A method for reinforcing water seepage deformation of basement waterproofing board

Abstract

The present invention belongs to the technical field of building construction, and relates to a method for reinforcing water seepage deformation of a basement waterproofing board. The method comprises the following steps: a plurality of prestressed anchor rods and non-prestressed anchor rods are evenly distributed in a criss-cross pattern in a water seepage deformation zone; the prestressed anchor rods are used to completely restore the deformed original waterproofing board, and then the non-prestressed anchor rods are used to fix and maintain the board; a steel plate belt is used to strengthen the fixing and maintaining effect; finally, a fine stone concrete protective layer and a leveling layer are covered on the anchor rods and the steel plate belt; the method of the present invention is faster and more efficient in reinforcing the water seepage deformation of the waterproofing board, and the repair quality is long-lasting and effective.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction and relates to a method for reinforcing water seepage deformation of a basement waterproofing board. Background Art

[0002] In the prior art, when the basement of a building seeps water due to moisture, the floor and waterproof board partially or completely warp, deform, crack, seep and leak, seriously affecting the safe use of the building, the method usually adopted is to clean the seeping and leaking parts and then re-lay the construction, which is a large amount of work and the treatment effect is not good. In particular, for the seepage and deformation of the floor in the basement, it is very difficult to reinforce and repair the waterproof board in the existing building due to the small space and difficult construction conditions of the equipment.

[0003] Therefore, there is a need for a faster, more efficient and quality-assured method of treating water seepage and leakage in basement waterproofing panels to solve this construction problem. Summary of the invention

[0004] The technical solution adopted by the present invention to solve the technical problem is: a method for reinforcing water seepage deformation of a basement waterproofing board, comprising the following steps:

[0005] Step 1: Perform stress analysis and calculation based on the soil properties of the site, the bearing capacity of the foundation, the overview of the original structural foundation, the thickness of the original waterproofing board, the seepage deformation area and the deformation size, and then select the location and spacing of the anchor holes, as well as the size, shape and dimensions of the prestressed anchors, non-prestressed anchors, steel anchor plates and steel strips used for reinforcement;

[0006] Step 2: Drilling anchor holes, drilling according to the position, spacing and anchor size of the anchor holes obtained in step 1;

[0007] Step 3: According to the size, shape and dimensions of the prestressed anchor rods and non-prestressed anchor rods obtained in step 1, the steel bars of the selected prestressed anchor rods and non-prestressed anchor rods are fixed in the anchor rod holes, and the first grouting of the anchor rods is performed. The height of the first grouting of the anchor rods is the height of the original plain concrete pad at the bottom of the original waterproof board. The prestressed anchor rods and non-prestressed anchor rods are arranged alternately at intervals, and the outermost circle of anchor rods in the deformation area of ​​the original waterproof board are all non-prestressed anchor rods;

[0008] Step 4: Remove the mud and sand mixed under the original waterproof board, and perform waterproof repair under the waterproof board;

[0009] Step 5: Apply prestress to the deformed area of ​​the original waterproof board around the prestressed anchor rod by tightening the steel anchor plate through the prestressed anchor rod, so that the deformed area of ​​the original waterproof board is completely restored to flatness;

[0010] Step 6: Perform the second grouting on the non-prestressed anchor rods, seal the non-prestressed anchor rods and anchor the anchor bars, so that the non-prestressed anchor rods can play a reinforcing role in anchoring the deformed area of ​​the original waterproof board that has been completely restored to a flat surface;

[0011] Step 7: Remove the prestress of the prestressed anchor rod, replace the stress of the prestressed anchor rod on the waterproof board with a non-prestressed anchor rod, then grout the prestressed anchor rod for the second time, seal the prestressed anchor rod and anchor the anchor bar, and finally make the prestressed anchor rod and the non-prestressed anchor rod jointly anchor and reinforce the deformed area of ​​the original waterproof board;

[0012] Step 8: Grind, clean and level the original waterproof board under the steel strip, apply Class A structural adhesive and stick the steel strip to the original waterproof board. After all the steel strips are pasted, weld the steel strip to the steel anchor plates on the two adjacent anchor rods until all the steel anchor plates in the deformation area of ​​the original waterproof board are connected as a whole.

[0013] Step 9: Use epoxy resin flexible grouting liquid to repair the local cracks and fissures on the original waterproof board;

[0014] Step 10: Apply a polymer cement-based waterproof layer on the entire upper surface of the original waterproof board after the grouting repair is completed;

[0015] Step 11: Lay a coating isolation layer on the polymer cement-based waterproof layer;

[0016] Step 12: Lay a fine stone concrete protective layer and leveling layer on the upper surface of the coating isolation layer. The fine stone concrete protective layer and leveling layer is required to completely cover the anchor rod steel bar head, steel anchor plate and steel plate strip to complete the reinforcement of the waterproof board against water seepage and deformation.

