Construction system and method for reserving anti-floating anchor hole forming position in foundation bed

Abstract

The invention discloses a construction system and method for reserving an anti-floating anchor rod hole-forming position in a foundation bed, and belongs to the technical field of foundation engineering construction.The construction system comprises a plurality of positioning steel bars fixed in a soil body, and the positioning steel bars are located at the circle center of an anchor hole; positioning pipes are arranged on the outer sides of the positioning steel bars, and circle center vertical projections of the positioning pipes coincide with the positioning steel bars; a cushion layer is poured outside the positioning pipe; after the cushion layer is initially set, the positioning pipe is detached to form a positioning hole, an anchor hole is drilled in the positioning hole, and the circle center of the anchor hole is consistent with that of the positioning hole. Two anchor hole positioning measures are adopted, a plurality of positioning holes are accurately reserved in the cushion layer, and anchor hole construction is performed in the positioning holes, so that the technical problem that the cushion layer can be damaged when holes are drilled in the cushion layer is solved, and the technical problems that positioning paint spraying is performed on the cushion layer, a drilling machine moves back and forth, and mud emerging after drilling covers the positioning paint are solved; therefore, the problems that positioning is difficult and anchor holes deviate in the traditional technology are solved, the anchor hole construction period is greatly shortened, positioning is accurate, and efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation engineering construction, and in particular relates to a construction system and method for reserving anti-floating anchor hole forming positions in a foundation cushion layer. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Anti-floating of underground structures has always been an important issue faced in foundation engineering. The focus is on how to resist the buoyancy of groundwater on structures to ensure the overall stability and safety of buildings. The problem of anti-floating of underground structures is widely present in projects such as underground garages, subway stations, sunken squares, basements of super high-rise buildings, and offshore dock platforms. Especially in coastal areas and areas with high groundwater levels, the problem of anti-floating of underground projects is more severe.

[0004] As an important technical means to resist the buoyancy of groundwater and ensure the safety of structures, anti-floating anchor rods can effectively solve the problem of anti-floating of underground projects. At the same time, the setting of anti-floating anchor rods can limit the deformation of the overall structure and improve the stability of the building. Compared with the drainage method and the weighting method, anti-floating anchor rods have the advantages of strong stratum adaptability, stress dispersion, simple construction and low cost. Therefore, anti-floating anchor rods are widely used in anti-floating projects of underground structures.

[0005] At present, for sites with geological conditions of moderately weathered rock strata, the installation of anti-floating anchor rods has the advantages of high pull-out bearing capacity, convenient construction, economy and environmental protection, and small space occupation compared with other anti-floating technical measures. Therefore, the installation of anti-floating anchor rods in areas with geological conditions of moderately weathered rock strata is an important means of anti-floating in underground engineering.

[0006] However, the construction of anti-floating anchors in areas with moderately weathered rock formations still faces the following problems that are difficult to resolve: on the one hand, positioning is difficult. The current "Technical Standard for Anti-Floating of Construction Engineering" (JGJ476-2019) stipulates that the allowable deviation of the anchor hole position of the anti-floating anchor shall not exceed ±100mm, and the inclination of the anchor hole shall not exceed 2% of the length of the anchor hole. In the positioning of the anchor hole, the commonly used method is to set the steel bar head at the positioning position or to spray paint on the cushion layer at the positioning position, but the effects of these two positioning methods are poor; during the construction of the anchor hole, the reciprocating movement of the drilling rig and the mud that emerges after drilling will cover the positioning hole, which brings great difficulties to the positioning of the anti-floating anchor and can easily cause the position of the anti-floating anchor to shift. On the other hand, in the above positioning method, the anchor holes need to be constructed starting from the set cushion layer. It is necessary to drill holes in the concrete cushion layer before constructing the anchor holes. Due to the high strength of the cushion layer concrete, it is difficult for the drill rig to drill, which greatly prolongs the construction period of the anti-floating anchor rod. At the same time, when the drill rig drills holes in the cushion layer, the vibration during the drilling operation will cause the cushion layer to crack and be damaged, resulting in poor adhesion between the waterproof layer and the cushion layer during the subsequent waterproof construction, thereby increasing the hidden danger of water seepage in the underground structure, reducing the waterproof performance of the underground structure, affecting the normal use of the structure, and increasing the cost of subsequent operation and maintenance. Summary of the invention

