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000013439 planning Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 210000002435 tendon Anatomy 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
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Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/10—Tunnels or galleries specially adapted to house conduits, e.g. oil pipe-lines, sewer pipes ; Making conduits in situ, e.g. of concrete ; Casings, i.e. manhole shafts, access or inspection chambers or coverings of boreholes or narrow wells
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D31/00—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D31/00—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
- E02D31/08—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution against transmission of vibrations or movements in the foundation soil
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/18—Bulkheads or similar walls made solely of concrete in situ
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2250/00—Production methods
- E02D2250/0023—Cast, i.e. in situ or in a mold or other formwork
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/60—Planning or developing urban green infrastructure
Abstract
The invention discloses a construction method for a pipe ditch joist replacement beam, and particularly relates to the technical field of building construction. The invention relates to a construction method for a pipe ditch underpinning beam, which is characterized in that a plurality of enclosing structures are arranged along the periphery of a foundation pit, the pipe ditch is arranged in a semi-enclosed space formed by all the enclosing structures, and the construction method specifically comprises the following four steps: firstly, a plurality of support structures are arranged along the extending direction of a pipe ditch, all the support structures are reserved with connecting node reinforcing steel bars, and each support structure comprises a snap pile and an upright post; and then carrying out beam support and underpinning Liang Bujin and pouring, and finally digging soil under the pipe trench when the concrete strength of the underpinning beam and the beam support reaches the design strength, so that the beam support supports the pipe trench, and completing construction. According to the construction method for the pipe ditch underpinning beam, the mode that the upright posts and the underpinning beam cooperate is adopted, and the underpinning beam and the beam support for bearing the weight of the pipe ditch are effectively arranged on the peripheral side of the pipe ditch, so that the pipe ditch can be safely penetrated by an underground building, and meanwhile, the safe and stable operation of the pipe ditch is ensured.
Description
Technical Field
The invention relates to the technical field of building construction, in particular to a construction method for a pipe ditch joist replacement beam.
Background
Along with the rapid development of social economy, road traffic is developed more and more rapidly, and subway lines all over the country gradually tend to be perfect. In the subway construction process, a comprehensive pipe ditch is required to be constructed in the underground space, professional hoisting ports, detection systems and maintenance ports are established for the parts of fuel gas, communication, electric power and the like, and unified management, design and planning are carried out, so that the urban underground space is effectively utilized.
However, in the construction process, if the underground excavation and underpass mode is adopted, collapse events are easy to be caused at the comprehensive pipe ditch because of small earth covering, and when the pipeline or the road is underpass, the vault is easy to be settled, so that the pipeline is pulled to be cracked, and therefore, the underground excavation and underpass mode has extremely high requirements on excavation and support.
At present, the adopted construction method adopts an open cut scheme of reverse construction of a continuous wall, thereby avoiding the risk caused by the hidden cut. The open cut mode can enable the underground building to safely penetrate through the original pipe ditch according to the designed route so as to ensure the normal operation of the construction process, but how to protect the comprehensive pipe ditch during the construction of the underground building and ensure the safe, stable and normal use of the existing pipe ditch during the construction of the underground building is a problem to be solved urgently.
Disclosure of Invention
The invention aims to solve the problem that the safety and stability of a comprehensive pipe ditch cannot be ensured when a comprehensive pipe ditch is penetrated under an underground building design line in the prior art, and the safety and stability of the pipe ditch are improved by arranging a underpinning beam, so that a pipe ditch underpinning beam construction method is provided.
In order to achieve the above object, the present invention provides the following technical solutions:
a construction method for a pipe ditch underpinning beam is characterized in that a plurality of building enclosures are arranged around a foundation pit, the pipe ditch is arranged above the building enclosures, and the construction method specifically comprises the following steps:
step one: setting a supporting structure, and reserving a connecting node steel bar:
a plurality of supporting structures are arranged along the extending direction of the pipe ditch, the connecting node reinforcing steel bars are reserved on all the supporting structures, and the supporting structures comprise occluding piles and upright posts;
step two: and (5) binding a beam support and a joist steel bar:
the underpinning beam and the beam support are arranged above the supporting structure, and the underpinning beam steel bars are bound and then anchored with the connecting node steel bars;
step three: the underpinning beam and the beam support are poured:
the underpinning beam and the beam support steel bar are bound, concrete is poured between the underpinning beam and the beam support, the underpinning beam and the beam support are formed, and the beam support is tightly attached to the pipe ditch;
step four: the underpinning beam and the beam support concrete strength reach the design strength, excavate the soil body below the trench, make the beam support the trench, accomplish the construction.