[0017] Preferably, in step one, the inner steel bar of the prestressed anchor rod is a single steel bar, the upper end of the inner steel bar of the prestressed anchor rod is provided with a thread, and the thread is provided with a nut anchor for applying prestress.

[0018] Preferably, in step one, the inner steel bars of the non-prestressed anchor rod are 2 to 4 steel bars spot-welded into a bundle, and the steel anchor plate is sleeved on the upper end of the inner steel bars of the non-prestressed anchor rod. During anchoring and reinforcement, the 2 to 4 steel bars at the upper end of the inner steel bars of the non-prestressed anchor rod are evenly bifurcated, bent, and welded to connect the steel anchor plate.

[0019] Preferably, in step 2, the anchor holes are drilled in a manner evenly distributed vertically and horizontally in the deformed area of ​​the original waterproof board.

[0020] Preferably, in the step 2, in order to prevent the hole from being skewed, a slow impact is adopted when opening the hole; a uniform and slow advance is adopted during the punching and drilling process, and when encountering large resistance, the down-the-hole hammer is lifted upward, and the lifting distance is about 0.30-0.50 meters, and the penetration is impacted again with the rotating vibration. After the hole is drilled to a certain depth, the drill cuttings are removed until the hole depth reaches the requirement; after the anchor hole is formed, the air duct connected to the air compressor is placed in the hole, and it is repeatedly flushed from top to bottom and then from bottom to top to ensure that there is no debris in the hole.

[0021] Preferably, in step three, the first grouting of the anchor rod is carried out by the bottom grouting method, the grouting outlet of the grouting pipe should be inserted 300-500mm from the bottom of the hole, and the slurry is continuously poured from bottom to top; the grouting pipe should be pulled out while grouting, and the pulling height should not exceed the slurry surface in the hole until the required anchor section height is reached.

[0022] Preferably, in step five, prestress is applied in the order of anchor rod construction starting from the mid-span position of the deformation area of ​​the original waterproof board to the surrounding anchor rods. The prestress is applied manually, and the application of prestress should ensure that the stress of the prestressed anchor rods is applied evenly and synchronously as much as possible to ensure that the deformation of the deformation area of ​​the original waterproof board is completely restored to flatness.

[0023] Preferably, in step ten, the polymer cement-based waterproof layer is applied twice, with a total thickness of 1.0 mm, and the surrounding walls are 0.5 meters high.

[0024] Preferably, in step twelve, the fine stone concrete protective layer and leveling layer is made of 40 mm thick C25 fine stone concrete material.

[0025] The beneficial effects of the present invention are:

[0026] The present invention evenly distributes a plurality of prestressed anchor rods and non-prestressed anchor rods in a criss-cross pattern in the water seepage deformation zone, uses the prestressed anchor rods to completely restore the deformed original waterproof board, and then uses the non-prestressed anchor rods to fix and maintain it, then uses steel plate strips to strengthen the fixing and maintaining effect, and finally covers the anchor rods and the steel plate strips with a fine stone concrete protective layer and a leveling layer; the structural reinforcement of the waterproof board with water seepage deformation of the present invention is faster and more efficient, and the repair quality is long-lasting and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a plan view of anchor arrangement for a method of reinforcing a basement waterproofing board for water seepage and deformation;

[0028] Figure 2 is a schematic diagram of a prestressed anchor rod;

[0029] Figure 3 It is a schematic diagram of non-prestressed anchor;

[0030] Figure 4 It is a plan view of the steel strip reinforcement arrangement;

[0031] Figure 5 This is a schematic diagram of the bending and welding of non-prestressed anchor reinforcement;

[0032] Figure 6 This is a schematic diagram of waterproof reinforcement repair.

[0033] In the figure, 1. Prestressed anchor rod; 2. Non-prestressed anchor rod; 3. Steel anchor plate; 4. Steel plate strip; 5. Original waterproof board; 6. Fine stone concrete protective layer and leveling layer; 7. Polymer cement-based waterproof layer. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technologies in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] refer to Figures 1 to 6 , a method for reinforcing water seepage deformation of a basement waterproofing board, comprising the following steps:

[0036] Step 1: Perform stress analysis and calculation based on the soil properties of the site, the bearing capacity of the foundation, the overview of the original structural foundation, the thickness of the original waterproof board 5, the seepage deformation area and the deformation size, and then select the location and spacing of the anchor holes, as well as the size, shape and dimensions of the prestressed anchor 1, non-prestressed anchor 2, steel anchor plate 3, and steel plate belt 4 for reinforcement;

[0037] Step 2: Drilling anchor holes, drilling according to the position, spacing and anchor size of the anchor holes obtained in step 1;

[0038] Step 3: According to the size, shape and dimensions of the prestressed anchor rod 1 and the non-prestressed anchor rod 2 obtained in step 1, the selected steel bars of the prestressed anchor rod 1 and the non-prestressed anchor rod 2 are fixed in the anchor rod hole, and the first grouting of the anchor rod is performed. The height of the first grouting of the anchor rod is the height of the original plain concrete pad at the bottom of the original waterproof board 5. The prestressed anchor rod 1 and the non-prestressed anchor rod 2 are arranged alternately at intervals, and the outermost circle of anchor rods in the deformation area of ​​the original waterproof board 5 are all non-prestressed anchor rods 2;

