阅读说明：本技术 一种利用锚杆固定沉箱的施工结构及其施工方法 (Construction structure for fixing caisson by using anchor rod and construction method thereof ) 是由 张雪峰 张静涛 高振轩 百世健 李佳兴 方舟 霍俊灼 胡斯 尹双越 杨晓东 于 2021-08-24 设计创作，主要内容包括：本发明公开一种利用锚杆固定沉箱的施工结构及其施工方法,施工结构包括：坑体、抗浮锚杆和沉箱。抗浮锚杆固定在所述坑体底部土层内。沉箱安装在所述坑体内,且所述沉箱和所述抗浮锚杆相连接,所述抗浮锚杆限定所述沉箱的位置。本申请首先施工抗浮锚杆,再进行土方开挖、沉箱安装,待沉箱安装到位后与抗浮锚杆焊接连接并对抗浮锚杆进行预应力张拉以起到抗浮作用。本申请通过抗浮锚杆提供的抗拔力有效的抵抗了沉箱安装后因周围地下水位上涨而产生的浮力,为后续的基础施工提供保障。该锚杆固定沉箱的施工结构工艺工序合理,安全可靠,施工方便,可大幅减少基坑降排水工程量,节约了成本。(The invention discloses a construction structure for fixing a caisson by using an anchor rod and a construction method thereof, wherein the construction structure comprises the following steps: the anti-floating anchor rod comprises a pit body, an anti-floating anchor rod and a caisson. The anti-floating anchor rod is fixed in the soil layer at the bottom of the pit body. The caisson is installed in the pit body, the caisson is connected with the anti-floating anchor rods, and the anti-floating anchor rods limit the position of the caisson. This application is at first constructed anti-floating anchor, carries out earthwork excavation, caisson installation again, treats that the caisson installation targets in place the back and carries out the prestressing force stretch-draw with anti-floating anchor welded connection and anti-floating anchor in order to play anti floating effect. This application is through the effectual buoyancy that produces because of ground water level rises around after the caisson installation of having resisted the anti-floating force that the anti-floating anchor rod provided, provides the guarantee for subsequent basic construction. The construction structure of the anchor rod fixing caisson has the advantages of reasonable process, safety, reliability and convenience in construction, and can greatly reduce the amount of foundation pit lowering and draining engineering and save the cost.)

1. The utility model provides an utilize construction structures of fixed caisson of stock which characterized in that includes:

a pit body;

the anti-floating anchor rod is fixed in the soil layer at the bottom of the pit body;

the caisson is installed in the pit body and is connected with the anti-floating anchor rod, and the anti-floating anchor rod limits the position of the caisson.

2. The construction structure for fixing the caisson using the anchor rods as set forth in claim 1, comprising a plurality of anti-floating anchor rods, each of which is connected to a different position of the caisson, respectively.

3. The construction structure for fixing the caisson by using the anchor rods as claimed in claim 1, wherein the caisson includes a bottom wall and four inclined walls connected to the bottom wall, and the construction structure is provided with a plurality of anti-floating anchor rods corresponding to each of the inclined walls, and each anti-floating anchor rod is connected to the corresponding inclined wall.

4. The construction structure for fixing the caisson by using the anchor rods as claimed in claim 1, wherein the inclined walls are provided with holes, and the anti-floating anchor rods are provided with steel strands which are arranged through the holes.

5. The construction structure for fixing the caisson by using the anchor rods as claimed in claim 4, wherein a tension mechanism is provided on the inclined wall, the tension mechanism comprises a bracket and an anchor head connected to the bracket, and the steel strand is connected to the anchor head.

