Construction method for pile sinking near underground diaphragm wall of sheet-pile wharf
By adopting construction methods such as lead holes, pile sinking and pile connection near the underground continuous wall of the sheet pile wharf, the problem of PHC pipe piles being difficult to implement in the wall-connected area of the construction site has been solved, the soil extrusion effect is optimized, and the structure is improved Stability and construction convenience reduce engineering costs.
Patent Information
- Application Number
- CN202411208377.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2024-12-27
AI Technical Summary
In the prior art, the construction of PHC pipe piles is difficult to implement in the completed wall-connected area, and the static pressure sinking piles have high requirements for geological conditions, which can easily cause soil extrusion and structural deviation, increasing the cost of the project.
A construction method near the underground continuous wall of the sheet pile dock is adopted, including determining the lead parameters, lead construction, pile sinking, pile connecting and pile delivery steps, and controlling the verticality and plane displacement through a long screw drilling rig and a guide rod hammer. Optimize the depth of the lead hole to reduce the soil extrusion effect, and use welding pile joint method and pile feeder to ensure pile foundation stability.
Effectively prevent soil squeezing effect during pile sinking, improve the overall stability of the front wall, reduce project cost, improve construction convenience, and ensure pile foundation bearing capacity and structural stability.
Smart Images
Figure CN119195195A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of construction technology, and in particular relates to a construction method for sinking piles near an underground continuous wall of a sheet pile wharf. Background Art
[0002] In the construction of sheet pile wharf, underground continuous wall structure is often used for the main structure of the lower part of the front wall, and the foundation of the wharf crane track beam mostly adopts prestressed concrete pipe pile structure.
[0003] If there is a pipe pile foundation rail beam near the front wall of the sheet pile wharf, usually the pipe pile sinking foundation construction is carried out first, and then the ground-connected wall construction is carried out. For the ground-connected wall that has been constructed, if the construction unit requires the use of the new pile foundation, it is usually advisable to adopt the cast-in-place pile foundation to avoid affecting the constructed structure; if the pipe pile foundation is adopted, static pressure pile sinking and other technologies are preferred.
[0004] For newly added pile foundations, cast-in-place piles are used for construction, which has a great impact on on-site environmental protection and civilized construction, and the cost of cast-in-place pile foundations is significantly higher than that of PHC (prestressed high-strength concrete) pipe piles. For newly added pile foundations, PHC pipe piles are used for construction, and static pressure piles are used. Due to the heavy weight of the static pressure equipment, higher requirements are placed on the geological conditions of the site, and static pressure piles can still produce a certain soil squeezing effect, which will still cause the existing ground-connected wall structure to deviate. Summary of the invention
[0005] The technical problem to be solved by the present invention is: to solve the problem in the prior art that PHC pipe pile construction is difficult to implement in an area where a ground continuous wall has been constructed, thereby providing a construction method for pile sinking near an underground continuous wall of a sheet pile wharf.
[0006] The technical solution adopted by the present invention to solve the technical problem is: A construction method for sinking piles near an underground continuous wall of a sheet pile wharf, wherein the bottom elevation of the underground continuous wall is H1, comprises the following steps: Determine the hole guide parameters: determine the hole guide parameters according to the specifications of the PHC piles to be used and the plate-shaped wharf structure; the hole guide diameter is smaller than the PHC pile diameter, the hole guide depth is H2, H2>H1; wherein H2 and H1 are both negative numbers; Drilling hole construction: Use a long screw drill to carry out the construction, select the drill bit according to the diameter of the PHC pile, and carry out the drilling hole construction according to the determined drilling hole parameters; Pile driving: insert the PHC piles described in the first section into the guide holes, control the verticality and plane displacement of the PHC piles within a preset range, and use a guide rod hammer for hammering construction; Pile connection: align the completed PHC pipe piles of the first section and the PHC pipe piles of the second section vertically and straighten them, and weld and fix the PHC pipe piles of the second section and the PHC pipe piles of the first section by welding; continue to press the piles after the welded part cools down naturally; Pile delivery: The pile delivery depth is determined according to the designed pile top elevation and the original ground elevation, and the PHC pipe pile is delivered to the designed elevation using a pile driver.