[0007] In view of the above problems, the present invention provides a construction system and method for reserving drilling positions for anti-floating anchor rods in a foundation cushion layer. By setting two anchor hole positioning measures, a plurality of positioning holes are accurately reserved in the cushion layer, and anchor hole construction is carried out in the positioning holes, thereby solving the technical problem that drilling holes in the cushion layer will damage the cushion layer in the traditional process. At the same time, it also solves the technical problem that the positioning paint is covered by the positioning paint during positioning spraying on the cushion layer, the back and forth movement of the drilling rig, and the mud emerging after drilling, thereby solving the positioning difficulty and the anti-floating anchor rod offset problem existing in the traditional process, can greatly shorten the construction period of the anchor hole, and has accurate positioning and high efficiency.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, a construction system for reserving a hole position for an anti-floating anchor rod in a foundation cushion layer is provided, comprising a plurality of positioning steel bars fixed in the soil, each positioning steel bar being located at the center of each anchor hole;

[0010] Positioning tubes are set on the outside of the positioning steel bars, and the vertical projection of the center of the positioning tubes coincides with the positioning steel bars; a cushion layer is poured on the outside of the positioning tubes;

[0011] After the cushion layer initially sets, the positioning tube is removed to form a positioning hole. An anchor hole is drilled in the positioning hole by a hydraulic down-the-hole drill. The center of the anchor hole is consistent with that of the positioning hole. The anchor hole is used to place the anchor rod body equipped with a split anti-floating anchor locator.

[0012] Preferably, the positioning tube comprises a steel cylinder, which is a hollow cylinder, with multiple fixed steel bars uniformly welded at the bottom of the steel cylinder, and multiple positioning steel wires uniformly fixedly arranged at the top; the length of the positioning steel wires is equal to the diameter of the steel cylinder, and the intersection point between the positioning steel wires is the same as the center of the steel cylinder;

[0013] A steel pad is placed on top of the positioning tube and then hammered into the steel pad to drive the fixing reinforcement into the soil.

[0014] Preferably, the height of the steel cylinder is at least 100 mm greater than the thickness of the cushion layer, and the height of the steel cylinder is greater than the length of the positioning steel bar.

[0015] Preferably, the outer wall diameter of the positioning tube is larger than the diameter of the anchor hole, and the thickness of the steel tube is larger than or equal to the diameter of the fixed steel bar.

[0016] Preferably, threaded segments are arranged on the anchor rod body at set length intervals, a threaded through hole is opened at the center of the split anti-floating anchor rod locator, the inner diameter of the split anti-floating anchor rod locator is the same as the diameter of the anchor rod body, and multiple split anti-floating anchor rod locators are fixed to the multiple threaded segments of the anchor rod body by means of threaded connection; the outer diameter of the split anti-floating anchor rod locator is the same as the diameter of the anchor hole.

[0017] In a second aspect, a construction method for reserving a hole position for an anti-floating anchor rod in a foundation cushion layer is provided, which uses the above-mentioned construction system for reserving a hole position for an anti-floating anchor rod in a foundation cushion layer, and specifically includes:

[0018] S1. Set the positioning steel bars and install the positioning pipes;

[0019] S2, cushion layer pouring construction;

[0020] S3, taking out the positioning steel bars and the positioning tube to form a positioning hole;

[0021] S4, drilling anchor holes in the positioning holes;

[0022] S5. Install the anchor rod body and grouting;

[0023] S6. Construct waterproof layer and protective layer.