[0039] Step 4: Remove the mud and sand mixed under the original waterproof board 5, and perform waterproof repair under the waterproof board;

[0040] Step 5: Apply prestress to the deformed area of ​​the original waterproof board 5 around the prestressed anchor rod 1 by tightening the steel anchor plate 3, so that the deformed area of ​​the original waterproof board 5 is completely restored to flatness;

[0041] Step 6: grouting the non-prestressed anchor rod 2 for the second time, sealing the non-prestressed anchor rod 2 and anchoring the anchor bar, so that the non-prestressed anchor rod 2 plays a reinforcing role in anchoring the deformed area of ​​the original waterproof board 5 that has been completely restored to a flat state;

[0042] Step 7: Remove the prestress of the prestressed anchor rod 1, replace the stress of the prestressed anchor rod 1 on the waterproof board with the non-prestressed anchor rod 2, then grout the prestressed anchor rod 1 for the second time, seal the prestressed anchor rod 1 and anchor the anchor bar, and finally make the prestressed anchor rod 1 and the non-prestressed anchor rod 2 jointly anchor and reinforce the deformed area of ​​the original waterproof board 5;

[0043] Step 8: Grind, clean and level the original waterproof board 5 under the steel strip 4, apply A-grade structural adhesive to stick and reinforce the steel strip 4 on the original waterproof board 5, and after all the steel strips 4 are pasted, weld the steel strip 4 to the steel anchor plates 3 on the two adjacent anchor rods until all the steel anchor plates 3 in the deformation area of ​​the original waterproof board 5 are connected as a whole;

[0044] Step nine: Use epoxy resin flexible grouting liquid to repair the local cracks and fissures on the original waterproof board 5;

[0045] Step 10: Apply a polymer cement-based waterproof layer 7 to the entire upper surface of the original waterproof board 5 after the grouting repair is completed;

[0046] Step 11: Laying a coating isolation layer on the polymer cement-based waterproof layer 7;

[0047] Step 12: Lay a fine stone concrete protective layer and leveling layer 6 on the upper surface of the coating isolation layer. The fine stone concrete protective layer and leveling layer 6 is required to completely cover the anchor rod steel bar head, steel anchor plate 3 and steel plate strip 4 to complete the reinforcement of the waterproof board against water seepage and deformation.

[0048] Furthermore, in the step 1, the inner steel bar of the prestressed anchor rod 1 is a single steel bar, and the upper end of the inner steel bar of the prestressed anchor rod 1 is provided with a thread, and a nut anchor is provided on the thread for applying prestress.

[0049] Furthermore, in the step one, the inner steel bars of the non-prestressed anchor rod 2 are 2 to 4 steel bars spot-welded into a bundle, and the steel anchor plate 3 is sleeved on the upper end of the inner steel bars of the non-prestressed anchor rod 2. During anchoring and reinforcement, the 2 to 4 steel bars at the upper end of the inner steel bars of the non-prestressed anchor rod 2 are evenly bifurcated, bent, and welded to connect the steel anchor plate 3.

[0050] Furthermore, in the step 2, the anchor holes are drilled in a manner uniformly distributed vertically and horizontally in the deformation area of ​​the original waterproof board 5 .

[0051] Furthermore, in the step 2, in order to prevent the hole from being skewed, slow impact is adopted when opening the hole; a uniform and slow advance is adopted during the punching and drilling process, and when encountering great resistance, the down-the-hole hammer is lifted upward, and the lifting distance is about 0.30-0.50 meters, and the penetration is impacted again with the rotating vibration. After the hole is drilled to a certain depth, the drill cuttings are removed until the hole depth reaches the requirement; after the anchor hole is formed, the air duct connected to the air compressor is placed in the hole, and flushed repeatedly from top to bottom and then from bottom to top to ensure that there is no debris in the hole.

[0052] Furthermore, in step three, the first grouting of the anchor rod is carried out by the bottom grouting method, the grouting outlet of the grouting pipe should be inserted 300-500mm from the bottom of the hole, and the slurry is continuously poured from bottom to top; the grouting pipe should be pulled out while grouting, and the pulling height should not exceed the slurry surface in the hole until the required anchor section height is reached.

[0053] Furthermore, in the step five, the prestress is applied in the order of starting from the anchor rod at the mid-span position of the deformation area of ​​the original waterproof board 5 to the surrounding anchor rods. The prestress is applied manually. The application of prestress should ensure that the stress of the prestressed anchor rod 1 is applied evenly and synchronously as much as possible to ensure that the deformation of the deformation area of ​​the original waterproof board 5 is completely restored to flatness.