6. The construction structure for fixing the caisson by using the anchor rod as claimed in claim 5, wherein the support includes an anchor head bearing plate and two supporting members, the two supporting members are spaced apart from each other with a through cavity formed therebetween, the two supporting members each include an upper plate body, a lower plate body and a connecting plate for connecting the upper plate body and the lower plate body, the lower plate body of the supporting member and the caisson are welded and fixed, the anchor head bearing plate is connected to the two upper plate bodies of the supporting members, and the steel strand passes through the through cavity and the anchor head bearing plate and is fixedly connected to the anchor head.

7. A construction method of a construction structure according to any one of claims 1 to 6, comprising:

step S1, drilling holes on undisturbed soil and installing anti-floating anchor rods;

step S2, excavating a pit body on undisturbed soil, and cleaning an anti-floating anchor rod;

step S3, the steel strand on the anti-floating anchor rod penetrates through a caisson, and the caisson is installed in the pit body;

step S4, filling materials between the pit body and the caisson;

and step S5, tensioning the steel strand and locking the anti-floating anchor rod.

8. The construction method according to claim 7, wherein step S2 includes: the anti-floating anchor rod position is marked, the anti-floating anchor rod is prevented from being broken by downwards excavating from two sides of the anti-floating anchor rod position, and after the anti-floating anchor rod is excavated, the anti-floating anchor rod is cleaned and is fixed, tensioned and protected by iron wires to prevent falling.

9. The construction method according to claim 7, wherein the step S4 includes filling a bottom cement grout in a gap between the bottom wall of the caisson and the pit body, pouring a side wall backfill graded sand grout between the bottom wall surface of the inclined wall and the pit body, and filling concrete between the top wall surface of the inclined wall and the foundation pit.

10. The construction method according to claim 7, further comprising, after step S4, pumping excess water in the caisson after the strength of the grouting material reaches 75% of the design strength, wherein the weight in the caisson is ensured to be greater than the buoyancy of water outside the caisson during the pumping, so as to prevent the caisson from floating up and dislocating.

Technical Field

The invention relates to the technical field of building construction, in particular to a construction structure for fixing a caisson by using an anchor rod and a construction method thereof.

Background

The deep foundation pit precipitation prevention construction is an important component in deep foundation pit engineering construction, and a caisson water-resisting method is generally adopted in the prior art to reduce the precipitation displacement of underground water, so that the cost can be effectively reduced. However, the conventional caisson construction has the problem that the caisson which is installed in place floats upwards due to the fact that the underground water level continuously rises. If the treatment is improper, the caisson may be locally bulged by the pressure of underground water, bulged and deformed, the caisson body is damaged to cause leakage, the caisson integrally floats upwards and the like.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention provides a construction structure for fixing a caisson by using an anchor rod and a construction method thereof.

In order to solve the above problems, the present disclosure adopts the following technical solutions:

a first object of the present application is to provide a construction structure using an anchor rod to fix a caisson, including:

a pit body;

the anti-floating anchor rod is fixed in the soil layer at the bottom of the pit body;

the caisson is installed in the pit body and is connected with the anti-floating anchor rod, and the anti-floating anchor rod limits the position of the caisson.

Optionally, the construction structure for fixing the caisson by using the anchor rods comprises a plurality of anti-floating anchor rods, and each anti-floating anchor rod is respectively connected to different positions of the caisson.

Optionally, the caisson comprises a bottom wall and four inclined walls connected with the bottom wall, the construction structure is provided with a plurality of anti-floating anchor rods corresponding to each inclined wall, and each anti-floating anchor rod is connected to the corresponding inclined wall.

Optionally, a hole is formed in the inclined wall, the anti-floating anchor rod is provided with a steel strand, and the steel strand penetrates through the hole.

Optionally, set up tensioning mechanism on the cliff side, tensioning mechanism includes the support and connects anchor head on the support, the steel strand wires with the anchor head is connected.

Optionally, the support includes anchor head bearing plate and two support piece, two the support piece interval sets up, is formed with between, two through the chamber support piece all includes upper plate body, lower plate body and connects the connecting plate of upper plate body and lower plate body, support piece's lower plate body with caisson welded fastening, anchor head bearing plate connects two on support piece's the upper plate body, steel strand wires pass through the chamber with anchor head bearing plate with the anchor head is connected fixedly.