[0024] Preferably, in S1, a total station is used to perform positioning according to the designed position of the anchor rod body, and the positioning steel bar is fixed in the soil at each positioning position. The positioning tube is placed on the soil with the positioning steel bar as the center point, and then the intersection of the positioning steel wires is aimed at the axis of the positioning steel bar; then a steel pad is placed horizontally on the top of the positioning tube, and the steel pad is hit with a hammer to make the fixed steel bar completely inserted and fixed in the soil.

[0025] Preferably, in S4, after the cushion layer maintenance is completed, a hydraulic down-the-hole drill is used to drill in the positioning hole, and after the hole is cleaned, an anchor hole is formed; when the hydraulic down-the-hole drill is constructed on the cushion layer, a waste template must be set under its chain wheel as a pad.

[0026] Preferably, in S5, the anchor rod body equipped with the split anti-floating anchor rod positioner is lowered into the anchor hole, and grouting is performed after the anchor rod body is installed, and the grouting adopts the bottom hole reverse pressure grouting method;

[0027] When grouting, the positioning holes should be grouted at the same time to ensure that the top surface of the grouting body is flush with the top surface of the cushion layer.

[0028] Preferably, in S6, after the grouting body is completely solidified, the mud generated when constructing the anchor holes on the cushion layer is cleaned, and then the waterproof layer and the protective layer are constructed; finally, a water-swellable water-stop strip is set and a non-curing waterproof coating is poured to fill and seal the gaps and pores between the anchor rod body and the cushion layer, and between the waterproof layer and the protective layer.

[0029] Compared with the prior art, the present invention has the following advantages and positive effects:

[0030] 1. The present invention determines the center of the anchor hole by arranging positioning steel bars at the positioning position of the anchor rod body; after arranging the positioning tube outside the positioning steel bars, the cushion layer is poured, and then the positioning steel bars and the positioning tube are removed to form a positioning hole, and the anchor hole is drilled in the positioning hole; by arranging two anchor hole positioning measures, a number of positioning holes are accurately reserved in the cushion layer, and the anchor hole construction is carried out in the positioning hole, which solves the technical problem that drilling holes on the cushion layer will damage the cushion layer in the traditional process, and also solves the technical problem that the positioning paint is covered by the back and forth movement of the drilling rig and the mud emerging after drilling in the traditional process during positioning spraying on the cushion layer, thereby solving the positioning difficulty and the deviation problem of the anti-floating anchor rod in the traditional process, and can greatly shorten the construction period of the anchor hole, with accurate positioning and high efficiency.

[0031] 2. The present invention does not need to drill holes on the cushion layer before constructing the anchor holes, which can save concrete, has low requirements on the site environment and workers' technical skills, and reduces construction costs.

[0032] 3. The present invention can prevent the cushion layer from being damaged due to the vibration generated by the drill rig when drilling holes on the cushion layer, and prevent the cushion layer from being damaged, resulting in loose bonding between the waterproof layer and the cushion layer during the subsequent construction of the waterproof layer, thereby reducing the hidden danger of water seepage in the foundation, improving the waterproof performance of the foundation, and the fastening effect is safe and reliable.

[0033] 4. The positioning steel bars and positioning tubes designed in the present invention can be reused according to the cushion construction in different areas, with low material loss and high turnover rate, which is both material-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] Figure 1 is a cross-sectional view of the construction system during maintenance of Example 1 or Example 2 of the present invention;

[0036] Figure 2 is a top view of the construction system of Embodiment 1 or Embodiment 2 of the present invention during maintenance;

[0037] Figure 3 is a front view of the positioning tube of Example 1 or Example 2 of the present invention;

[0038] Figure 4 is a top view of the positioning tube of Example 1 or Example 2 of the present invention;

[0039] Figure 5 is a bottom view of the positioning tube of Example 1 or Example 2 of the present invention;