[0054] Furthermore, in the step 10, the polymer cement-based waterproof layer 7 is applied twice, with a total thickness of 1.0 mm, and the surrounding walls are 0.5 meters high.

[0055] Furthermore, in the step 12, the fine stone concrete protective layer and leveling layer 6 is made of 40 mm thick C25 fine stone concrete material.

[0056] Example

[0057] This embodiment is an art museum in a certain city, with a total construction area of ​​5500 square meters, of which three floors above ground total 2553 square meters, and part of the second floor underground total 2947 square meters. The underground first floor and its mezzanine are mainly used as equipment rooms, temporary exhibition halls, multimedia demonstration halls, multi-functional lecture halls, restoration rooms, offices, collection warehouses, etc.; the main function of the first floor above ground is the exhibition hall, and auxiliary rooms such as duty, reception, calligraphy and painting classrooms are arranged; the second floor is a calligraphy and painting exhibition hall; the third floor is a boutique exhibition hall.

[0058] The project started construction in June 2016, and the main part was completed in June 2017. It then entered the installation and decoration stage. In November of the same year, the waterproofing board of the basement of the art museum was hit by an unexpected high head water pressure. The waterproofing board of the multifunctional lecture hall at the basement elevation of -7.000m was partially warped, deformed, cracked, and leaked, seriously affecting the safe use of the project. The original design used two layers of polymer cement waterproofing membrane for the basement external waterproofing.

[0059] Analysis of the cause of water seepage: According to the geological exploration report of the project, groundwater in the site only exists at -12.0m below the surface. The surface layer of the project site is 0.5 to 1.2m thick of miscellaneous fill, below which is a rock layer composed of strongly weathered soil 1.0m to 6.0m thick, and below which is slightly weathered soil. The thickness of the slightly weathered rock layer has not been penetrated.

[0060] According to subsequent investigation and analysis, the entire project is located in a hilly area. There was no groundwater from the excavation of the foundation pit in June 2016 to the completion of the entire main structure in June 2017. It was not until November 2017 that water suddenly appeared underground. According to analysis, the water source may come from the mountain stream system or from the leakage of the reservoir on the high ground on the north side of the project. The water head height is about 1.5m high, which is basically consistent with the depth of the building basement foundation buried in the strongly weathered rock layer. Because this part of groundwater has nowhere to seep in the rock layer, it gathers and generates upward buoyancy on the building. Its buoyancy is about 1.5m*10KN / m 3 =15KN / m 2 , less than the base pressure of the entire building waterproof board (70KN / m 2 ). The entire building will not float up and is safe. However, this buoyancy will generate a large internal force on the waterproof board of the basement, especially for the waterproof board with a large span. This is the reason for the deformation, warping, cracking and water seepage of the waterproof board in the multi-functional lecture hall.

[0061] Reinforcement plan: After on-site investigation and accident cause analysis and inference, it was determined that the waterproof bottom plate of the basement of the art museum would be reinforced as follows, and the reinforcement and repair construction would be carried out in the following steps:

[0062] 1. Precipitation of water at well points outside buildings;

[0063] (ii) Strengthening of basement waterproofing structure;

[0064] (iii) Repair of leakage and waterproofing of waterproofing boards;

[0065] Well point precipitation outside the building: Before reinforcement, the groundwater around the building should be drained to ensure that there is no open water in the room during the reinforcement and repair of the waterproof board in the basement of the art museum. The precipitation adopts the well point precipitation plan. Set up precipitation wells around the basement of the building, and use water pumps to pump water to the nearby municipal rainwater wells. For the outdoor precipitation plan and construction details, please refer to the construction plan.

[0066] Anchor reinforcement of basement waterproofing board; engineering geology and site topography and geomorphic features. The site is located in the transition zone from Changbai Mountain to Songnen Plain, which is a low hilly landform. The overall terrain of the site is high in the north and low in the south, high in the east and low in the west. This project is located at the low part of the slope.

[0067] According to the results of the survey report, there is no macroscopic adverse geological effect, the site area is relatively stable and suitable for engineering construction. The soil layer distribution of the site is as follows:

[0068] The first layer of miscellaneous fill soil: 0.4 to 1.4 meters thick, with poor engineering properties;

[0069] The second layer of fully weathered granite: the core is gravel-like, with a thickness of 1.4 to 6.6 meters, and good engineering properties; the characteristic value of foundation bearing capacity is 300 Kpa

[0070] The third layer is highly weathered granite: the engineering properties are good, the characteristic value of foundation bearing capacity is 600Kpa, and there is no weak layer underneath. No groundwater was found during the survey.

[0071] Overview of the original structure foundation: The foundation depth of this embodiment is -4m to -7m, the surface fill soil of the foundation has been completely excavated, and the base has reached the second layer of fully weathered granite. This embodiment uses a natural foundation. The current status of the foundation pit excavation is completely consistent with the geological survey.

