Foundation pit supporting anchor rod construction structure
By installing inclined sleeves and water-stop structures inside the anchor bolt holes, the problem of sand inrush during anchor bolt construction was solved, achieving simple and effective sand inrush control and ensuring the safety of the foundation pit.
Patent Information
- Application Number
- CN202422451334.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-10-10
AI Technical Summary
In soft and complex strata, especially in high-water-head silty sand interlayers, the tidal influence during anchor bolt construction can cause sand inrush, which can easily lead to soil erosion and foundation pit collapse.
The system employs an inclined casing and water-stopping structure. The casing extends inside the anchor bolt hole to increase the height and angle of sand inflow, and seals the sand inflow channel through anchor cables and expansion water-stopping strips. Gravity is used to reduce sand inflow, and the casing is reusable.
It effectively prevents sand from gushing out, is simple and quick to construct, does not affect subsequent processes, reduces construction costs, and improves the safety of the foundation pit.
Smart Images
Figure CN223660842U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model is used in the field of building construction, in particular to a foundation pit support anchor rod construction structure. BACKGROUND
[0002] The wide application of anchor rods brings more choices to the design of foundation pit support. Compared with internal support, the type of pile-anchor support provides convenient construction conditions for subsequent construction. In the construction process, the reliability of the working performance of the anchor rod determines the safety of the foundation pit support. In particular, when the anchor rod anchoring section is in soft and complex stratum, such as high water head silt sand interlayer, the water-rich sand layer flows more due to the influence of tides during anchor rod construction. Therefore, a large amount of sand gushing will easily cause soil erosion and collapse due to tides when drilling and anchor cable locking, which eventually causes the collapse of the foundation pit. SUMMARY
[0003] The utility model discloses a foundation pit support anchor rod construction structure which can effectively guide the direction and height of sand gushing and effectively prevent sand layer from gushing.
[0004] The utility model discloses a technical scheme adopted to solve the technical problems:
[0005] A foundation pit support anchor rod construction structure, comprising a sleeve and a support pile distributed along the circumference of the foundation pit, the support pile is provided with an anchor rod hole extending from the inner side of the foundation pit to the outer side of the foundation pit, the anchor rod hole is inclinedly arranged, one end of the anchor rod hole at the inner side of the foundation pit is higher than the other end at the outer side of the foundation pit, the sleeve is inserted into the anchor rod hole, one end of the sleeve is inclinedly extended upward into the inner side of the foundation pit, the other end of the sleeve is inclinedly extended downward into the soil body outside the foundation pit.
[0006] In some implementations, a water stop structure is arranged between the sleeve and the hole wall of the anchor rod hole.
[0007] In some implementations, the water stop structure comprises geotextile and expansion water stop tape.
[0008] In some implementations, an anchor cable is further included, the anchor cable is arranged in the sleeve, and the length of the anchor cable is greater than the length of the sleeve and extends into the soil body outside the foundation pit.
[0009] In some implementations, one end of the anchor cable extending into the soil body outside the foundation pit is provided with an anchor disc.
[0010] In some implementations, a plurality of anchor cables are arranged, the plurality of anchor cables extend along the length direction, and the plurality of anchor cables are arranged in a straight line.
[0011] In combination with the above implementation manner, in some implementation manners, one end of the anchor cable located inside the foundation pit is provided with an expansion water stop.
[0012] In combination with the above implementation manner, in some implementation manners, the length of the sleeve pipe extending into the inside of the foundation pit is not less than 2 meters.
[0013] In combination with the above implementation manner, in some implementation manners, the sleeve pipe is a metal round pipe.