[0040] Figure 6 is a cross-sectional view of the construction system of Embodiment 1 or Embodiment 2 of the present invention after the positioning pipe is removed;

[0041] Figure 7 is a cross-sectional view of the construction system of Embodiment 1 or Embodiment 2 of the present invention when placing an anchor rod body;

[0042] In the figure:

[0043] 1. Positioning steel bars; 2. Positioning tube; 21. Steel tube; 22. Fixed steel bars; 23. Positioning wire; 24. Removal handle; 3. Soil; 4. Cushion layer; 5. Positioning hole; 6. Anchor hole; 7. Anchor rod body; 8. Split anti-floating anchor rod locator. DETAILED DESCRIPTION

[0044] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0045] The present invention is described in detail below in conjunction with the accompanying drawings.

[0046] Example 1

[0047] This embodiment discloses a construction system for reserving anti-floating anchor hole positions in a foundation cushion layer, such as Figure 1 , Figure 2 , Figure 6 , Figure 7As shown, it includes a plurality of positioning steel bars 1 fixed in the soil 3. Specifically, a total station is used to locate according to the designed position of the anchor rod body 7. The positioning steel bars 1 are fixed in the soil 3 at each positioning position. Each positioning steel bar 1 should be located at the center of each anchor hole 6. A positioning tube 2 is arranged on the outside of the positioning steel bars 1. The vertical projection of the center of the positioning tube 2 coincides with the positioning steel bars 1. A cushion layer 4 is poured on the outside of the positioning tube 2. After the cushion layer 4 is initially set, the positioning tube 2 is removed to form a positioning hole 5. In the positioning hole 5, an anchor hole 6 is drilled by a hydraulic down-the-hole drill. The anchor hole 6 is used to place the anchor rod body 7 with a split anti-floating anchor rod locator 8 installed.

[0048] In this embodiment, the positioning steel bar 1 is used as the first positioning measure for the positioning position of the anchor hole 6, and the center of the anchor hole 6 is marked; the positioning steel bar 1 adopts a smooth round steel bar with a diameter of 10 mm, and the lower end of the positioning steel bar 1 is sharpened so that it can be smoothly inserted vertically into the soil 3; in this embodiment, a circular paint mark is made at a position 50 mm upward from the lower tip of the positioning steel bar 1, and the function of the circular paint mark is mainly to limit the depth of the positioning steel bar 1 inserted into the soil 3; when the positioning steel bar 1 is hit by a hammer to penetrate the soil, when the bottom of the circular paint mark just touches the surface of the soil, the positioning steel bar 1 reaches a fixed depth of 50 mm.

[0049] like Figure 1 As shown, a positioning tube 2 is arranged outside the positioning steel bar 1, and the bottom of the positioning tube 2 is also arranged in the soil 3. Specifically, as Figure 3 , Figure 4 , Figure 5 As shown, the positioning tube 2 includes a steel cylinder 21, which is a hollow cylinder. A plurality of fixed steel bars 22 are evenly welded on the bottom of the steel cylinder 21, and a plurality of positioning steel wires 23 are evenly fixed on the top of the steel cylinder 21. The length of the positioning steel wire 23 is equal to the diameter of the steel cylinder 21, and the intersection of the plurality of positioning steel wires 23 is the center of the bottom surface of the steel cylinder 21. A pair of removal handles 24 are symmetrically welded on both sides of the outer side of the upper part of the steel cylinder 21. The main function of the removal handles 24 is to use a hammer to gently hammer the positioning tube 2 after the cushion layer construction is completed and initially solidified. After the positioning tube 2 is peeled off and loosened from the cushion layer, lift the removal handles 24 with both hands to facilitate the removal of the positioning tube 2. In this embodiment, there are four fixed steel bars 22, all of which are round steel bars with a diameter of 10 mm and a length of 50 mm. The lower ends of the four fixed steel bars 22 are sharpened so that they can penetrate the soil smoothly. The four fixed steel bars 22 are welded to the bottom of the steel cylinder 21 and are distributed at the four vertices of a square. The positioning tube 2 is set outside the positioning steel bar 1 by fully inserting and fixing the four fixed steel bars 22 in the soil 3. It is ensured that the position of the positioning tube 2 will not be offset during the construction of the cushion layer 4. In this embodiment, the length of the fixed steel bar 22 is 50 mm, that is, the fixing depth of the positioning tube 2 is 50 mm.