[0072] The structural system adopts a reinforced concrete frame structure, the foundation form adopts an independent foundation under reinforced concrete columns plus a 250mm thick concrete waterproof slab, and a concrete strip foundation is used under the surrounding concrete retaining walls.

[0073] The waterproof board reinforcement is Φ12@200 double-layer and bidirectional, with P6 water resistance grade.

[0074] Waterproof board anchor rod design scheme: According to the actual situation on site, the design adopts rock anchor rod + steel plate bonding to reinforce and repair the waterproof board. A total of 55 anchor rods are designed and constructed, see the following design anchor rod layout diagram for details:

[0075] There are 41 non-prestressed anchor rods 2 and 14 prestressed anchor rods 1. Figure 1 As shown. To estimate the pull-out bearing capacity characteristic value of a single anchor rod, the following calculations are required: (1) Calculation of rod strength. (2) Calculation of shear strength between the mortar body and the rock and soil layer. (3) Calculation of bond strength between the anchor rod body and the grouting body. The smaller value of the above three calculation results is taken as the pull-out bearing capacity characteristic value of a single anchor rod. The following calculations for the anchor rod of this project are as follows:

[0076] Due to the limitation of the construction space in the basement, this embodiment adopts a small diameter Φ100 anchor rod, and the anti-floating head height is designed to be 1.5m high. The characteristic value of its pull-out bearing capacity is calculated as follows:

[0077] The area of ​​the multifunctional lecture hall is A = 11.67m*17.1m*=199.6㎡, take 200㎡

[0078] Water buoyancy: F=200㎡*15KN / ㎡*1.2=3600KN

[0079] Number of anchor rods: n=3600KN / 70=51.4, actual arrangement n=55

[0080] Characteristic value of pull-out bearing capacity: Nak=3600KN / 55 roots=65.5KN

[0081] According to the actual calculation, Nak=70KN is taken, the reinforcement of the reinforcement is HRB400, and fy=360N / ㎡.

[0082] (1) Calculation of steel bar area (according to Article 8.2.2 of Technical Specification for Building Slope Engineering GB50330-2013)

[0083] As≥(Kb * Nak) / fy =(2.0*70*10^3) / 360=380mm 2

[0084] One 22 steel bar can be used, As=380mm 2

[0085] (2) Anchorage length between anchor bolt and ground (according to Article 8.2.3 of Technical Specification for Slope Engineering GB50330-2013)

[0086] La ≥(K * Nak) / (π* D* frbk)

[0087] =2.4*70 / (3.14*100*0.2)=2.68m

[0088] (3) Anchorage length between anchor reinforcement and anchor mortar (according to Article 8.2.4 of Technical Specification for Slope Engineering GB50330-2013)

[0089] La ≥(K * Nak) / (n*π* d* fb)

[0090] =2.4*70 / (1*3.14*22*2.4)=1.01m

[0091] Taking all the above factors into consideration, the length of a single anchor rod entering the rock is La≥3.50m.

[0092] Consolidation body: This embodiment uses 30MPa cement slurry, and the strength grade meets the design and national standard requirements.

[0093] Anchor rods: There are two types: prestressed anchor rods 1 and non-prestressed anchor rods 2. The full-length bonded non-prestressed anchor rods 2 use anchor bars 2φ16 (HRB400) and are spot welded into bundles; the total number is 41. Figure 3 As shown in the figure. The prestressed anchor rod 1 uses anchor bar 1φ22 (HRB400), and the total number of anchor rods is 14. Figure 2shown.

[0094] All anchor rods are grouted with cement slurry. In this embodiment, 30MPa cement slurry is used, which is grouted twice. The outlet of the grouting pipe should be inserted 300-500mm from the bottom of the hole. The cement slurry is continuously grouted from bottom to top, and it is ensured that the hole is drained and exhausted smoothly. The first grouting height is to the bottom of the cushion layer of the original waterproof board 5. The prestressed anchor rod 1 is grouted once before prestressing. After the prestressing is completed, the second grouting is performed.

[0095] The plan layout and detailed drawings of anchor rods are constructed according to the requirements in the above figure. The characteristic value of the pull-out bearing capacity of the anchor rod is controlled at Nak=70KN.

[0096] Anchor bolt construction process flow; a. Non-prestressed anchor bolt 2 construction process flow: anchor hole positioning number → drilling rig in place → drilling → anchoring → grouting and pulling out the pipe → secondary grouting → anchor sealing. b. Prestressed anchor bolt 1 construction process flow: anchor hole positioning number → drilling rig in place → drilling → anchoring → grouting and pulling out the pipe → maintenance → anchor bolt tensioning and locking → secondary grouting → anchor sealing.