[0014] One of the above technical solutions has at least one of the following advantages or beneficial effects: in the technical solution of the utility model, the sleeve pipe is added at the anchor rod hole position of the support pile to play a drainage role, the sleeve pipe extends along the direction of the anchor rod hole for a certain length, the sleeve pipe can effectively increase the height and length of the anchor rod hole at one end inside the foundation pit, the sand gushing height and angle are increased, and the self sand gushing is reduced under the action of gravity; the sleeve pipe can be pulled out after the anchor rod construction to be reused. The foundation pit support anchor rod construction structure can effectively guide the sand gushing direction and height, effectively prevent the sand layer from gushing out, and the construction process is easy, simple, fast, and does not affect subsequent anchoring, grouting, and crown beam construction processes.
[0015] The additional aspects and advantages of the utility model will be partially given in the following description, some will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS
[0016] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:
[0017] Figure 1 is a structural elevation view of one embodiment of the utility model;
[0018] Figure 2 is Figure 1 a structural sectional view of one embodiment shown. DETAILED DESCRIPTION
[0019] This part will describe the specific embodiments of the utility model in detail, the preferred embodiments of the utility model are shown in the drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the utility model, but it cannot be understood as the limitation of the protection scope of the utility model.
[0020] In the utility model, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the utility model, and is not indicative or suggestive of the technical features indicated must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as the limitation of the utility model.
[0021] In the utility model, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and "greater than", "less than", "exceed" and the like are understood as not including the number; "and above", "and below", "and within" and the like are understood as including the number. In the description of the utility model, if "first" and "second" are described, they are only used for distinguishing technical features for the purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.
[0022] In the utility model, unless otherwise explicitly limited, the words "arrange", "install", "connect" and the like should be understood in a broad sense, for example, can be directly connected, can also be indirectly connected through an intermediate medium; can be fixedly connected, can also be detachably connected, can also be integrally formed; can be mechanically connected, can also be electrically connected or capable of communicating with each other; can be the communication or interaction relationship between two elements inside or two elements. The person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.
[0023] Among them, Figure 1 The reference direction of the embodiment of the utility model is given, and the embodiment of the utility model is described below in combination with the direction shown in the figure. Figure 1
[0024] The embodiment of the utility model provides a foundation pit support anchor rod construction structure, which can be used for large-diameter reinforced rotary excavating pile anchor rod construction under the tidal environment of water-rich sand layer at the river bank, solves the anchor cable construction system of large-diameter reinforced rotary excavating pile anchor rod in water-rich sand layer construction due to tide. As a construction technology for protecting the safety of foundation pit, the anchor rod is usually 150mm, but compared with the complex soil environment, a large-diameter reinforced rotary pile anchor rod needs to be used, but due to the complexity of the soil environment, the situation encountered is different, and water and soil loss causes foundation pit collapse, which is a common situation. According to the current technology, more post-control is adopted, that is, grouting backfill is carried out after sand gushing occurs or grouting backfill is carried out when the lower limit of the periphery appears, which is easy to cause certain damage to the foundation pit. The technical scheme of the utility model can achieve pre-control, the cost is not high and the construction is simple.
[0025] Referring to Figure 1 , The foundation pit supporting anchor rod construction structure comprises a sleeve pipe 100 and supporting piles 200 distributed along the periphery of the foundation pit, the supporting piles 200 are formed by drilling along the periphery of the foundation pit and then pouring concrete, the supporting piles 200 can bear the earth pressure outside the foundation pit and prevent the collapse of the side wall of the foundation pit. The supporting pile 200 is provided with an anchor rod hole 201 extending from the inside of the foundation pit to the outside of the foundation pit, the anchor rod hole 201 is an opening in the supporting pile 200 for pouring the anchor rod, the anchor rod hole 201 is formed by drilling after the supporting pile 200 is formed, the anchor rod hole 201 is obliquely arranged, one end of the anchor rod hole 201 at the inside of the foundation pit is higher than the other end at the outside of the foundation pit, the sleeve pipe 100 is inserted into the anchor rod hole 201, in order to effectively increase the sand gushing height, the sleeve pipe 100 extends along the anchor rod hole, the sleeve pipe 100 needs to have a certain length, for example, 6 meters, one end of the sleeve pipe 100 obliquely extends upwards into the inside of the foundation pit, and the other end of the sleeve pipe 100 obliquely extends downwards into the soil body outside the foundation pit.