[0050] In this embodiment, if Figure 2 As shown, two positioning steel wires 23 are provided, and the lengths of both are equal to the diameter of the steel cylinder 21. The two positioning steel wires 23 are perpendicular to each other, and the vertical projection of the intersection of the two positioning steel wires is located at the same point as the center of the bottom surface of the steel cylinder 21. In this embodiment, a steel pad is placed on the top of the positioning tube 2, and the size of the steel pad is larger than the diameter of the steel cylinder 21; the fixed steel bar 22 is hammered into the soil 3 by hammering the steel pad. The padding of the steel pad ensures that the annular ribs of the positioning tube 2 are evenly stressed during the hammering of the positioning tube 2, avoiding direct impact that causes damage such as edge curling on the top of the positioning tube 2, thereby enhancing its reusability.

[0051] Before hammering, the intersection of the two positioning steel wires 23 is made to coincide with the positioning steel bar 1, that is, the center of the bottom surface of the steel tube 21 is aligned with the positioning steel bar 1, and then the fixing steel bar 22 is set in the soil 3 by hammering. That is, the main function of the positioning steel wire 23 is to aim at the top center of the positioning steel bar 1 before hammering the fixed positioning tube 2, so that the central axis of the positioning tube 2 coincides with the central axis of the positioning steel bar 1, that is, coincides with the center of the anchor hole 6.

[0052] In this embodiment,

[0053] The cushion layer 4 is cast with concrete, and its thickness is determined according to the design of the foundation slab of the anti-floating structure; in this embodiment, the cushion layer is cast with C15 concrete, and the cushion layer thickness is 100mm. It should be noted that the height of the steel cylinder 21 is at least 100mm greater than the thickness of the cushion layer 4, to ensure that the mortar will not be mistakenly poured into the steel cylinder 21 during the construction of the cushion layer 4, to ensure that the minimum construction will not be affected when the cushion layer 4 is finished, and the positioning tube 2 can also facilitate the workers to mark the height when the cushion layer is finished. In this embodiment, the height of the steel cylinder 21 is 200mm.

[0054] It should also be noted that before the fixed steel bar 22 is set in the soil 3, the upper end of the positioning steel bar 1 should be at a distance from the positioning wire 23 at the top of the positioning tube 2. The purpose is to prevent the positioning steel bar 1 from being too long when the fixed steel bar 22 is hammered into the soil 3, thereby hindering the process of hammering the positioning tube 2. In this embodiment, the length of the positioning steel bar 1 is 150 mm. After the fixed steel bar 22 is fixed to the soil 3, the intersection of the positioning wire 23 is still located at the upper end of the positioning steel bar 1. This is to prevent the bottom of the steel tube 21 from being hammered into the soil 3 due to excessive hammering, and the positioning wire 23 will be broken by the positioning steel bar 1.

[0055] Since the anchor hole 6 is drilled in the positioning hole 5, and the positioning hole 5 is formed after the cushion layer 4 is constructed and the positioning tube 2 is removed, the diameter of the positioning tube 2 should be larger than the diameter of the anchor hole 6, that is, the diameter of the positioning hole 5 is larger than the diameter of the anchor hole 6 to prevent damage to the cushion layer 4 when drilling the anchor hole 6; in this embodiment, the diameter of the anchor hole 6 is 110 mm, and the diameter of the outer wall of the positioning tube 2 is 150 mm; the steel cylinder 21 is made of a steel plate with a thickness of 10 mm and is used for welding and fixing steel bars and positioning wires.