[0097] Anchor bolt construction process; 1) Anchor bolt hole construction equipment: Hole forming machine: Since the drilling construction is limited by the basement space, it is determined to use a small, portable, fully pneumatic down-the-hole hammer drill to form the hole, and the hole diameter is Φ100, and an air compressor and other equipment are also equipped. 2) Drilling line positioning: According to the construction anchor bolt plan layout, the hole position is determined by laying out the line, marking and pre-inspection are done. 3) Anchor bolt hole forming: Install the anchor hole drilling rig, level, adjust the vertical position, and stabilize it. Start the air compressor. When the air pressure reaches a certain pressure, the down-the-hole hammer forms a rotating vibration, and the drilling rig power head is started for punching and drilling. In order to prevent the hole from being biased, slow impact should be adopted when opening the hole; during the punching and drilling process, a uniform and slow advance is adopted. When encountering large resistance, the down-the-hole hammer is lifted upward, and the lifting distance is about 0.30-0.50 meters. It is again impacted with the rotation and vibration. After the hole is drilled to a certain depth, the drill residue is removed until the hole depth reaches the design requirement. After the hole reaches the designed depth, the bottom of the down-the-hole hammer is cleaned by air pressure for 2-3 minutes, and the sediment is removed as the drill pipe is lifted.

[0098] The anchor hole diameter is 100mm, the hole diameter deviation is no more than 2cm, the drilling depth deviation should not be less than 1% of the design depth, nor should it be greater than 500mm of the design depth, and the hole depth should meet the design requirements;

[0099] After the anchor hole is formed, the air duct connected to the air compressor is placed in the hole, and flushed repeatedly from top to bottom and then from bottom to top to ensure that there is no debris in the hole;

[0100] Anchor rod processing and installation in the hole: Non-prestressed anchor rod 2 is 2Φ16 (HRB400), and the main reinforcement is spot welded into a bundle; prestressed anchor rod 1 is 1Φ22 (HRB400). In order to apply prestress to the end of the prestressed reinforcement, it is necessary to use a thread with a nut that can be tightened at the upper end of the prestressed reinforcement, and the thread must be long enough to ensure that the nut stroke can reset the waterproof board when the prestress is applied. The thread length L ≥ 350mm.

[0101] Anchor primary grouting: The anchor section grouting adopts the hole bottom return grouting method. The grouting outlet of the grouting pipe should be inserted 300-500mm from the bottom of the hole, and the slurry is continuously poured from bottom to top. The grouting pipe should be pulled out while grouting, and the pulling height should not exceed the slurry surface in the hole until the anchor section height required by the design is reached, that is, the lower surface height of the plain concrete cushion layer under the original waterproof board 5.

[0102] Cleaning of waterproof board: After the initial grouting of the anchoring section in the anchor hole has set, start the grouting pump and use clean water to flush the mud in the anchor hole and the mud on the entire indoor waterproof board, especially the mud and sand in the hollow area at the bottom of the waterproof board should be cleaned.

[0103] Waterproof repair of waterproof board: Use flexible waterproof liquid such as Pengneichuan cement-based grouting liquid (PNC901) to fill the gaps and cracks under the waterproof board. Waterproof repair is performed locally on the lower part of the waterproof board around the anchor rod drilling hole.

[0104] Application of prestress: After the mortar strength of the anchor body of the prestressed anchor rod 1 reaches 100% of the design strength, install the steel anchor plate 3, i.e. the pressure plate, according to the design requirements and layout of the prestressed anchor rod 1, and tighten the nut to apply prestress to the free section reinforcement. According to the construction sequence from the anchor rod at the mid-span position of the plate to the anchor rods around, the prestress is applied manually by tightening the nut. The application of prestress should try to ensure that the stress of the 14 prestressed anchor rods 1 is applied evenly and synchronously, and ensure that the deformation of the waterproof board is completely restored to flatness.

[0105] Secondary grouting of non-prestressed anchor rod 2: After completing the stress construction of all prestressed anchor rods 1, the secondary grouting of non-prestressed anchor rod 2 can be carried out. The mortar requirements are the same as before and the sealing of non-prestressed anchor rod 2 and anchoring of anchor bars are completed according to the design requirements. Epoxy resin mortar is used at the grouting port of the anchor rod hole to firmly and densely stick the anchor plate.

[0106] Secondary grouting of prestressed anchor rod 1: After completing the secondary grouting of non-prestressed anchor rod 2 and anchoring of anchor bars, non-prestressed anchor rod 2 can replace the stress of prestressed anchor rod on waterproof board. The anchor (anchor plate and nut) of prestressed anchor rod 1 can be removed to release the previous prestress of the tendon body, and secondary grouting is performed to the top of the waterproof board. After the anchor plate is firmly and densely attached to the grouting port of the anchor rod hole, the tendon body is bent and welded to the anchor plate as a whole. Figure 5 shown.