The enclosure structure is a secant pile formed by a plurality of filling piles, and the secant pile is arranged in a pipe ditch above the enclosure structure, so that the secant pile in the enclosure structure can be fully utilized when the underpinning beam and the beam support are arranged, and the number of poured stand columns is reduced.
Before the soil body below the pipe ditch is excavated, if the first underpinning beam is directly arranged to underpin the pipe ditch according to the existing construction technology, the soil body is necessarily required to be excavated downwards from the bottom end of the pipe ditch for a distance equal to the height of the first underpinning beam, but the difficulty is high when the soil body is directly excavated downwards, and the excavation time is long. Therefore, when the pipe ditch is underpinned, the beam support and the underpinning beam are arranged into the integrated L-shaped structure, so that the pipe ditch is underpinned on the basis of reducing soil excavation of the pipe ditch before underpinning, and the L-shaped structure can limit horizontal displacement of the pipe ditch.
The newly added upright posts are coordinated with the original engagement piles to form a supporting structure, so that the supporting structure bears the weight of the pipe ditch together with the dragging and changing beam and the beam support, and the dragging and changing effect is good; before pouring the underpinning beam, anchoring the underpinning beam, the steel bars in the beam support and the reserved connection node steel bars on the supporting structure, and pouring, so that the strength of the underpinning beam is greatly improved.
According to the construction method for the pipe ditch joist, the stand columns are arranged on the peripheral sides of the pipe ditch, the integral joist and the beam support are arranged on the stand columns, and in the soil body excavation process below the pipe ditch, the load and the self weight of the pipe ditch bearing platform are gradually transferred to the joist, the beam support and the stand columns, so that the normal operation of the pipe ditch is ensured when construction is carried out nearby the pipe ditch and the underground building passes through the pipe ditch. The method adopts a mode of cooperation of the upright posts and the underpinning beams, and considers the inconvenience of excessive soil excavation under the pipe ditch, so that the underpinning beams and the beam supports for bearing the weight of the pipe ditch are arranged on the peripheral side of the pipe ditch, and the safety and stability of running of the pipe ditch are ensured while the underground building safely passes through the pipe ditch; the underpinning beam has simple structure and high safety.
More specifically, in the first step, the engagement piles are cast-in-place piles formed around the foundation pit; all the upright posts are uniformly distributed on two sides of the pipe ditch.
The foundation pit is a soil pit dug underground, and because the underground soil layer is unstable, an enclosure structure is required to be arranged to enclose the surrounding soil layer so as to keep the soil layer stable. Because there are other facilities around the foundation pit, when the building envelope is set, a plurality of building envelopes are generally set in sections. The enclosure structures are arranged at the positions, close to the side walls, of the periphery of the foundation pit, so that all the enclosure structures and other facilities around the foundation pit form a nearly closed structure, namely a semi-closed space.
The pipe trench is above the enclosure structure, four junctions are formed between the pipe trench and the enclosure structure in a plan view, and four junctions are just provided with four occluding piles. Thus, the snap-in stake is located at the junction of the trench and the enclosure.
The upright posts are arranged on two sides of the pipe ditch and are uniformly distributed in a semi-closed space formed by the enclosure structure. In order to balance the stress from the trench, all the posts should be equally spaced on both sides of the trench.
More specifically, between the first step and the second step, a pre-process step is further included, where the pre-process step includes: and (5) excavating a slope to the bottom of the pipe ditch, and supporting Shi Zuoguan Liang Jidi.
The crown beams are arranged, so that discrete piles can be combined together to act together; and meanwhile, the crown beam is also used as a bending member, and is combined with the first support to jointly ensure the integrity of the continuous wall and form a support form of the inner support.
More specifically, the pre-process further includes: chiseling the top ends of all the upright posts to the designed elevation, and exposing the connecting node reinforcing steel bars on all the upright posts; and all the occluding piles are provided with bar planting holes and bar planting.
As the upright post is poured, only the connecting node reinforcing steel bars are reserved and are not exposed outside; therefore, before the reinforcement is distributed, the upright post superfilling concrete needs to be chiseled to the designed elevation, and the chiseling is kept, so that the connection node reinforcement is exposed.
When the occluding pile and the underpinning beam are anchored, the occluding pile is an original structural foundation, so that the reinforcing steel bar needs to be planted, and the anchoring of the occluding pile and the underpinning beam is realized. When the steel bar is planted, the concrete protection layer at the joint of the occluding pile and the steel bar of the underpinning beam is required to be chiseled, the chiseling is kept, the occluding pile steel bar or the lattice column is exposed, the holes are drilled at the corresponding steel bar planting positions according to the diameters of the steel bars, and the inspection aperture and the hole depth are inspected after the drilling is completed.
