Corrosion-free precast pile mechanical connection construction method

Abstract

The invention provides a corrosion-free precast pile mechanical connection construction method, which relates to the technical field of precast pile connection and comprises the steps of precast pile preparation, connecting device preparation, pile splicing operation and the like. The durability of the pile foundation can be greatly improved, the later maintenance cost is reduced, and the service life of a building is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of precast pile connection, in particular to a corrosion-free precast pile mechanical connection construction method. Background Art

[0002] During the construction of prefabricated piles, the connection parts between piles are prone to corrosion and damage due to long-term erosion by corrosive substances in groundwater and soil, which seriously affects the stability and durability of the entire pile foundation. According to relevant engineering statistics, in some coastal areas or areas with high groundwater levels and corrosive soil, about 30% of building pile foundations have corrosion problems in the connection parts to varying degrees within 10 years after construction, resulting in safety hazards such as settlement and tilting of the buildings, which not only increases a large amount of later maintenance costs, but also has a serious impact on the normal use and life of the buildings.

[0003] Precast pile mechanical connection has been widely used due to its fast construction speed. The curing agent is applied between the upper and lower pile sections. However, since the flatness of the upper and lower pile sections cannot meet the requirements during production, the curing agent cannot effectively fill the gap between the upper and lower pile sections to achieve the purpose of protecting the pile mechanical connector. Therefore, it is urgent to develop an efficient and reliable corrosion-free precast pile mechanical connection construction method. Summary of the invention

[0004] In view of the above-mentioned prior art, the present invention proposes a corrosion-free prefabricated pile mechanical connection construction method.

[0005] The present invention provides a corrosion-free prefabricated pile mechanical connection construction method, comprising the following steps: Step 1: Prefabricated pile preparation: Grind the connection end of the prefabricated pile to make its surface roughness reach Ra6.3-Ra12.5μm; Step 2: Preparation of the connection device: The connection device is provided with an upper sleeve and a lower sleeve, the insertion rod is reliably connected to the upper sleeve, an expansion water stop ring is put on the insertion rod, a plurality of balls are installed in the sleeve, the bottom of the sleeve is connected to the inner bottom of the lower sleeve through a spring, and the insertion end of the insertion rod is provided with an inclined slideway for the balls to slide and a groove matching the balls; a glass container filled with a curing agent is provided inside the lower sleeve below the balls, and the glass container is used to insert the insertion rod and is broken under the squeezing of the insertion rod; Step 3: Pile connection operation: Use lifting equipment to lift the precast pile with the upper sleeve and connect it with the precast pile with the lower sleeve that is in place.

[0006] Preferably, in step 2, the upper sleeve and the lower sleeve are both made of high-strength alloy steel, and the surface of the plug rod is galvanized, and the thickness of the galvanized layer is not less than 80 μm.

[0007] Preferably, in step 2, the diameter of the ball is 6 mm ± 0.05 mm; the groove is an annular groove, and the width of the annular groove is 6.2-6.5 mm.

[0008] Preferably, in step 2, the expansion water stop ring is a water-swellable rubber water stop ring, and the expansion rate is not less than 200%.

[0009] Preferably, in step 2, the curing agent is an epoxy resin-based curing agent, the curing time is 2-3 hours, and the compressive strength after curing is not less than 80 MPa, and the tensile strength is not less than 40 MPa.

[0010] Preferably, in step 2, the wall thickness of the glass container is 2 mm.

[0011] Preferably, in step 3, during the insertion of the insertion rod into the lower sleeve, a high-precision displacement sensor is used to monitor the insertion depth and speed of the insertion rod in real time to ensure that the insertion depth deviation is within ±5mm and the insertion speed is within the range of 0.4-0.6m / min; at the same time, stress strain gauges are installed on the insertion rod and the sleeve to monitor the change in friction between the insertion rod and the sleeve. When the friction change exceeds ±10N, the insertion operation is stopped immediately and the ball, spring and inner wall of the sleeve are checked for foreign matter or damage.

[0012] Preferably, in step 3, after the glass container is broken, the filling condition of the curing agent is randomly inspected, and at least one part is selected from every certain number of pile foundation connection parts, and the filling state of the curing agent in the gaps of each component is observed by drilling and coring to ensure that the curing agent can evenly fill the gaps between the upper sleeve, the lower sleeve, the plug rod and other components without obvious voids or unfilled gaps; and the filling height of the curing agent is checked, and the filling height of the curing agent is required to be within the design requirement of ±3 mm.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention proposes a corrosion-free precast pile mechanical connection construction method, which effectively solves the problem of easy corrosion of the precast pile connection parts. Through the unique device design and the application of curing agent, the durability of the pile foundation is greatly improved, the later maintenance cost is reduced, and the service life of the building is extended.