[0007] Preferably, the construction method for pile driving near the underground continuous wall of a sheet pile wharf of the present invention further performs slope measurement before the pile driving step: an inclinometer tube is pre-buried on the top of the underground continuous wall that has been constructed, the inclinometer tube is fixed to the underground continuous wall, and an inclinometer is placed in the inclinometer tube to measure the horizontal displacement at various depths.
[0008] Preferably, in the construction method of pile driving near the underground continuous wall of the sheet pile wharf of the present invention, the slope measurement comprises: firstly, in a direction perpendicular to the underground continuous wall and aligned with the position of the PHC pile to be driven, marking the center of the underground continuous wall in the thickness direction, then drilling a hole at the marked position to a certain depth below the top of the underground continuous wall, burying the inclinometer tube into the predetermined depth in the drill hole, and filling the periphery of the inclinometer tube; After the inclinometer tube is fixed, rinse the tube with clean water, put the inclinometer into the tube, collect initial data, and after the inclinometer is lowered to the bottom of the tube, measure after the probe is close to the temperature inside the tube. Each monitoring direction should be measured twice, forward and reverse.
[0009] Preferably, in the construction method for pile driving near the underground continuous wall of the sheet pile wharf of the present invention, displacement monitoring is also performed after the pile delivery step: the inclinometer is placed in the inclinometer tube, and data after the pile delivery is completed is collected. After the inclinometer is lowered into the bottom of the inclinometer tube, the probe is measured after it approaches the temperature inside the tube, and each monitoring direction should be measured twice, forward and reverse; The collected data after pile delivery is completed is compared with the initial data to analyze the construction effect.
[0010] Preferably, in the construction method for pile driving near the underground continuous wall of a sheet pile wharf of the present invention, in the step of determining the guide hole parameters, the guide hole diameter is 4 cm to 6 cm smaller than the diameter of the PHC pipe pile, and H2=40%H1~60%H1.
[0011] Preferably, the construction method of pile driving near the underground continuous wall of the sheet pile wharf of the present invention, when the construction method is carried out in multiple days or multiple phases, pile position control is also carried out: the pile positions are placed according to the construction drawings, red line points and axis control points are made, the pile positions are fixed with steel bars, and the pile positions to be constructed are rechecked before each day or each phase of construction and marked with lime powder.
[0012] Preferably, in the construction method for pile driving near the underground continuous wall of a sheet pile wharf of the present invention, the hole construction step comprises: during the drilling process, an intermittent drilling method is used.
[0013] Preferably, in the construction method for driving piles near the underground continuous wall of a sheet pile wharf of the present invention, in the hole-guiding construction step, the drilling speed is controlled at 1 m / min to 1.50 m / min.
[0014] Preferably, in the construction method for pile driving near the underground continuous wall of a sheet pile wharf of the present invention, in the pile driving step, after the PHC pipe pile described in the first section is inserted into the guide hole, the guide rod hammer is used to press the pile in by its own weight or the throttle is closed and the hammer is hit low to ensure the verticality and plane displacement of the PHC pipe pile described in the first section are accurate.
[0015] Preferably, in the construction method for sinking piles near the underground continuous wall of a sheet pile wharf of the present invention, in the pile connection step, two welders weld symmetrically and simultaneously, and before the PHC pipe piles described in the second section are butt-jointed with the PHC pipe piles described in the first section, the surface of the end plate to be welded is cleaned with a wire brush, and the groove is brushed until a metallic luster is exposed; when the gap at the pile end is large, it is filled with an iron sheet, and then welding is performed; when welding the piles, first spot weld 4 to 6 points symmetrically on the circumference of the groove, and after the upper and lower pile sections are fixed, welding is performed in three layers.
[0016] Preferably, in the construction method for driving piles near the underground continuous wall of a sheet pile wharf of the present invention, in the pile delivery step, the pile delivery depth is marked in advance on the pile delivery device according to the measured local ground elevation, and the PHC pipe piles are delivered to the designed elevation through tracking and observation by a level instrument on site.
[0017] The beneficial effects of the present invention are as follows: the boring pile sinking process prevents the front wall from being displaced toward the sea due to the soil squeezing effect during pile sinking, and at the same time, by optimizing the boring depth, the outer displacement of the upper half of the front wall caused by the soil squeezing effect is reduced, the soil pressure on the land side of the lower half of the front wall is increased, and the overall stability of the front wall is improved, which plays a two-way optimization role. There is no obvious loss in the bearing capacity of the pile foundation, which improves the convenience of construction and greatly reduces the engineering cost of changing to other pile foundation structures. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The technical solution of the present application is further described below in conjunction with the accompanying drawings and embodiments.