More specifically, the volume of the glue injection in the bar planting hole is greater than or equal to 2/3 of that of the bar planting hole.
After the hole is drilled by the bar planting hole, the bar planting hole needs to be cleaned by compressed air, dust-free hole wall is ensured, glue is injected from the bottom of the hole, the glue gradually moves outwards until the hole is filled with 2/3 of the hole volume or the hole volume is larger than 2/3 of the hole volume, and the implanted bar can be better solidified when the bar planting hole is planted in the later stage. And finally, rotating the steel bar with the pulling resistance meeting the requirement, slowly inserting the steel bar into the bottom of the hole, and waiting for solidification.
More specifically, in the second step, the diameter of the steel bar of the underpinning beam is d, and the size of the steel bar of the underpinning beam anchored into the engagement pile is not smaller than 34d.
More specifically, in the second step, the diameter of the joist steel bar is d, and the size of the joist steel bar anchored into the upright post is not smaller than 35d.
In order to ensure an effective anchoring of the joist to the supporting structure, the rebar anchoring dimensions of the joist to the supporting structure are thus defined.
More specifically, in the second step, the beam pallet rib is finished, and the underpinning Liang Bujin is performed.
Because set up in the trench both sides when the joist beam, beam support position space is narrow and small, consequently need earlier ligature the reinforcing bar of beam support reaches the design position, then ligature the joist beam reinforcing bar.
More specifically, in the third step, a grouting pipe is reserved between the beam support and the pipe trench, and the grouting pipe is used for filling a gap between the pipe trench and the beam support.
When pouring the beam support and the underpinning beam concrete, the beam support should be clung to the pipe ditch, so that the grouting pipe can be reserved, and gaps between the pipe ditch and the beam support are filled tightly, and the underpinning is ensured to be effective.
More specifically, in the fourth step, the concrete strength of the underpinning beam and the beam support reaches the design strength, and soil bodies in the pipe ditch areas I, II, III and IV are excavated in sequence; wherein, pipe ditch lower part both sides all are provided with region I, region II and region III, and region I is located the regional II upper portion outsides of corresponding side, and region II is located the regional III upper portion outsides of corresponding side, and region I, region II and in the region III the soil body all supports the pipe ditch.
After the pouring of the beam support and the underpinning beam is finished, the soil body under the pipe trench is mainly used for bearing the self weight of the pipe trench. And after the soil body is excavated, the pipe trench falls onto the beam support, so that underpinning is realized. In order to prevent the pipe ditch from being inclined in the process of excavating soil under the pipe ditch, firstly excavating soil on two sides of the pipe ditch in the soil excavating process, and then symmetrically excavating soil under the pipe ditch, namely: and excavating soil bodies in the pipe ditch areas I, II, III and IV in sequence.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the construction method for the pipe ditch underpinning beam, the upright posts are arranged on the peripheral side of the pipe ditch, the underpinning beam and the beam support are further arranged, and the self weight of the pipe ditch is gradually transferred to the underpinning beam and the beam support in the soil body excavation process under the pipe ditch, so that the construction nearby the pipe ditch and the safe and stable operation of the pipe ditch when the underground building safely passes through the pipe ditch are ensured.
2. According to the construction method for the pipe ditch underpinning beam, the node steel bars and the steel bars of the underpinning beam are anchored and then are poured, the intensity of the underpinning beam after pouring is higher, the connection intensity with the supporting structure is better, and the overall safety is enhanced.
3. The invention discloses a construction method for underpinning a beam of a pipe ditch, which is characterized in that the underpinning of the pipe ditch is carried out under the condition that no beam support is arranged in the prior art, so that the problems of excessive excavation of soil body at the bottom, high construction difficulty and long time consumption during excavation are solved, the beam support is arranged, and the underpinning of the pipe ditch is realized by combining with the underpinning beam, so that the soil body excavated before underpinning is effectively reduced, and the construction efficiency is improved.
Description of the drawings:
FIG. 1 is a flow chart of the steps of a method for constructing a tube trench joist;
FIG. 2 is a schematic structural view of a construction method of a pipe ditch joist replacement beam;
FIG. 3 is a schematic diagram showing a structure of a step 1 of the embodiment of the present invention;
FIG. 4 is a schematic diagram of a second structure of the step in the embodiment 1 of the present invention;
FIG. 5 is a schematic diagram showing a third step of the embodiment 1 of the present invention;
FIG. 6 is a schematic view of the anchoring structure of the upright post and the joist in the construction method of the joist of the pipe trench;
FIG. 7 is a schematic diagram of a structure of a tendon placement hole in a construction method of a pipe trench joist;
FIG. 8 is a schematic view of a construction method of a pipe trench joist exchange beam according to the present invention, wherein the construction method includes the steps of pile engagement and joist exchange beam anchoring;
FIG. 9 is a schematic diagram of a prior art construction for channel replacement by providing a replacement beam;
FIG. 10 is a schematic diagram of a construction method for underpinning a pipe trench according to the present invention;
FIG. 11 is a schematic diagram of the soil excavation sequence under a trench according to the present invention;
FIG. 12 is a schematic view of the structure of the trench under the trench in which the excavation is completed;
fig. 13 is a schematic structural view of the present invention after all soil excavation under the trench is completed.