[0014] 2. The various components of the device of the present invention have been carefully designed and selected to ensure the tightness and stability of the connection, improve the bearing capacity of the prefabricated piles, and meet the needs of various complex geological conditions and construction projects.

[0015] 3. The construction process of the present invention is relatively simple and easy to operate. Through precise construction steps and parameter control, the construction quality and efficiency can be guaranteed, and it has good engineering application prospects; 4. The present invention avoids the problem that large-section curing agent cannot be filled due to pile body size deviation. The device and construction method of the present invention, through the precise matching of balls, springs, and plugs and sleeves, can ensure the close connection of various components and the effective filling of curing agent when there is a certain size deviation in the pile body, thereby avoiding the situation that the connection gap caused by pile body manufacturing error cannot be filled, thereby improving the reliability and stability of the connection.

[0016] 5. The present invention avoids the phenomenon of upper and lower sleeves slipping due to the structural gap of the mechanical connector itself, thereby avoiding the problem of water entering the gap and corroding the connector. After the rod is inserted into place, the ball slides into the groove, and the curing agent fills and bonds the gaps between the components, thereby effectively limiting the relative displacement between the upper and lower sleeves, preventing water leakage and corrosion caused by the structural gap, and further enhancing the durability and stability of the connector.

[0017] 6. The present invention reduces the amount of curing agent used and saves costs. Compared with the traditional method of applying curing agent over a large area, the present invention uses a glass container filled with curing agent to accurately fill the curing agent into the key gap while ensuring the anti-corrosion and sealing effect of the connection parts, thus avoiding the waste of curing agent, thereby significantly reducing the amount of curing agent used, saving material costs, and also reducing the potential impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the connecting device in an embodiment of the present invention.

[0019] Among them, 1. upper sleeve; 2. lower sleeve; 3. plug rod; 4. expansion water stop ring; 5. ball; 6. plastic set; 7. spring; 8. groove; 9. glass container. DETAILED DESCRIPTION

[0020] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0021] Embodiment: A corrosion-free prefabricated pile mechanical connection construction method, such as Figure 1 As shown, the following steps are included: Step 1: Preparation of precast piles: Grind the connection ends of the precast piles to a surface roughness of Ra6.3-Ra12.5μm (in actual projects, this roughness range can not only meet the basic requirements for surface flatness for the installation of the connection device, but also ensure construction efficiency while avoiding increased costs and weakened pile strength due to excessive grinding), and use acetone to thoroughly remove debris and oil stains on the surface of the precast piles to ensure that the surface of the precast piles is flat and clean, so as to facilitate the subsequent installation of the connection device and the tightness of the connection.

[0022] Step 2: Preparation of the connection device: The connection device is provided with an upper sleeve 1 and a lower sleeve 2. The insertion rod 3 is reliably connected to the upper sleeve 1 by a threaded mechanical connection. After the connection, a tightening torque test is performed to ensure that the connection is tight and meets the design requirements, and to ensure that the connection between the insertion rod 3 and the upper sleeve 1 is stable in subsequent operations without loosening or displacement; an expansion water stop ring 4 is put on the insertion rod 3, so that after the insertion rod 3 is inserted into the lower sleeve 2, the expansion water stop ring 4 is located between the upper and lower sleeves, which plays a good water-stopping role and prevents corrosive media such as groundwater from entering the connection part; several balls 5 are installed in the plastic sleeve 6, and the bottom of the plastic sleeve 6 is connected to the inner bottom of the lower sleeve 2 through the spring 7. The connection is carried out, and the insertion end of the rod 3 is provided with an inclined slide for the sliding of the ball and a groove 8 matching the ball 5. The position of the groove 8 corresponds to the ball 5, so that after the rod 3 is inserted into place, the ball 5 can smoothly slide into the groove 8 to ensure the quality of the pile connection, to facilitate the guidance and positioning of the rod 3 when it is inserted into the lower sleeve 2, and to ensure the tightness of the connection; a glass container 9 filled with a curing agent is arranged below the ball 5 inside the lower sleeve 2, and the glass container 9 is used to insert the rod 3 and is broken under the extrusion of the rod 3. The curing agent has good sealing, anti-corrosion and curing properties, and can quickly fill the gaps between the components after the glass container 9 is broken, forming an effective sealing and anti-corrosion layer.