[0056] like Figure 6 As shown, after the cushion layer 4 initially sets, the positioning steel bar 1 and the positioning tube 2 are taken out to form a positioning hole 5, which is the second positioning measure for the position of the anchor hole 6. The diameter and height of the formed positioning hole 5 are respectively equal to the diameter of the outer wall of the positioning tube 2 and the thickness of the cushion layer 4.

[0057] In the positioning hole 5, the anchor hole 6 is drilled by a hydraulic down-the-hole drill. It is understandable that the center of the anchor hole 6 coincides with the center of the positioning hole 5. Compared with ordinary drilling rigs, hydraulic down-the-hole drills have the advantages of higher efficiency, stronger adaptability, simple operation, and high safety. It should be noted that when the hydraulic down-the-hole drill is constructed on the cushion layer 4, a waste template must be set under the chain wheel as a pad to ensure that the cushion layer 4 will not be damaged.

[0058] like Figure 7 As shown, after the anchor hole 6 is drilled, the anchor rod body 7 with the split anti-floating anchor rod locator 8 installed is placed in the anchor hole; the model and length of the anchor rod body 7 are determined according to the actual engineering design requirements. In this embodiment, the model of the anchor rod body 7 is HRB500, the diameter is 28mm, and the length is 10m. The anchor rod body 7 is provided with threaded sections at set lengths, and the center of the split anti-floating anchor rod locator 8 is provided with a threaded through hole, and multiple split anti-floating anchor rod locators 8 are fixed to the anchor rod body 7 by threaded connection; the inner diameter of the split anti-floating anchor rod locator 8 is the same as the diameter of the anchor rod body 7, and the external expansion body is a cross rib type, the maximum width of the cross rib is the same as the diameter of the anchor hole 6, and the gaps generated at the four corners will ensure the circulation of the subsequent grouting slurry. The main function of the split anti-floating anchor rod locator 8 is to ensure that the distance between the anchor rod body 7 and the wall of the anchor hole 6 is the same during the lowering process of the anchor rod body 7, and it has the function of assisting centering. In this embodiment, threaded sections are arranged on the anchor rod body 7 every 2-2.5 meters.

[0059] Example 2

[0060] The present embodiment discloses a construction method for reserving a hole position for an anti-floating anchor rod in a foundation cushion layer, which uses a construction system for reserving a hole position for an anti-floating anchor rod in a foundation cushion layer disclosed in Embodiment 1, and specifically includes:

[0061] S1, setting the positioning steel bar 1 and installing the positioning tube 2;

[0062] S2, pouring construction of cushion layer 4;

[0063] S3, taking out the positioning steel bar 1 and the positioning tube 2 to form a positioning hole 5;

[0064] S4, drilling an anchor hole 6 in the positioning hole 5;

[0065] S5, installing the anchor rod body 7 and grouting;

[0066] S6. Construct waterproof layer and protective layer.

[0067] In step S1, a total station is used to accurately locate the overall leveling, a three-line laser level is used to lay out the lines all at once, and the total station is used to locate according to the designed position of the anchor rod body 7. The positioning steel bar 1 is fixed in the soil 3 at the positioning position, and the positioning tube 2 is placed on the soil 3 with the positioning steel bar 1 as the center point. Then, the vertical intersection of the two mutually perpendicular positioning steel wires 23 is aimed at the axis of the positioning steel bar 1; then, a square steel pad with four sides slightly longer than the diameter of the positioning tube 2 is horizontally placed on the top of the positioning tube 2, and the steel pad is hit with a hammer so that the four fixed steel bars 22 under the positioning tube 2 are completely inserted and fixed in the soil 3.