[0019] Figure 1 This is a schematic flow chart of the steps of the construction method for sinking piles near the underground continuous wall of a sheet pile wharf according to Example 1 of the present application; Figure 2 It is a schematic diagram of the construction structure of pile sinking near the underground continuous wall of the sheet pile wharf in Example 1 of the present application; Figure 3 This is a schematic diagram of the construction effect of pile sinking near the underground continuous wall of the sheet pile wharf in Example 1 of the present application; Figure 4 It is a schematic diagram of the configuration structure of the inclinometer casing of Example 1 of the present application; Figure 5 This is a schematic flow chart of the steps of the construction method for sinking piles near the underground continuous wall of a sheet pile wharf according to Example 2 of the present application; Figure 6 This is a schematic diagram of slope measurement data before and after the construction of piles near the underground continuous wall of the sheet pile wharf in Example 2 of the present application; Figure 7 This is a summary table of high-strain dynamic test results after construction of piles near the underground continuous wall of the sheet pile wharf in Example 2 of the present application.
[0020] The reference numerals in the figure are: 1. Underground continuous wall, 2. PHC piles, 3. Inclinometer tube, 4. Cast-in-place breast wall, 5. Steel tie rods, 6. Anchor wall structure, 7. Guide hole, 8. Soil squeezing effect elimination area, 9. Soil squeezing effect utilization area. DETAILED DESCRIPTION
[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.
[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.
[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.
[0024] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. Example
[0025] like Figure 1 , Figure 2 As shown, a sheet pile wharf structure, the lower part of the front wall is designed as an underground continuous wall 1, and the upper part is designed as a cast-in-place breast wall 4. The underground continuous wall 1 has been completed, and its bottom elevation is H1. The underground continuous wall 1 is connected to the anchor wall structure 6 through a steel tie rod 5. This embodiment provides a construction method for sinking piles near the underground continuous wall of a sheet pile wharf, including the following steps: Determine the parameters of the lead hole: determine the parameters of the lead hole according to the specifications of the PHC pile 2 to be used and the plate-like wharf structure; the diameter of the lead hole is smaller than the diameter of the PHC pile 2, the depth of the lead hole 7 is H2, H2>H1; wherein H2 and H1 are both negative numbers; Drilling hole construction: Use a long screw drill to construct, select a drill bit according to the diameter of the PHC pile 2, and construct the drilling hole 7 according to the determined drilling hole parameters; Pile sinking: insert the PHC pile 2 described in the first section into the guide hole, control the verticality and plane displacement of the PHC pile 2 within a preset range, and use a guide rod hammer to perform hammering construction; Pile connection: align the completed PHC pipe pile 2 of the first section with the PHC pipe pile 2 of the second section vertically, and weld and fix the PHC pipe pile 2 of the second section with the PHC pipe pile 2 of the first section by welding; continue to press the pile after the welded part cools down naturally; Pile delivery: The pile delivery depth is determined according to the designed pile top elevation and the original ground elevation, and the PHC pipe pile 2 is delivered to the designed elevation using a pile delivery device.
[0026] like Figure 2 As shown, the design elevation of the bottom of the PHC pile 2 is H3, H3<H2. It can be understood that when the pile delivery is completed, the land is above H2, which weakens the soil squeezing effect. Figure 3 As shown, the land forms a soil squeezing effect elimination area 8 above H2, and forms a soil squeezing effect utilization area 9 above H1 and below H2.
[0027] The construction method of pile sinking near the underground continuous wall of the sheet pile wharf of this embodiment can prevent the front wall from displacing toward the sea due to the soil squeezing effect during pile sinking, and at the same time, by optimizing the lead hole depth, reduce the outer displacement of the upper half of the front wall caused by the soil squeezing effect, increase the soil pressure on the land side of the lower half of the front wall, and improve the overall stability of the front wall, playing a two-way optimization role. There is no obvious loss of pile foundation bearing capacity, which improves the convenience of construction and greatly reduces the engineering cost of changing to other pile foundation structures.