The marks in the figure: the pile comprises a 1-pipe ditch, a 2-supporting structure, 21-occluding piles, 22-upright posts, 3-beam supports, 4-underpinning beams, 5-enclosure structures, 6-reinforcement planting holes, 7-ground, 8-soil mass, 9-first underpinning beams and 10-first upright posts.
Detailed Description
The present invention will be described in further detail with reference to test examples and specific embodiments. It should not be construed that the scope of the above subject matter of the present invention is limited to the following embodiments, and all techniques realized based on the present invention are within the scope of the present invention.
Example 1
The invention relates to a construction method of a pipe ditch joist, which is characterized in that a combination of an upright post 22 and a joist 4 is arranged under a pipe ditch 1, so that the safety and stability of the pipe ditch 1 are ensured when the pipe ditch 1 is penetrated under an underground building design line.
When the pipe ditch 1 is underpinned, the soil body 8 below the pipe ditch 1 is in a state of not being excavated, if the first underpinning beam 9 is directly arranged to underpin the pipe ditch 1 according to the existing construction technology, then the soil body 8 is necessarily required to be excavated downwards from the bottom end of the pipe ditch 1 for a distance which is equal to the height of the first underpinning beam 9, but the difficulty is greater when the soil body 8 is excavated downwards, and the excavation time is longer.
Therefore, when the pipe ditch 1 is underpinned, the beam support 3 is arranged, the beam support 3 and the underpinning beam 4 are arranged into an integrated L-shaped structure, the excavation amount of soil body 8 under the pipe ditch 1 before underpinning is reduced, the pipe ditch 1 is underpinned, the operation safety in later period of underpinning and pipe ditch 1 penetrating is ensured, and the L-shaped structure can limit the horizontal displacement of the pipe ditch 1.
The whole structure for realizing the underpinning of the pipe ditch 1 is specifically as follows: the utility model provides a device for underpinning pipe ditch 1, includes a plurality of bearing structure 2 of evenly locating pipe ditch 1 both sides, has set firmly the underpinning piece of L type on the bearing structure 2, and the underpinning piece of its L type is laminated mutually with the bottom and the side of pipe ditch 1 simultaneously. The L-shaped underpinning piece comprises a beam support 3 attached to the bottom end of the pipe ditch 1 and an underpinning beam 4 attached to the side surface of the pipe ditch 1.
The construction method of the device for underpinning the pipe ditch 1 is as shown in fig. 1, and comprises the following specific steps:
step one: determining a snap pile 21 according to the foundation pit and the auxiliary structure;
according to foundation pit and accessory facility construction, before the pouring of the underpinning beam 4 is carried out on the pipe ditch 1, the cast-in-place pile with the enclosure structure 5 arranged near the pipe ditch 1 can be used as a supporting point for later pouring of the underpinning beam 4.
As shown in fig. 2 and 3, when the enclosure structures 5 are disposed around the foundation pit, the enclosure structures 5 are disposed around the foundation pit at positions close to the side walls, so that a semi-enclosed space is formed by all the enclosure structures 5 and the rest of facilities around the foundation pit. When the pipe ditch 1 is above the enclosing structure 5, the pipe ditch 1 and the enclosing structure 5 form four junctions when seen downwards from the pipe ditch 1, and the four junctions are provided with one biting pile 21. Thus, the snap piles 21 are located at the junction of the trench 1 and the envelope 5.
Step two: setting upright posts 22, finishing setting a supporting structure 2, and reserving connecting node reinforcing steel bars;
as shown in fig. 4, in order to balance the stress from the trench 1, all the columns 22 should be equally spaced on both sides of the trench 1 and placed in the semi-enclosed space formed by the enclosure structure 5, while node steel bars are provided in the support structure 2.
Step three: binding reinforcing steel bars of the beam support 3 and the underpinning beam 4;
as shown in fig. 5, the underpinning beam 4 and the beam support 3 framework which are used for binding the reinforcing steel bars are arranged above the supporting structure 2, and the reinforcing steel bars bound by the underpinning beam 4 are anchored with the reinforcing steel bars of the connecting nodes;
the operation steps of the reinforcement distribution and the anchoring comprise the following steps:
s1: slope excavation is carried out to the bottom of the pipe ditch 1, and Shi Zuoguan Liang Jidi is supported;
setting a crown beam, and combining discrete piles to act together; and meanwhile, the crown beam is also used as a flexural member and combined with the first support to jointly ensure the integrity of the continuous wall, so that the support form of the inner support is formed.