A second object of the present application is to provide a construction method of the above construction structure, including:

step S1, drilling holes on undisturbed soil and installing anti-floating anchor rods;

step S2, excavating a pit body on undisturbed soil, and cleaning an anti-floating anchor rod;

step S3, the steel strand on the anti-floating anchor rod penetrates through a caisson, and the caisson is installed in the pit body;

step S4, filling materials between the pit body and the caisson;

and step S5, tensioning the steel strand and locking the anti-floating anchor rod.

Optionally, step S2 includes: the anti-floating anchor rod position is marked, the anti-floating anchor rod is prevented from being broken by downwards excavating from two sides of the anti-floating anchor rod position, and after the anti-floating anchor rod is excavated, the anti-floating anchor rod is cleaned and is fixed, tensioned and protected by iron wires to prevent falling.

Optionally, step S4 includes filling a bottom cement grout into the gap between the bottom wall of the caisson and the pit body, pouring a sidewall backfill graded sand grout between the bottom wall of the inclined wall and the pit body, and filling concrete between the top wall of the inclined wall and the foundation pit.

Optionally, after step S4, the method further includes pumping excess water in the caisson after the strength of the grouting body reaches 75% of the design strength, and ensuring that the counter weight in the caisson is greater than the buoyancy of water outside the caisson during the pumping process, thereby preventing the caisson from floating up and dislocating.

By adopting the technical scheme, the invention has the following beneficial effects:

this application is through the effectual buoyancy that produces because of ground water level rises around after the caisson installation of having resisted the anti-floating force that the anti-floating anchor rod provided, provides the guarantee for subsequent basic construction. The construction structure of the anchor rod fixing caisson has the advantages of reasonable process, safety, reliability and convenient construction, can greatly reduce the amount of foundation pit water-lowering and water-draining engineering, and is favorable for saving cost.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention to its proper form. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a top view of a caisson of a construction Structure provided in accordance with the invention;

FIG. 2 is a bottom view of a caisson of a construction Structure provided in accordance with the invention;

FIG. 3 is a schematic diagram of drilling an anti-floating anchor rod in undisturbed soil;

FIG. 4 is a schematic view of a pit body being excavated in undisturbed soil;

FIG. 5 is a schematic illustration of loading a caisson into a pit;

FIG. 6 is a schematic view of the filling of material between the pit body and the caisson;

FIG. 7 is a schematic view of the construction of the tensioning mechanism;

fig. 8 is a schematic view of a construction structure provided by the present invention.

In the figure, 1, a caisson; 11. a bottom wall; 12. an inclined wall; 121. a hole; 122. a triangular bracket; 123. i-shaped steel; 124. channel steel; 125. steel plate strips; 2. an anti-floating anchor rod; 21. steel strand wires; 3. undisturbed soil; 31. a pit body; 4. a tensioning mechanism; 41. a support member 42, an anchor head bearing plate; 43. an anchor head; 5. a communicating vessel; 6. bottom cement grout body; 7. backfilling graded sandstone grouting bodies on the side walls; 8. concrete; 9. a raft foundation.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or assembly must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

Referring to fig. 1 to 8, in an embodiment of the present application, there is provided a construction structure for fixing a caisson 1 using an anchor, including: pot 31, anti-floating anchor rod 2 and caisson 1. The anti-floating anchor rod 2 is fixed in the soil layer at the bottom of the pit body 31. The caisson 1 is installed in the pit body 31, and the caisson 1 and the anti-floating anchor 2 are connected, and the anti-floating anchor 2 defines the position of the caisson 1. This application is at first constructed anti-floating anchor 2, carries out earthwork excavation, caisson 1 installation again, treats that caisson 1 installs the back of targetting in place and carries out the prestressing force stretch-draw with anti-floating anchor 2 welded connection and to anti-floating anchor 2 and play anti-floating effect. This application is through the effectual buoyancy that produces because of ground water level rises around 1 installation backs of resisting of anti-floating anchor rod 2 provides, provides the guarantee for subsequent foundation construction. The construction structure of the anchor rod fixing caisson 1 is reasonable in process, safe, reliable and convenient to construct, and can greatly reduce the amount of foundation pit water-lowering and water-draining engineering, thereby being beneficial to saving the cost.