[0026] In the technical scheme of the utility model, the sleeve pipe 100 is added at the position of the anchor rod hole 201 of the supporting pile 200 to play a drainage role, the sleeve pipe 100 can effectively increase the height and length of one end of the anchor rod hole at the inside of the foundation pit, the sand gushing height and angle are increased, and the self sand gushing is reduced under the action of gravity; the sleeve pipe 100 can be pulled out after the anchor rod is constructed, so that the sleeve pipe 100 can be repeatedly used. The foundation pit supporting anchor rod construction structure can effectively guide the sand gushing direction and height, effectively prevent the sand layer from gushing out, and is easy, simple, quick in construction, and does not affect subsequent anchoring, grouting, and crown beam construction processes.
[0027] In some embodiments, referring to Figure 1 , Figure 2 A water stop structure 300 is arranged between the sleeve pipe 100 and the hole wall of the anchor rod hole 201, and the water stop structure 300 is arranged at the gap between the sleeve pipe 100 and the anchor rod hole 201 to further prevent sand gushing.
[0028] In some embodiments, the water stop structure 300 comprises geotextile and an expansion water stop belt. The gap between the sleeve pipe 100 and the anchor rod hole 201 is blocked by the geotextile and the expansion water stop belt, and the use is convenient.
[0029] In some embodiments, referring to Figure 1 , Figure 2 The foundation pit supporting anchor rod construction structure further comprises an anchor cable 400, the anchor cable 400 is a prestressed anchor cable 400 for the anchor rod, the anchor cable 400 is arranged in the sleeve pipe 100, and the length of the anchor cable 400 is greater than that of the sleeve pipe 100 and extends into the soil body outside the foundation pit.
[0030] Further, referring to Figure 1 , Figure 2 One end of the anchor cable 400 extending into the soil body outside the foundation pit is provided with an anchor disc 401, and the anchor disc 401 at the end part effectively increases the anchoring capacity of the anchor cable 400 at the end part.
[0031] wherein, referring to Figure 1 , Figure 2 , the anchor cable 400 is provided in plurality, the plurality of anchor cables 400 extends along the length direction, and the plurality of anchor cables 400 is arranged in straightness.
[0032] In some embodiments, referring to Figure 2 , the anchor cable 400 is provided with an expansion water stop 402 at one end inside the foundation pit. The expansion water stop 402 is used to wrap the anchor cable 400 after the casing 100 is pulled out, so as to close the hole and avoid sand gushing.
[0033] In some embodiments, referring to Figure 1 , the casing 100 extends into the inside of the foundation pit with a length of not less than 2 meters. The height of sand gushing is increased as much as possible, so as to reduce the self sand gushing under the action of gravity.
[0034] In some embodiments, the casing 100 adopts a metal round pipe. On the one hand, the metal round pipe can be reused, and on the other hand, the form of the round pipe is also helpful for inserting and pulling in the anchor rod hole and drilling and grouting therein.
[0035] In order to better understand the technical scheme of the utility model, a specific construction step of an embodiment is provided:
[0036] Construction sequence: drilling machine is in place and hole is opened → casing 100 is inserted → soil cloth + expansion water stop 402 is used to fill the gap between the hole and the soil body → prestressed anchor cable 400 is constructed → drilling and grouting are performed → drill rod is pulled out → casing 100 is pulled out → expansion water stop 402 is wound and blocked at the grouting hole → waist beam is constructed → tensioning and locking are performed.
[0037] (1) The drilling machine is in place and the hole is opened: the drilling machine is placed in place according to the hole position of the anchor cable 400, the drilling machine is leveled with wooden frames or steel plates, and the drilling process is ensured to be stable without large shaking to affect the hole quality. For the silt site, the drilling machine should be replaced or laid with steel plates to ensure that the drilling machine does not shift during the drilling process. After the drilling machine is stable, the hole is calibrated.