S2: chiseling the top ends of all the upright posts 22 to the designed elevation, and exposing the connecting node reinforcing steel bars on all the upright posts 22;
as shown in fig. 6, since the upright 22 is cast, only the connection node reinforcing bars are reserved and are not exposed outside; therefore, before the reinforcement is laid, the upright post 22 needs to be chiseled to the designed elevation, and the chiseling is kept, so that the connection node reinforcement is exposed. And then anchoring, if the diameter of the steel bar of the underpinning beam 4 is d, in order to ensure effective anchoring of the underpinning beam 4 and the supporting structure 2, the size of the steel bar of the underpinning beam 4 anchored into the upright 22 should be not less than 35d.
S3: the bar planting holes 6 are arranged on all the occluding piles 21 and bars are planted;
when the engagement pile 21 is anchored with the underpinning beam 4, the engagement pile 21 is an original structural foundation, so that reinforcement needs to be planted, and the anchoring of the engagement pile 21 and the underpinning beam 4 is achieved. When the steel bar is planted, the concrete protection layer at the joint of the occluding pile 21 and the steel bar of the underpinning beam 4 is required to be chiseled, the chiseling is kept, the steel bar or the lattice column of the occluding pile 21 is exposed, as shown in fig. 7, holes are drilled at the corresponding steel bar planting positions according to the diameters of the steel bars, and after the drilling is completed, the inspection aperture and the hole depth are inspected.
After the hole of the bar planting hole 6 is drilled, the bar planting hole 6 needs to be cleaned by compressed air, dust-free hole wall is ensured, glue is adopted to start injecting glue from the bottom of the hole, the glue gradually moves outwards until the hole is filled with 2/3 of the hole volume or the hole is larger than 2/3 of the hole volume, and the implanted steel bar can be better solidified when the bar planting in the later stage is ensured. And finally, rotating the steel bar with the pulling resistance meeting the requirement, slowly inserting the steel bar into the bottom of the hole, and waiting for solidification.
As shown in fig. 8, after the reinforcement bar is cured, if the diameter of the reinforcement bar of the underpinning beam 4 is d, in order to ensure effective anchoring of the underpinning beam 4 and the supporting structure 2, the size of the reinforcement bar of the underpinning beam 4 anchored into the snap pile 21 should be not less than 34d.
S4: ending the beam bracket 3 to distribute the ribs, and carrying out underpinning the beam 4 to distribute the ribs;
because the space of the beam support 3 is narrow when the underpinning beams 4 are arranged on two sides of the pipe trench 1, the steel bars of the beam support 3 need to be bound to the design position firstly, and then the steel bars of the underpinning beams 4 need to be bound.
Step four: pouring concrete in the steel reinforcement cage after the joist 4 and the beam support 3 are bound;
pouring a underpinning beam 4 and a beam support 3, wherein the beam support 3 is tightly attached to the pipe ditch 1; therefore, grouting pipes can be reserved, so that gaps between the dense pipe ditches 1 and the beam supports 3 are filled, and the support is ensured to be effective.
Step five: when the concrete strength of the underpinning beam 4 and the beam support 3 reaches the design strength, excavating soil body 8 below the pipe ditch 1, so that the beam support 3 supports the pipe ditch 1, and completing construction:
the two sides of the lower part of the pipe ditch 1 are respectively provided with a region I, a region II and a region III, wherein the region I is positioned at the outer side of the upper part of the region II corresponding to the side, the region II is positioned at the outer side of the upper part of the region III corresponding to the side, soil bodies 8 in the region I, the region II and the region III are respectively used for supporting the pipe ditch 1, and soil bodies 8 under the pipe ditch 1 are sequentially excavated according to the sequence of the region I, the region II, the region III and the region IV.
As shown in fig. 11, in the process of sequentially excavating soil bodies 8 in the areas i, ii and iii, the weight of the pipe ditch 1 is gradually transferred to the beam support 3 and the underpinning beam 4, after the soil bodies 8 in the areas i, ii and iii are excavated, the soil bodies 8 do not support the pipe ditch 1 any more, and the load on the pipe ditch 1 is completely transferred to the beam support 3, so that the underpinning is completed; and then excavating the soil body 8 in the region IV, and completing the excavation of all the soil bodies 8 under the pipe ditches 1.