In a possible embodiment, the construction structure for fixing the caisson 1 by using the anchor rod includes a plurality of anti-floating anchor rods 2, and the anti-floating anchor rods 2 are respectively connected to different positions of the caisson 1. The caisson 1 comprises a bottom wall 11 and four inclined walls 12 connected with the bottom wall 11, a plurality of anti-floating anchor rods 2 are arranged on the construction structure corresponding to each inclined wall 12, and each anti-floating anchor rod 2 is connected to the corresponding inclined wall 12. Through the design of a plurality of anti-floating anchor rods 2, the caisson 1 can be effectively tensioned and limited, and the caisson 1 is prevented from inclining.

In a possible embodiment, a hole 121 is formed in the inclined wall 12, and the anti-floating anchor rod 2 has a steel strand 21, and the steel strand 21 is disposed through the hole 121. By passing the steel strands 21 through the holes 121 in advance, later installation and tensioning are facilitated.

Optionally, a tensioning mechanism 4 is arranged on the inclined wall 12, the tensioning mechanism 4 includes a support and an anchor head 43 connected to the support, and the steel strand 21 is connected to the anchor head 43.

Referring to fig. 7, the support includes an anchor head bearing plate 42 and two supporting members 41, two supporting members 41 are arranged at intervals, a through cavity is formed between the supporting members 41, each supporting member 41 includes an upper plate body, a lower plate body and a connecting plate for connecting the upper plate body and the lower plate body, the lower plate body of the supporting member 41 is welded and fixed to the caisson 1, the anchor head bearing plate 42 is connected to the upper plate body of the supporting member 41, and the steel strand 21 passes through the through cavity and the anchor head bearing plate 42 and is connected and fixed to the anchor head 43.

Further, the construction structure for fixing the caisson 1 by using the anchor rod further comprises a communicating vessel 5, wherein the communicating vessel 5 is connected to the caisson 1, and a communicating port for communicating the communicating vessel 5 is formed in the caisson 1. The communicating vessel 5 can be the tubulose, and the design of communicating vessel 5 is convenient for caisson 1 sinks to the design elevation, and communicating vessel 5 still can carry out emergent pump drainage precipitation, reduces water pressure, prevents effectively that later stage water level from rising to cause that water pressure is too big to lead to caisson 1 intensity to lead to warping too big, and communicating vessel 5 still can be used to the reinforcement of follow-up caisson 1 bottom slip casting simultaneously.

Wherein, the caisson 1 includes a bottom wall 11 and an inclined wall 12 connected to the peripheral side of the bottom wall 11, and the communicating vessel 5 is connected to the bottom wall 11. The 11 low positions of diapire for the linker 5 is more close ponding one side, makes things convenient for the pump drainage ponding.

In a possible embodiment, the caisson construction Structure comprises a plurality of connectors 5, each of said connectors 5 being placed in a different position of caisson 1. The communicating vessels 5 are large in number, so that the caisson 1 can sink more conveniently, and quick pumping drainage and precipitation can be facilitated. Preferably, four communication vessels 5 may be provided on the bottom wall 11, the four communication vessels 5 being provided on the bottom wall 11 near the four corners.

In a possible embodiment, the construction structure further comprises a grouting pipe, the grouting pipe extends along the outer wall of the caisson 1, and a plurality of fixing structures for fixing the grouting pipe are arranged on the outer wall of the caisson 1.