[0107] Structural reinforcement and waterproof repair of waterproof board: 1. Structural reinforcement of waterproof board, using steel strip 4 (1800*100*5) according to the size and layout required by the design, first grind, clean and level the waterproof board under the steel strip 4, then apply A-grade structural adhesive to stick and reinforce the steel strip 4 on the waterproof board. After all the steel strips 4 are pasted, the steel strip 4 is welded to the anchor plate on the anchor rod as a whole. 2. Waterproof repair of waterproof board: For local cracks and cracks on the waterproof board, epoxy resin flexible grouting liquid is used for grouting repair. After the structural reinforcement of the waterproof board and the grouting repair of its cracks, it is necessary to apply polymer cement-based (Pengneichuan cement-based PNC401) waterproof coating on the surface of the waterproof board twice, with a total thickness of 1.0mm. The wall height on all sides is 0.5 meters. After the surface waterproof construction is completed, 300g polypropylene is used to construct a moisture-proof layer and also as a coating isolation layer. Then, a 40mm thick C25 fine stone concrete material is used as a protective layer and a leveling layer to cover the anchor bar steel bar head and the steel plate belt 4 to complete the reinforcement and waterproof repair of the waterproof board. Only then can the interior decoration surface layer be constructed on it.

[0108] The construction of this embodiment started in November 2017 and was fully completed in March 2018. The project has been in use for 5 years and there has been no water seepage in the basement waterproofing board. The structural reinforcement and waterproof repair of the basement waterproofing board in this project have the following advantages and characteristics:

[0109] 1) A small diameter anchor system is used, the stress of a single anchor is small, and the anti-buoyancy stress of the waterproof board is evenly distributed.

[0110] 2) Prestressed anchor rods 1 and non-prestressed anchor rods 2 are used at the same time, and after the prestressed anchor rods 1 have completed the reinforcement effect, they are converted to non-prestressed anchor rods 2 to eliminate the prestress.

[0111] 3) The use of secondary grouting anchors greatly improves and enhances the structural durability of anchors. It eliminates the unfavorable factor that the free section of prestressed anchor bars is difficult to protect. The anchor system used not only solves the structural reinforcement of the waterproof board, but also strengthens its anti-floating and anti-pulling capabilities.

[0112] 4) Adhere the steel strip 4 to reinforce the waterproof board, and the connection between the steel strip 4 and the anchor bearing plate can play their respective roles, so that the anti-floating and anti-bending capabilities of the waterproof board are improved.

[0113] 5) In case of damage to the waterproof board, crack grouting repair and additional waterproof coating on the waterproof board are effective waterproof measures.

[0114] Construction:

[0115] 1) In view of the construction environment and space limitations, a small-sized, fully pneumatic down-the-hole hammer drilling equipment is used. The hole diameter is Φ100 and the hole depth can reach 4m. The equipment is convenient and flexible to construct and small in size, suitable for drilling holes in various rock formations. For construction in the basement space of an existing building, the use of this equipment is both convenient and reliable.

[0116] 2) Use small diameter bored anchor rods evenly arranged at 2m*2m intervals to facilitate the removal of mud and sand in the hollows under the waterproof board, with minimal damage to the waterproof layer under the waterproof board, and grouting repair is relatively easy.

[0117] 3) Apply polymer cement-based waterproof materials on the entire surface of the waterproof board to enhance the waterproof performance of the basement waterproof board. The actual effect is good after 5 years of use.

[0118] In summary, the present invention provides a method for reinforcing water seepage deformation of a basement waterproof board, by evenly distributing a plurality of prestressed anchor rods and non-prestressed anchor rods in a criss-cross pattern in the water seepage deformation zone, using prestressed anchor rods to fully restore the deformed original waterproof board, and then using non-prestressed anchor rods to fix and maintain it, and then using steel plate strips to strengthen the fixing and maintaining effect, and finally covering the anchor rods and the steel plate strips with a fine stone concrete protective layer and a leveling layer; the structural reinforcement of the water seepage deformation of the waterproof board of the present invention is faster and more efficient, and the repair quality is long-lasting and effective. After reinforcement, the thickness of the surface layer of the original waterproof board is only increased by about 50 mm, which has little effect on use. Therefore, the present invention has broad application prospects.