The construction method of the pipe ditch 1 underpinning beam 4 is that the newly added upright post 22 is coordinated with the original occluding pile 21 to form the supporting structure 2, so that the supporting structure and the dragging beam 4 bear the load of the pipe ditch 1 together, and the dragging effect is good; simultaneously, before pouring the underpinning beam 4, anchoring the steel bars in the underpinning beam 4 and the reserved connection node steel bars on the supporting structure 2, and then pouring, thereby greatly improving the strength of the underpinning beam 4.
The beneficial effects of this embodiment are: according to the construction method for the pipe ditch underpinning beam, the upright posts 22 are arranged on the peripheral side of the pipe ditch 1, the underpinning beam 4 and the beam support 3 are arranged, and the load of the pipe ditch 1 is gradually transferred to the underpinning beam 4 and the beam support 3 in the soil body 8 excavation process in a mode that the upright posts 22 and the underpinning beam 4 cooperate, so that the safe and stable operation of the pipe ditch 1 is ensured when the underground building safely passes through the pipe ditch 1 after the soil body 8 excavation is finished.
Example 2
When the underground construction passes through the pipe ditch 1, the soil body 8 below the pipe ditch 1 needs to be excavated. Therefore, before the excavation, the structural support needs to be arranged below the pipe ditch 1 to bear the load of the pipe ditch 1, if the first underpinning beam 9 is directly arranged according to the prior art, the whole underpinning structure needs to be placed below the pipe ditch 1, which can lead to more soil body excavated before the underpinning is completed.
After all the ditches 1 are excavated from the ground 7 by adopting an open cut method, the ditches 1 are underpinned. As shown in fig. 9, if the first underpinning beam 9 is only provided according to the conventional construction method, if the height of the first underpinning beam 9 is 1500mm, that is, the height of the soil body under the trench 1 needs to be excavated before the first underpinning beam 9 is constructed, this will cause more excavation of the soil body 8 under the trench 1, which is easy to cause instability of the structure of the trench 1, and the first underpinning beams 9 are all located under the trench 1, which cannot limit the displacement of the trench 1 in the horizontal direction. Meanwhile, in the case where only the first underpinning beam 9 is provided, the first upright 10 required to be chiseled has a large concrete portion, and the construction efficiency is also lowered.
The pipe trench 1 was thus replaced by the construction method according to example 1 of the present invention. According to embodiment 1, a device for underpinning a pipe trench 1 is obtained, which comprises a plurality of support structures 2 which are respectively arranged at two sides of the pipe trench 1, and two underpinning pieces which are fixedly arranged on the support structures 2 at two sides and face opposite, wherein the whole cross section of each underpinning piece is L-shaped, the length of each underpinning piece is matched with the pipe trench 1, the device comprises a beam support 3 and an underpinning beam 4, the pipe trench 1 is arranged between the two underpinning pieces which face opposite, the beam support 3 is attached to the bottom end of the pipe trench 1, and the underpinning beam 4 is attached to the side face of the pipe trench 1. The underpinning principle is that after the whole device is set, in the process that the soil body 8 which is supported under the pipe ditch 1 is excavated, the beam support 3 arranged under the pipe ditch 1 gradually bears the weight of the pipe ditch 1, so that the underpinning of the pipe ditch 1 is realized.
As shown in fig. 10, when the underpinning device is arranged to underpin the pipe trench 1 according to the construction method of the present invention, if the height of the underpinning beam 4 is 1500mm and the height of the beam support 3 is 300mm, the height of the soil body below the excavated pipe trench 1 is only the height of the beam support 3, that is, 300mm in the construction process of the underpinning pipe trench 1. Therefore, the soil body excavated before underpinning can be effectively reduced after the beam supports 3 are arranged.
According to the device for underpinning the pipe trench 1, after construction is finished, the underpinning process of the beam support 3 for supporting the pipe trench 1 is realized in the process of soil excavation under the pipe trench 1.
The device for underpinning the pipe ditch 1 comprises the following construction steps:
1. a rotary drilling hole forming mode is adopted, and a construction supporting structure 2 is poured;
2. excavating soil downwards from the ground 7 until the top end of the soil 8 is flush with the bottom end of the pipe ditch 1;
3. determining the height and the width of the beam support 3, excavating a soil body 8 positioned below the pipe ditch 1 along the bottom end of the pipe ditch 1 until the excavated space meets the size requirement of the beam support 3;
4. chiseling part of concrete of the supporting structure 2 until the connecting node reinforcing steel bars are exposed;
5. setting a template, binding 3 steel bars of a beam support and 4 steel bars of a joist, and pouring:
as shown in fig. 10, in the process of distributing the ribs, the beam support 3 and the underpinning beam 4 are integrally arranged, that is, the beam support 3 and the underpinning beam 4 are integrated in the binding and pouring process of the reinforcing steel bars. However, under the influence of space, a mode of binding the steel bars of the beam support 3 and then binding the steel bars of the underpinning beam 4 is generally adopted, and when casting, the beam support 3 is cast firstly and then the underpinning beam 4 is cast. After casting and forming, the cross sections of the obtained underpinning beam 4 and the beam support 3 along the height direction are L-shaped.