[0023] Among them, the upper sleeve 1 and the lower sleeve 2 are made of high-strength alloy steel, so that they have good mechanical properties and corrosion resistance. The inner walls of the upper sleeve 1 and the lower sleeve 2 are finely processed to ensure that the matching accuracy with the plug rod 3 is within ±0.1mm to ensure the tightness and stability of the connection; one end of the plug rod 3 is mechanically connected to the upper sleeve 1 through a thread, and the thread specifications meet the relevant national standards. The connection part needs to ensure tightness and reliability. The surface of the plug rod 3 is galvanized, and the thickness of the galvanized layer is not less than 80μm to effectively enhance its corrosion resistance; the diameter of the ball 5 is 6mm (common in pile mechanical connectors on the market, this size of ball has a good balance in ensuring guidance and load-bearing capacity), and the allowable deviation is ±0.05mm (this allowable deviation range can not only meet the actual processing accuracy requirements of industrial production, but also ensure that the ball can cooperate with other components The material is stainless steel, which has good wear resistance and corrosion resistance. It is installed in the plastic set 6 for fixing the ball. The plastic set 6 is made of high-strength engineering plastic and can withstand certain pressure and impact force. The elastic coefficient of the spring is 40N / mm (after testing, this elastic coefficient can provide suitable preload and rolling flexibility with 6mm ball). When the insertion rod 3 is inserted into the lower sleeve 2, the ball 5 can roll flexibly under the action of the spring 7, and the rolling resistance does not exceed 3N (compared with the original 5N More in line with the optimized combination of ball and spring parameters, can further improve the smoothness of the insertion of the rod and the tightness of the connection); the groove 8 is an annular groove, the width of the annular groove is 6.2-6.5mm (the width is slightly larger than the ball diameter, which can not only ensure that the ball slides smoothly into the groove after the rod is inserted into place, but also play a good limiting role for the ball, preventing the ball from easily falling out of the groove when subjected to external force, thereby ensuring the stability of the connection). When the rod 3 is inserted into place, with the help of the plastic sleeve 6, the ball 5 will be squeezed and slid into the groove 8 of the rod 3, preventing the rod 3 from being pulled out of the lower sleeve 2 when the foundation floats, thereby ensuring that the quality of the pile connection meets the requirements and realizing the precise guidance and positioning of the rod 3. The expansion water stop ring 4 is a water-swellable rubber water stop ring with an expansion rate of not less than 200%. It is sleeved on the plug rod 3. After the plug rod 3 is inserted into the lower sleeve 2, the expansion water stop ring 4 is located between the upper and lower sleeves. When water seeps in, it can form an effective water stop barrier to prevent corrosive media such as groundwater from entering the connection part; the curing agent is an epoxy resin-based curing agent with a curing time of 2-3 hours. It can be rapidly cured at room temperature. The compressive strength after curing is not less than 80MPa, and the tensile strength is not less than 40MPa. Compared with other common curing agents, the curing agent used in the present invention has stronger water resistance, corrosion resistance and bonding properties with metal and rubber materials.The wall thickness of the glass container 9 is 2 mm (this wall thickness is the wall thickness of the commonly used chemical anchor glue glass container. While ensuring that the strength of the container is sufficient to withstand the extrusion during the insertion of the rod so that it can be broken at the right time, the rationality of the cost and material is also taken into consideration to avoid excessive increase in wall thickness leading to cost increases and material waste). It can withstand the extrusion during the insertion of the rod 3 and break at the right time. The curing agent should have good sealing, anti-corrosion and curing properties. After the glass container 9 is broken, it can quickly discharge the air and quickly fill the gaps between the upper sleeve 1, the lower sleeve 2, the rod 3 and other components, tightly bond the components together to form a whole, and at the same time achieve the effects of sealing, water stopping and corrosion prevention.

[0024] Step 3: Pile connection operation: Use lifting equipment to lift the prefabricated pile with the upper sleeve 1 and connect it with the prefabricated pile with the lower sleeve 2 that is already in place.