The fixed structure comprises two I-shaped steels, the two I-shaped steels are welded on the outer wall of the caisson 1, and the positions of the concave sides of the two I-shaped steels are oppositely arranged to form a grouting pipe clamping space.

Wherein, the slip casting pipe can include lateral part slip casting pipe and bottom slip casting pipe, lateral part slip casting union coupling in on the inclined wall 12, bottom slip casting union coupling in on the diapire 11, just bottom slip casting pipe with the linker 5 is connected. By connecting the bottom grouting pipe with the communicating vessel 5, grouting to a position below the bottom wall 11 is facilitated.

In the embodiment of the application, the caisson 1 needs to be strictly processed according to the design size, the panel material of the caisson 1 adopts a 6mm steel plate, the angle between the inclined wall 12 and the bottom wall 11 of the caisson 1 is 45 degrees, and the steel plate splicing of the water-resisting caisson 1 adopts a double-sided full-welding mode to ensure that the caisson 1 is sealed and is impermeable. After the surface layer of the water-resisting caisson 1 is spliced, reinforcing the inner surface and the outer surface of the water-resisting caisson 1 by using 8# channel steel 124, 14# I-steel 123 and a triangular support 123, reinforcing the weak and large stressed parts by using a steel plate strip 125, and ensuring the integrity of the steel plate strip 125 connected with the channel steel and the I-steel at the corner.

Example two

The second embodiment of the present application provides a construction method for fixing a construction structure of a caisson 1 by using an anchor rod in the first embodiment, which specifically includes the following steps:

step S1, referring to fig. 3, drilling and installing the anti-floating anchor rod 2 on the undisturbed soil 3;

the top elevation of original state soil 3 is raft foundation 9 big face bottom elevation, anti-floating anchor 2 is in advance the construction of drilling slip casting is carried out to original state soil 3 upper surface. Preferably, two anti-floating anchors 2 may be connected to each of the inclined walls 12 around the installed water-stop caisson 1. The anti-floating anchor rod 2 can adopt steel strands 21, exemplarily, a positioner can be welded every 2.0m, the total length of the anchor rod is 15m, the length of the free end is 5m, the length of the anchoring section is 10m, and the locking value is 300 KN. The anti-floating anchor rod 2 is used for measuring the anchor rod hole forming depth 18m from a large surface.

Step S2, referring to fig. 4, excavating a pit 31 in the undisturbed soil 3, and cleaning the anti-floating anchor rod 2;

and excavating the undisturbed soil 3 after the drilling and grouting construction of the anti-floating anchor rod 22 is completed. The position of the prestressed anti-floating anchor rod 2 is marked before excavation, and the prestressed anti-floating anchor rod 2 is excavated downwards from two sides of the position of the prestressed anti-floating anchor rod 2 during excavation so as to prevent the prestressed anti-floating anchor rod 2 from being excavated. After excavating out the prestressed anti-floating anchor rod 2, the prestressed anti-floating anchor rod 2 is manually cleaned out and is fixed by an iron wire to be tensioned and protected to prevent falling.

Step S3, the steel strand 21 on the anti-floating anchor rod 2 penetrates through the caisson 1, and the caisson 1 is installed in the pit body;

after partial anti-floating anchor rods 2 are cleaned, holes 121 with phi of 50mm are cut in the inclined wall 12 of the processed water-proof caisson 1 according to the position of the anti-floating anchor rods 2 under the measured stress, so that steel strands 21 of the anti-floating anchor rods 2 can smoothly penetrate through the holes, and steel pipe connectors 5 with phi of 300 x 8 are welded in the holes cut in the bottom of the caisson 1, so that the caisson 1 sinks and the later stage underground water level rises to pump water for emergency.