[0038] (2) The casing 100 is inserted: the angle of the drilling machine is adjusted according to the design drawing with a compass instrument, and the angle deviation is controlled within ±1°. Then the first drill rod is installed, and then the first casing 100 with a sleeve is installed. Then the casing 100 with a sleeve and the drill bit are aligned with the anchor cable 400 hole position to be constructed and drilled. Then a 6-meter-long casing 100 is installed, and the casing 100 is ensured to protrude out of the hole by 2 meters.
[0039] (3) The gap between the hole and the soil body is filled with soil cloth + expansion water stop 402: the gap between the hole and the casing 100 is blocked with soil cloth + expansion water stop 402.
[0040] (4) Prestressed anchor cable 400 construction: remove the surface of the φ15.2 steel strand oil and rust film, the steel strand according to certain rules straight arrangement, cable anchorage segment along the rod body axis direction every 1.5m set a line ring, grouting pipe should be firmly tied with the rod and cut with abrasive cutting machine, anchor cable 400 according to the design length on the ground and ensure that the anchor device outside the reserved anchor cable 400 length is not less than 1 meter. The free section is wrapped with plastic pipe, and the plastic pipe port at the intersection of the anchoring section is sealed with waterproof tape. The length of the free section is specified in the design drawing. According to the design drawing, the steel strand (diameter determined according to the design drawing) is connected with the anchor disc 401 by spot welding, and an anchor piece is made according to the design drawing, and then it is sleeved on the rotary drill bit.
[0041] (5) Drilling and grouting: high-speed high-power mixing drum is used to mix cement slurry, 42.5R ordinary portland cement is used according to the design requirements, high-pressure jet grouting cement uses pure cement slurry with strength grade PO42.5, water-cement ratio is 0.5-0.55, cement dosage is not less than 400kg / m, and appropriate amount of early strength agent (0.05% of cement weight) and micro-expansion agent (0.05% of cement weight) can be added, or determined according to the test. When the anchor cable 400 is constructed in the water level is more abundant, thickening agent or non-diffusion agent (0.15%-0.5% of cement weight) should be added to reduce the loss of cement slurry affected by tidal water level.
[0042] The prepared anchor piece is sleeved on the hard alloy high-pressure rotary drill bit (nozzle), the drill pipe and the grouting pump are connected, and the design required grouting pump pressure and speed are adjusted. The high-pressure jet pressure of reaming should be 20-25Mpa, and the nozzle moving speed should be 10-20㎜ / min. Start the drilling machine to drill, the high-pressure clean water of the high-pressure rotary drill bit (nozzle) is sprayed outward from the bottom drill bit and the side nozzle under the pressure of the high-pressure pump, and the soil or sand layer around is cut at the same time during the spraying process; the high-pressure rotary drill bit and the side nozzle are gradually pushed forward under the power, until the depth of the anchor rod drill hole is greater than the design length of the anchor rod by 500㎜, and the drilling construction is stopped.
[0043] (6) Pull out the drill pipe: after the anchor cable 400 reaches the design depth, adjust the pressure and speed of the grouting pump again, the grouting pressure is 20-25Mpa, and the nozzle moving speed is 10-20㎜ / min. Start the drilling machine again to pull out the drill pipe, and carry out secondary rotary grouting while pulling out the drill pipe, the grouting pressure and the lifting speed are the same as the rotating speed.
[0044] (7) Pull out the steel casing 100: after the drill pipe is pulled out, clean each drill pipe and grouting nozzle. Then connect the drill power head to the casing 100, start the motor to slowly and uniformly pull out the casing 100 outward, pay attention not to pull out the anchor cable 400 when pulling out the casing 100, and slowly pull back and forth when the anchor cable 400 is pulled out.