[0119] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for reinforcing water seepage deformation of basement waterproofing board, characterized in that: The steps include: Step 1: Perform stress analysis and calculation based on the soil properties of the site, the bearing capacity of the foundation, the overview of the original structural foundation, the thickness of the original waterproofing board (5), the seepage deformation area and the deformation size, and then select the location and spacing of the anchor holes, as well as the size, shape and dimensions of the prestressed anchors (1), non-prestressed anchors (2), steel anchor plates (3) and steel plate strips (4) used for reinforcement; Step 2: Drilling anchor holes, drilling according to the position, spacing and anchor size of the anchor holes obtained in step 1; Step 3: According to the size, shape and dimensions of the prestressed anchor rod (1) and the non-prestressed anchor rod (2) obtained in step 1, the selected steel bars of the prestressed anchor rod (1) and the non-prestressed anchor rod (2) are fixed in the anchor rod hole, and the first grouting of the anchor rod is performed. The height of the first grouting of the anchor rod is the height of the original plain concrete pad at the bottom of the original waterproof board (5). The prestressed anchor rod (1) and the non-prestressed anchor rod (2) are arranged in an interlaced manner, and the outermost circle of anchor rods in the deformation area of ​​the original waterproof board (5) are all non-prestressed anchor rods (2); Step 4: Remove the mud and sand mixed under the original waterproof board (5), and perform waterproof repair under the waterproof board; Step 5: Prestress is applied to the deformed area of ​​the original waterproof board (5) around the prestressed anchor rod (1) by tightening the steel anchor plate (3), so that the deformed area of ​​the original waterproof board (5) is completely restored to flatness; Step 6: grouting the non-prestressed anchor rod (2) for the second time, sealing the non-prestressed anchor rod (2) and anchoring the anchor bar, so that the non-prestressed anchor rod (2) plays a reinforcing role in anchoring the deformed area of ​​the original waterproof board (5) that has been completely restored to a flat state; Step 7: Remove the prestress of the prestressed anchor rod (1), replace the stress of the prestressed anchor rod (1) on the waterproof board with the non-prestressed anchor rod (2), then perform a second grouting on the prestressed anchor rod (1), seal the prestressed anchor rod (1) and anchor the anchor bar, and finally make the prestressed anchor rod (1) and the non-prestressed anchor rod (2) jointly anchor and reinforce the deformed area of ​​the original waterproof board (5); Step 8: Grind, clean and level the original waterproof board (5) under the steel strip (4), apply Class A structural adhesive, and adhere the steel strip (4) to the original waterproof board (5) for reinforcement. After all the steel strips (4) are adhered, weld the steel strip (4) to the steel anchor plates (3) on the two adjacent anchor rods until all the steel anchor plates (3) in the deformation area of ​​the original waterproof board (5) are connected as a whole. Step 9: Repair the local cracks and fissures on the original waterproof board (5) by grouting with an epoxy resin flexible grouting liquid; Step 10: After the grouting repair is completed, a polymer cement-based waterproof layer (7) is applied to the entire upper surface of the original waterproof board (5); Step 11: Laying a coating isolation layer on the polymer cement-based waterproof layer (7); Step 12: laying a fine stone concrete protective layer and leveling layer (6) on the upper surface of the coating isolation layer, requiring the fine stone concrete protective layer and leveling layer (6) to completely cover the anchor rod reinforcement head, the steel anchor plate (3) and the steel plate strip (4), so as to complete the reinforcement of the waterproof plate against water seepage and deformation; In the second step, the anchor holes are drilled in a manner that is evenly distributed vertically and horizontally in the deformed area of ​​the original waterproof board (5).

2. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In step 1, the inner steel bar of the prestressed anchor rod (1) is a single steel bar, the upper end of the inner steel bar of the prestressed anchor rod (1) is provided with a thread, and a nut anchor is provided on the thread for applying prestress.

3. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In the step 1, the inner steel bars of the non-prestressed anchor rod (2) are 2 to 4 steel bars spot-welded into a bundle, and the steel anchor plate (3) is sleeved on the upper end of the inner steel bars of the non-prestressed anchor rod (2). During anchoring and reinforcement, the 2 to 4 steel bars at the upper end of the inner steel bars of the non-prestressed anchor rod (2) are evenly forked, bent, and welded to the steel anchor plate (3).

4. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In the step 2, in order to prevent the hole from being skewed, slow impact is adopted when opening the hole; uniform and slow advance is adopted during the punching and drilling process, and when encountering great resistance, the down-the-hole hammer is lifted upward, and the lifting distance is 0.30-0.50 meters, and the penetration is impacted again with the rotating vibration. After the hole is drilled to a certain depth, the drill cuttings are removed until the hole depth reaches the requirement; after the anchor hole is drilled, the air duct connected to the air compressor is placed in the hole, and it is repeatedly flushed from top to bottom and then from bottom to top to ensure that there is no debris in the hole.

5. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In the step three, the first grouting of the anchor rod is carried out by the bottom grouting method. The grouting outlet of the grouting pipe should be inserted 300-500mm from the bottom of the hole, and the slurry is continuously poured from bottom to top; the grouting pipe should be pulled out while grouting, and the pulling height should not exceed the slurry surface in the hole until the required anchor section height is reached.

6. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In the step 5, the prestress is applied in the order of starting from the anchor rod at the mid-span position of the deformation area of ​​the original waterproof board (5) to the anchor rods on the surrounding areas. The prestress is applied manually. The prestress should be applied as evenly and synchronously as possible to ensure that the deformation of the deformation area of ​​the original waterproof board (5) is completely restored to flatness.

7. A method for reinforcing water seepage deformation of basement waterproofing board according to claim 1, characterized in that: In the step 10, the polymer cement-based waterproof layer (7) is applied twice, with a total thickness of 1.0 mm and a surrounding wall height of 0.5 m.

8. A method for reinforcing water seepage deformation of a basement waterproofing board according to claim 1, characterized in that: In step 12, the fine stone concrete protective layer and leveling layer (6) is made of 40 mm thick C25 fine stone concrete material.

Images