6. After the poured beam support 3 and the underpinned beam concrete reach the design strength, excavating a soil body 8 under the pipe ditch 1, and after the soil body 8 is excavated, removing the template:
the pipe ditch 1 lower part both sides all are provided with region I, region II and region III, and region I is located the regional II upper portion outsides of corresponding side, and region II is located the regional III upper portion outsides of corresponding side, and region I, regional II and regional III's soil body all support pipe ditch 1.
As shown in fig. 11, when pouring of the beam support 3 and the underpinning beam 4 is completed, the soil bodies 8 on two sides of the pipe ditch 1 are firstly excavated when the concrete strength reaches the design strength, then the soil bodies 8 on two sides of the lower part of the pipe ditch 1 are excavated, after the excavation of the soil bodies I on two sides of the lower part of the pipe ditch 1 is completed, the soil bodies II on two sides of the lower part of the pipe ditch 1 are excavated, then the soil bodies III on the lower part of the pipe ditch 1 are excavated, the self weight of the pipe ditch 1 and the load born by the self weight of the pipe ditch 1 are gradually acted on the beam support 3 in the process of sequentially excavating the region I, the region II and the region III, then the force of the beam support 3 is transferred to the underpinning beam 4, the underpinning beam 4 is transferred to the supporting structure 2, the underpinning of the soil bodies 8 in the region I, the soil bodies II and the soil bodies in the region III are not supported on the pipe ditch 1 any more after the excavation of the soil bodies in the region I, the region II and the soil bodies III is completed. In the excavation process, the mode of gradually excavating from two sides towards the middle is selected, so that the pipe ditch 1 is prevented from being overturned towards the side to a certain angle due to more excavation of one side, and the pipe ditch 1 is prevented from being damaged due to torsion.
Finally, excavating soil body 8 in the region IV. And in the process of pouring concrete between the beam support 3 and the underpinning beam 4, setting templates according to requirements, if the templates are set between the non-excavated earthwork area and the beam support 3 before pouring, the templates are not immediately taken out after pouring is finished, and the templates can be taken out after the excavation of all soil bodies 8 below the pipe trench 1 is finished in the later stage.
After the soil body 8 below the pipe ditch 1 is excavated, the structure is shown in fig. 13.
The beneficial effects of this embodiment are: according to the construction method for the underpinning beam of the pipe ditch, disclosed by the invention, the soil body 8 needing to be excavated before underpinning is reduced, the integral structure of the underpinning beam 4 and the beam support 3 is arranged on the basis of reducing the excavation of the soil body 8 below the pipe ditch 1, and along with the excavation process of the soil body below the pipe ditch 1, the load of the pipe ditch 1 is transferred to the underpinning beams 4 positioned on two sides of the pipe ditch through the beam support 3, so that the normal operation of the function of the pipe ditch 1 when the pipe ditch 1 is penetrated under a underground building is ensured, and meanwhile, the L-shaped structure formed by the beam support 3 and the underpinning beam 4 can also limit the horizontal displacement of the pipe ditch 1.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (10)
1. The construction method for the pipe ditch underpinning beam is characterized in that a plurality of building enclosures (5) are arranged along the periphery of a foundation pit, and a pipe ditch (1) is arranged above the building enclosures (5), and specifically comprises the following steps:
step one: setting a supporting structure (2), and reserving a connecting node steel bar:
a plurality of supporting structures (2) are arranged along the extending direction of the pipe ditch (1), the connecting node reinforcing steel bars are reserved on all the supporting structures (2), and the supporting structures (2) comprise occluding piles (21) and upright posts (22);
step two: beam support (3) and underpinning roof beam (4) steel bar ligature:
the underpinning beam (4) and the beam support (3) are arranged above the supporting structure (2), and the steel bars of the underpinning beam (4) are bound and then anchored with the connecting node steel bars;
step three: the underpinning beam (4) and the beam support (3) are poured:
the steel bars of the underpinning beam (4) and the beam support (3) are bound, concrete of the underpinning beam (4) and the beam support (3) is poured, the underpinning beam (4) and the beam support (3) are formed, and the beam support (3) is tightly attached to the pipe ditch (1);
step four: the concrete strength of the underpinning beam (4) and the beam support (3) reaches the design strength, soil bodies (8) below the pipe ditches (1) are excavated, so that the beam support (3) supports the pipe ditches (1), and construction is completed.