And after the undisturbed soil 3 is excavated to the bottom elevation of the caisson 1, hoisting the caisson 1 in place by adopting a crawler crane. The caisson 1 sinks by using a mode that the communicating vessel 5 releases partial water pressure and increases the balance weight in the installation process, and the position of the caisson 1 is continuously adjusted in the process of sinking the caisson 1.

Step S4, referring to fig. 6, filling a material between the pit body and the caisson 1;

step S4 includes filling a bottom cement grout 6 into a gap between the bottom wall 11 of the caisson 1 and the pit body, pouring a sidewall backfill graded sand grout 7 between the bottom wall surface of the inclined wall 12 and the pit body, and filling C20 concrete 8 between the top wall surface of the inclined wall 12 and the foundation pit. After the backfill of the position of the inclined wall 12 is finished, a bottom grouting pipe is preset at the bottom of the communicating vessel 5 to perform grouting reinforcement on the bottom area of the water-resisting caisson 1, wherein a cement grouting body can adopt P.042.5, and the grouting proportion is 0.5-0.55.

After step S4, after the strength of the grouting material reaches 75% of the design strength, pumping excess water inside the caisson 1, and ensuring that the internal balance weight of the caisson 1 is greater than the external water buoyancy of the caisson 1 during the pumping process, thereby preventing the caisson 1 from floating up and dislocating.

And step S5, tensioning the steel strand 21 and locking the anti-floating anchor rod 2.

After the steel strand 21 is tensioned and locked, cutting the redundant steel strand 21 on the anchor head and closing the redundant steel strand 21 by using a prefabricated box cap.

Step S6, backfilling the communicating vessels 5 in the caisson 1 with concrete, and sealing the communicating vessels 5;

and after bottom grouting and side wall grouting are completed and the strength meets the requirement, C20 concrete can be adopted to backfill the communicating vessel 5 in the caisson 1, and the communicating vessel 5 is sealed. And after the construction steps are completed, the foundation concrete construction can be carried out.

Step S7, referring to fig. 8, performing raft structure construction on the top of caisson 1 to form raft foundation 9.

In summary, the construction scheme of the invention is that the anti-floating anchor rod 2 is firstly constructed before the earth excavation, then the earth excavation and the caisson 1 installation are carried out, and after the caisson 1 is installed in place, the caisson is welded with the anti-floating anchor rod 2 and is prestressed and tensioned to the anti-floating anchor rod 2, so as to play the anti-floating role. And in the processing process of the caisson 1, holes are formed after actual positioning on site, so that the accuracy of the connection position of the anti-floating anchor rod 2 and the caisson 1 is ensured. The uplift resistance provided by the anti-floating anchor rod 2 effectively resists the buoyancy generated by the rising of the underground water level around the caisson 1 after the caisson is installed, and provides guarantee for subsequent basic construction.

In the embodiment of the invention, 4 connectors 5 for machining phi 300 x 8mm steel pipes are arranged in the caisson 1, so that the caisson 1 can sink to the designed elevation conveniently. And in the later stage, emergency pumping drainage and precipitation can be performed by using the communicating vessel 5, so that the water pressure is reduced, and the phenomenon that the strength of the caisson 1 is too large due to the fact that the water pressure is too large and the water level rises in the later stage is effectively prevented from being too large. Finally, the communicating vessel 5 can also be used for the reinforcement of the subsequent grouting at the bottom of the caisson 1. Utilize linker 5 release partial water pressure and combine to apply the mode of counter weight to sink in caisson 1 installation, constantly adjust caisson 1 position at caisson 1's in-process, after guaranteeing that caisson 1 descends to preset position and design elevation smoothly, guarantee through the mode of water injection and applying the counter weight that caisson 1 does not take place the skew dislocation at the reinforced in-process of backfill slip casting, provide the guarantee for subsequent raft foundation 9 construction. The construction method has reasonable procedures, is safe and reliable, is convenient to construct, can greatly reduce the amount of drainage engineering of the foundation pit, and is favorable for saving the cost.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.