[0068] In step S3, after the cushion layer 4 has initially solidified, use a hammer to gently hammer the positioning tube 2. After the positioning tube 2 is peeled off and loosened from the cushion layer, lift the removal handle 24 with both hands to remove it, and then remove the positioning steel bar 1 to form a positioning hole 5, which is convenient for the subsequent construction of the anchor hole 6. At the same time, the positioning steel bar 1 and the positioning tube 2 can be reused. The formed positioning hole 5 is the second positioning measure for the position of the anchor hole 6. It should be noted that when the positioning steel bar 1 and the positioning tube 2 are taken out, it is necessary to ensure that the structure and flatness of the cushion layer 4 will not be damaged, so as to avoid the situation where the waterproof layer and the cushion layer 4 are not firmly bonded during the subsequent waterproof layer construction, reduce the hidden danger of water seepage in the foundation, and improve the waterproof performance of the foundation.

[0069] In step S4, after the positioning steel bar 1 and the positioning tube 2 are taken out and the positioning hole 5 is formed, the cushion layer 4 is cured for 7 days. After the cushion layer 4 is cured, the construction of the anchor hole 6 is started. In this embodiment, the diameter of the anchor hole 6 is 110 mm, and the diameter of the positioning hole 5 is 150 mm. The diameter of the anchor hole 6 is smaller than the diameter of the positioning hole 5, which can avoid damage to the cushion layer 4 due to vibration during the construction of the anchor hole 6.

[0070] The anchor hole 6 is constructed by a hydraulic down-the-hole drill. After drilling and cleaning, the anchor hole 6 is formed. Compared with ordinary drilling rigs, hydraulic down-the-hole drills have the advantages of higher efficiency, stronger adaptability, simple operation, and high safety. It should be noted that when the hydraulic down-the-hole drill is constructed on the cushion layer 4, a waste template must be set under its chain wheel as a pad to ensure that the cushion layer 4 will not be damaged.

[0071] In step S5, the anchor rod body 7 equipped with the split anti-floating anchor rod locator 8 is lowered into the anchor hole 6. After the anchor rod body 7 is installed, grouting is performed. The grouting adopts the bottom hole reverse pressure grouting method. The grouting pipe is inserted to 300mm from the bottom of the anchor hole 6. During the grouting process, the air is directly discharged from the orifice of the anchor hole 6. When the concentration of the discharged slurry is the same as the concentration of the injected slurry and does not contain bubbles, the grouting is completed. It should be noted that during grouting, the positioning hole 5 should be grouted together, and at the same time, the top surface of the grouting body should be kept flush with the top surface of the cushion layer 4 to avoid the situation where the waterproof layer and the cushion layer 4 are not firmly bonded during the subsequent waterproof layer construction, reduce the hidden danger of water seepage in the foundation, and improve the waterproof performance of the foundation.

[0072] In step S6, after the grouting body is completely solidified, the mud generated when the hydraulic down-the-hole drill constructs the anchor hole 6 on the cushion layer 4 is cleaned. After the cushion layer 4 is cleaned, the waterproof layer and the protective layer are constructed. After the waterproof layer and the protective layer are constructed, the connection nodes between the anchor rod body 7 and the cushion layer 4, and the waterproof layer and the protective layer are waterproofed. By setting water-swellable waterproofing strips and pouring non-curing waterproof coatings, the gaps and capillaries between the anchor rod body 7 and the cushion layer 4, and the waterproof layer and the protective layer are filled and closed, reducing the hidden danger of water seepage in the foundation and improving the waterproof performance of the foundation. After the node waterproofing treatment is completed, the entire construction process is completed.

[0073] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A construction system for reserving anti-floating anchor hole positions in a foundation cushion layer, characterized in that: It includes a plurality of positioning steel bars fixed in the soil, each positioning steel bar being located at the center of each anchor hole; Positioning tubes are set on the outside of the positioning steel bars, and the vertical projection of the center of the positioning tubes coincides with the positioning steel bars; a cushion layer is poured on the outside of the positioning tubes; After the cushion layer initially sets, the positioning tube is removed to form a positioning hole. An anchor hole is drilled in the positioning hole by a hydraulic down-the-hole drill. The center of the anchor hole is consistent with that of the positioning hole. The anchor hole is used to place the anchor rod body equipped with a split anti-floating anchor locator.