2. The method according to claim 1, wherein in the first step, the engagement piles (21) are cast-in-place piles formed around the foundation pit; all the upright posts (22) are uniformly distributed on two sides of the pipe ditch (1).
3. The method of constructing a replacement beam for a pipe ditch according to claim 1, further comprising a pre-process step between the first step and the second step, the pre-process step comprising: and (5) excavating a slope to the bottom of the pipe ditch (1), and supporting Shi Zuoguan Liang Jidi.
4. A method of constructing a replacement beam for a pipe ditch according to claim 3, wherein the pre-process further comprises: chiseling the top ends of all the upright posts (22) to a designed elevation, and exposing the connecting node reinforcing steel bars on all the upright posts (22); and all the occluding piles (21) are provided with the bar planting holes (6) and planted with bars.
5. The construction method of the pipe ditch joist according to claim 4, wherein the volume of the glue injection in the bar planting hole (6) is larger than or equal to 2/3 of the bar planting hole (6).
6. The construction method of the pipe ditch joist according to claim 1, wherein in the second step, the diameter of the steel bar of the joist (4) is d, and the size of the steel bar of the joist (4) anchored into the engagement pile (21) is not smaller than 34d.
7. The construction method of a pipe ditch joist according to claim 1, wherein in the second step, the diameter of the steel bar of the joist (4) is d, and the size of the steel bar of the joist (4) anchored into the upright post (22) is not less than 35d.
8. The construction method for the pipe trench joist according to claim 1, wherein in the second step, the joist (3) is finished in the reinforcement arrangement, and the joist (4) is reinforced.
9. The method according to any one of claims 1-8, wherein in the third step, a grouting pipe is reserved between the beam support (3) and the pipe trench (1), and the grouting pipe is used for filling a gap between the pipe trench (1) and the beam support (3).
10. The construction method of the pipe ditch joist according to any one of claims 1 to 8, wherein in the fourth step, the concrete strength of the joist (4) and the joist support (3) reaches the design strength, soil bodies (8) in an area i, an area ii, an area iii and an area iv under the pipe ditch (1) are sequentially excavated, wherein the two sides of the lower part of the pipe ditch (1) are respectively provided with the area i, the area ii and the area iii, the area i is located at the upper outer side of the area ii on the corresponding side, the area ii is located at the upper outer side of the area iii on the corresponding side, and the soil bodies (8) in the area i, the area ii and the area iii all support the pipe ditch (1).
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| CN109403654A (en) * | 2018-11-05 | 2019-03-01 | 广东赛力克建筑技术工程有限公司 | A kind of underpinning method of existing building structure |
| CN110670615A (en) * | 2019-09-24 | 2020-01-10 | 天津大学 | Subway green construction adjustment method based on limited space |
| CN112176879A (en) * | 2020-10-15 | 2021-01-05 | 深圳市罗湖建筑安装工程有限公司 | Bridge pier foundation underpinning structure and construction method |
| CN112411610A (en) * | 2020-10-30 | 2021-02-26 | 中铁五局集团有限公司 | Pile foundation underpinning construction method |
| CN112411613A (en) * | 2020-10-30 | 2021-02-26 | 中铁五局集团有限公司 | Underpinning beam construction method in pile foundation underpinning construction |
| CN115949091A (en) * | 2022-11-21 | 2023-04-11 | 山东大学 | Pile foundation structure and method suitable for underpinning pile foundation of pile-falling tunnel |
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2023
- 2023-04-12 CN CN202310387513.1A patent/CN116356880B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109403654A (en) * | 2018-11-05 | 2019-03-01 | 广东赛力克建筑技术工程有限公司 | A kind of underpinning method of existing building structure |
| CN110670615A (en) * | 2019-09-24 | 2020-01-10 | 天津大学 | Subway green construction adjustment method based on limited space |
| CN112176879A (en) * | 2020-10-15 | 2021-01-05 | 深圳市罗湖建筑安装工程有限公司 | Bridge pier foundation underpinning structure and construction method |
| CN112411610A (en) * | 2020-10-30 | 2021-02-26 | 中铁五局集团有限公司 | Pile foundation underpinning construction method |
| CN112411613A (en) * | 2020-10-30 | 2021-02-26 | 中铁五局集团有限公司 | Underpinning beam construction method in pile foundation underpinning construction |
| CN115949091A (en) * | 2022-11-21 | 2023-04-11 | 山东大学 | Pile foundation structure and method suitable for underpinning pile foundation of pile-falling tunnel |
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