[0045] (8)Hole grouting expansion sealing band winding plugging: after the sleeve 100 is pulled out, the expansion sealing band is immediately uniformly wound on the anchor cable 400 to close the hole, and an extra layer is provided to avoid water and soil loss and ensure the stability of the sand layer.
[0046] (9)Waist beam construction: after the construction of the same row of anchor rods is completed, the design drawing requirements are measured and laid out, the cushion is poured, the reinforcement is tied, the 100mm diameter plastic pipe is pre-buried, the formwork is installed, the reinforcement formwork is accepted, the concrete is poured, and the maintenance is constructed.
[0047] (10)Tensioning and locking: after the anchor rod consolidation body strength reaches 80% of the design strength, the anchor plate and anchor are installed and ensured to be perpendicular to the anchor rod axis. The jack is used for anchor rod tensioning in two stages, and the grading load is 1 / 2 of the prestress value. Each stage is held for 5 minutes and the anchor rod displacement is measured. After tensioning to the design load and holding for 10 minutes under the load and measuring the anchor rod displacement, the anchor rod is finally automatically locked by the anchor rod anchor. After the anchor rod tensioning is completed and the detection is qualified, the excess part of the exposed anchor rod is cut off, and 8-12cm should be left to prevent sliding.
[0048] The technical scheme of the utility model adopts a sleeve 100 of a certain length to increase the height of the flowing sand upwelling. The inclination angle and height effectively utilize the self-weight of the flowing sand to reduce the flowing sand outflow. The geotextile + expansion sealing band 402 is used to seal the gap between the steel sleeve and the hole to prevent the flowing sand from flowing out, and the anti-flowing effect is good and the construction is convenient. In addition, the sleeve 100 is pulled out after anchor rod grouting construction, at this time, the cement mortar has a certain flowability before initial setting, so it may be affected by the tide and flow out. Therefore, the expansion sealing band 402 is immediately arranged after the sleeve 100 is pulled out to prevent the cement mortar from overflowing. The construction is convenient, the anti-flowing effect is good, and the construction is convenient.
[0049] In the description of the present specification, the description of the terms "example", "embodiment" or "some embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0050] Of course, the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make equivalent modifications or replacements without departing from the spirit of the present application. These equivalent modifications or replacements are all included in the scope defined by the claims of the present application.
Claims
1. A construction structure for foundation pit support anchor bolts, characterized in that, The system includes a casing and support piles distributed along the perimeter of the foundation pit. The support piles are provided with anchor holes extending from the inside to the outside of the foundation pit. The anchor holes are inclined, with one end of the anchor hole on the inside of the foundation pit being higher than the other end on the outside of the foundation pit. The casing is inserted into the anchor hole, with one end of the casing extending upwards into the inside of the foundation pit and the other end extending downwards into the soil outside the foundation pit. A water-stopping structure is provided between the casing and the wall of the anchor hole.
2. The foundation pit support anchor construction structure according to claim 1, characterized in that, The water-stopping structure includes geotextile and expandable waterstop strip.
3. The foundation pit support anchor construction structure according to claim 1, characterized in that, It also includes anchor cables, which are inserted through the casing and are longer than the casing and extend into the soil outside the pit.
4. The foundation pit support anchor construction structure according to claim 3, characterized in that, An anchor plate is provided at one end of the anchor cable that extends into the soil outside the foundation pit.
5. The foundation pit support anchor construction structure according to claim 3, characterized in that, The anchor cable is provided in multiple ways, and the multiple anchor cables extend along the length direction and are arranged in a straight line.
6. The foundation pit support anchor construction structure according to claim 3, characterized in that, An expansion seal is provided at one end of the anchor cable located inside the foundation pit.
7. The foundation pit support anchor construction structure according to claim 1, characterized in that, The length of the casing extending into the inside of the pit shall not be less than 2 meters.
8. The foundation pit support anchor construction structure according to claim 1, characterized in that, The sleeve is made of metal round tube.