[0025] In the process of inserting the rod 3 into the lower sleeve 2, a high-precision displacement sensor is used to monitor the insertion depth and speed of the rod 3 in real time to ensure that the insertion depth deviation is within ±5mm and the insertion speed is within the range of 0.4-0.6m / min, so as to avoid damage to components caused by too fast insertion speed or too slow insertion affecting the construction efficiency and the distribution effect of the curing agent; at the same time, stress strain gauges are installed on the rod 3 and the sleeve to monitor the change of friction between the rod 3 and the sleeve. When the friction change exceeds ±10N, the insertion operation is stopped immediately, and the ball 5, spring 7 and the inner wall of the sleeve are checked for foreign matter or damage, so as to ensure the smoothness and stability of the insertion process of the rod 3 and ensure that the matching accuracy between the components is not affected; When the rod 3 is inserted into the lower sleeve 2, the interaction between the rod 3 and the internal structure of the lower sleeve 2 will squeeze the glass container 9 containing the curing agent, so that the glass container 9 breaks when the insertion depth of the rod 3 reaches a certain degree, thereby releasing the curing agent; after the glass container 9 breaks, the filling condition of the curing agent is randomly inspected, and the curing agent is checked every a certain number of pile foundation connection parts (for example, every 10 ), select at least one part, observe the filling state of the curing agent in the gaps of each component by drilling and coring, ensure that the curing agent can evenly fill the gaps between the upper sleeve 1, the lower sleeve 2, the plug rod 3 and other components, and there is no obvious void or unfilled gap; and check the filling height of the curing agent, requiring the filling height of the curing agent to reach the design requirement of ±3mm, to ensure that the curing agent can fully play the role of sealing, waterproofing and corrosion prevention, effectively bond the various components, form an integral structure, and improve the stability and durability of the pile foundation connection part; after the plug rod 3 is fully inserted into the lower sleeve 2, the ball 5 is squeezed and slid into the groove 8 of the plug rod 3 under the action of the spring 7 and the plastic sleeve 6, and the tightening force of the ball 5 on the plug rod 3 and the inner wall of the sleeve is not less than 100N, which further enhances the stability and tightness of the connection, prevents the plug rod 3 from loosening or displacement during subsequent use, especially in unfavorable conditions such as floating on the foundation, effectively prevents the plug rod 3 from being pulled out of the lower sleeve.

[0026] The above are only implementation modes of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent schemes made using the contents of the present invention specification, directly or indirectly applied in other related technical fields, are also within the patent protection scope of the present invention.

Claims

1. A corrosion-free prefabricated pile mechanical connection construction method, characterized in that: The steps include: Step 1: Prefabricated pile preparation: Grind the connection end of the prefabricated pile to make its surface roughness reach Ra6.3-Ra12.5μm; Step 2: Preparation of the connection device: The connection device is provided with an upper sleeve and a lower sleeve, the insertion rod is reliably connected to the upper sleeve, an expansion water stop ring is put on the insertion rod, a plurality of balls are installed in the sleeve, the bottom of the sleeve is connected to the inner bottom of the lower sleeve through a spring, and the insertion end of the insertion rod is provided with an inclined slideway for the balls to slide and a groove matching the balls; a glass container filled with a curing agent is provided inside the lower sleeve below the balls, and the glass container is used to insert the insertion rod and is broken under the squeezing of the insertion rod; Step 3: Pile connection operation: Use lifting equipment to lift the precast pile with the upper sleeve and connect it with the precast pile with the lower sleeve that is in place.

2. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1, characterized in that: In step 2, the upper sleeve and the lower sleeve are both made of high-strength alloy steel, and the surface of the plug rod is galvanized, and the thickness of the galvanized layer is not less than 80 μm.

3. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 2, the diameter of the ball is 6 mm ± 0.05 mm; the groove is an annular groove, and the width of the annular groove is 6.2-6.5 mm.

4. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 2, the expansion water stop ring is a water-swellable rubber water stop ring, and the expansion rate is not less than 200%.

5. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 2, the curing agent is an epoxy resin-based curing agent, the curing time is 2-3 hours, and the compressive strength after curing is not less than 80MPa, and the tensile strength is not less than 40MPa.

6. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 2, the wall thickness of the glass container is 2 mm.

7. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 3, during the insertion of the rod into the lower sleeve, a high-precision displacement sensor is used to monitor the insertion depth and speed of the rod in real time to ensure that the insertion depth deviation is within ±5mm and the insertion speed is within the range of 0.4-0.6m / min. At the same time, stress strain gauges are installed on the rod and the sleeve to monitor the change in friction between the rod and the sleeve. When the friction change exceeds ±10N, the insertion operation is stopped immediately and the ball, spring and inner wall of the sleeve are checked for foreign matter or damage.

8. The corrosion-free prefabricated pile mechanical connection construction method according to claim 1 or 2, characterized in that: In step 3, after the glass container is broken, the filling condition of the curing agent is randomly inspected. At least one part is selected from every certain number of pile foundation connection parts, and the filling condition of the curing agent in the gaps of each component is observed by drilling and coring to ensure that the curing agent can evenly fill the gaps between the upper sleeve, the lower sleeve, the plug rod and other components without obvious voids or unfilled gaps; and the filling height of the curing agent is checked, and the filling height of the curing agent is required to be within the design requirement of ±3mm.

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