2. A construction system for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 1, characterized in that: The positioning tube comprises a steel cylinder, which is a hollow cylinder, with multiple fixed steel bars uniformly welded at the bottom of the steel cylinder and multiple positioning steel wires uniformly fixed at the top; the length of the positioning steel wires is equal to the diameter of the steel cylinder, and the intersection point between the positioning steel wires is the same as the center of the steel cylinder; A steel pad is placed on top of the positioning tube and then hammered into the steel pad to drive the fixing reinforcement into the soil.

3. A construction system for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 2, characterized in that: The height of the steel cylinder is at least 100 mm greater than the thickness of the cushion layer, and the height of the steel cylinder is greater than the length of the positioning steel bar.

4. A construction system for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 1, characterized in that: The outer wall diameter of the positioning tube is larger than the diameter of the anchor hole, and the thickness of the steel tube is larger than or equal to the diameter of the fixed steel bar.

5. A construction system for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 1, characterized in that: Threaded sections are arranged on the anchor rod body at set lengths, a threaded through hole is opened at the center of the split anti-floating anchor rod locator, the inner diameter of the split anti-floating anchor rod locator is the same as the diameter of the anchor rod body, and multiple split anti-floating anchor rod locators are fixed on the multiple threaded sections of the anchor rod body by threaded connection; the outer diameter of the split anti-floating anchor rod locator is the same as the diameter of the anchor hole.

6. A construction method for reserving anti-floating anchor hole positions in a foundation cushion layer, using a construction system for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in any one of claims 1 to 5, characterized in that: Specifically include: S1. Set the positioning steel bars and install the positioning pipes; S2, cushion layer pouring construction; S3, taking out the positioning steel bars and the positioning tube to form a positioning hole; S4, drilling anchor holes in the positioning holes; S5. Install the anchor rod body and grouting; S6. Construct waterproof layer and protective layer.

7. A construction method for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 6, characterized in that: In S1, a total station is used to locate the anchor rod according to its designed position, and the positioning steel bar is fixed in the soil at the positioning position. The positioning tube is placed on the soil with the positioning steel bar as the center point, and then the intersection of the positioning steel wires is aimed at the axis of the positioning steel bar; then a steel pad is placed horizontally on the top of the positioning tube, and the steel pad is hit with a hammer to make the fixing steel bar completely inserted and fixed in the soil.

8. A construction method for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 6, characterized in that: In S4, after the cushion layer is cured, a hydraulic down-the-hole drill is used to drill holes in the positioning holes, and after the holes are cleaned, anchor holes are formed. When the hydraulic down-the-hole drill is constructed on the cushion layer, a waste template must be set under its chain wheel as a pad.

9. A construction method for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 6, characterized in that: In S5, the anchor rod body equipped with the split anti-floating anchor rod positioner is lowered into the anchor hole, and grouting is performed after the anchor rod body is installed, and the grouting adopts the bottom hole reverse pressure grouting method; When grouting, the positioning holes should be grouted at the same time to ensure that the top surface of the grouting body is flush with the top surface of the cushion layer.

10. A construction method for reserving anti-floating anchor hole positions in a foundation cushion layer as claimed in claim 6, characterized in that: In S6, after the grouting body is completely solidified, the mud generated when constructing the anchor holes on the cushion layer is cleaned, and then the waterproof layer and the protective layer are constructed; finally, a water-swellable water-stop strip is set and a non-curing waterproof coating is poured to fill and seal the gaps and capillaries between the anchor rod body and the cushion layer, and between the waterproof layer and the protective layer.

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