[0028] In an optional embodiment, the construction method of pile driving near the underground continuous wall of the sheet pile wharf of this embodiment further performs slope measurement before the pile driving step: Figure 4 As shown, an inclinometer tube 3 is pre-buried on the top of the underground continuous wall 1 that has been constructed, the inclinometer tube 3 is fixed to the underground continuous wall 1, and an inclinometer is placed in the inclinometer tube 3 to measure the horizontal displacement at each depth. In this embodiment, the inclinometer tube 3 and the inclinometer can be used to easily obtain the slope data of the underground continuous wall 1 before and after construction, so as to determine and quantify the construction effect.
[0029] In an optional embodiment, the slope measurement includes: first, along a direction perpendicular to the underground continuous wall 1 and aligned with the position of the PHC pile 2 to be sunk, mark the center of the underground continuous wall 1 in the thickness direction, then drill a hole at the marked position to a certain depth below the top of the underground continuous wall 1, bury the inclinometer tube 3 in the drill hole to a predetermined depth, and fill the periphery of the inclinometer tube 3; after the inclinometer tube 3 is fixed, rinse the inclinometer tube 3 with clean water, put the inclinometer into the inclinometer tube 3, collect initial data, and after the inclinometer is lowered to the bottom of the inclinometer tube, measure it after the probe is close to the temperature inside the tube, and each monitoring direction should be measured twice, forward and reverse.
[0030] In an optional embodiment, after the pile delivery step, displacement monitoring is also performed: the inclinometer is placed in the inclinometer tube 3, and the data after the pile delivery is completed is collected. After the inclinometer is lowered into the bottom of the inclinometer tube, the probe is close to the temperature inside the tube before measurement. Each monitoring direction should be measured twice, positive and reverse; the collected data after the pile delivery is completed is compared with the initial data to analyze the construction effect. In this embodiment, displacement monitoring is performed after the pile delivery step, and the measured initial data can be compared for data analysis to quantify the construction effect.
[0031] In an optional embodiment, in the step of determining the guide hole parameters, the guide hole diameter is 4 cm to 6 cm smaller than the diameter of the PHC pile 2, preferably 5 cm; H2 = 40% H1 to 60% H1. In an optional embodiment, Figure 2 As shown, in this embodiment, H1 is set to -24.5m, H2 is set to -12m, and H3 is set to -37.6m. The actual construction effect of this parameter selection is good.
[0032] In an optional embodiment, when the construction method is carried out in multiple days or phases, pile position control is also performed: the pile position is placed according to the construction drawing, the red line points and axis control points are made, the pile position is fixed with steel bars, and the pile position to be constructed is rechecked before each day or each phase of construction, and marked with lime powder. In this embodiment, in the case of a long construction period, pile position control is performed, and iconic marks such as steel bars or lime powder are used so that construction can be carried out accurately during the next construction.
[0033] In an optional embodiment, the hole construction step includes: during the drilling process, an intermittent drilling method is used, that is, drilling-drilling-drilling, which is conducive to clearing the cut soil out of the ground and strengthening the loosening of deep soil.
[0034] In an optional embodiment, in the hole-guiding construction step, the drilling speed is controlled at 1 m / min to 1.50 m / min, so that if the drill is stuck, the drill rig shakes or deviates during the drilling process, the drilling can be stopped in time to find out the cause, and corrective measures can be taken before continuing the drilling.
[0035] In an optional embodiment, in the pile sinking step, after the PHC pile 2 described in the first section is inserted into the guide hole 7, the guide rod hammer is used to press in by its own weight or the throttle is closed and the hammer is hit low, so as to ensure the verticality and plane displacement of the PHC pile 2 described in the first section. The verticality and plane displacement accuracy of the PHC pile 2 described in the first section have a significant impact on the construction. In this embodiment, in order to ensure the verticality and plane displacement accuracy of the PHC pile 2 described in the first section, the guide rod hammer is used to press in by its own weight or the throttle is closed and the hammer is hit low, so as to effectively avoid the deviation of the force applied to the PHC pile 2.
[0036] In an optional embodiment, in the pile connection step, two welders weld symmetrically and simultaneously. Before the second section of the PHC pipe pile 2 is connected to the first section of the PHC pipe pile 2, the surface of the end plate to be welded is cleaned with a wire brush, and the groove is brushed until the metallic luster is exposed; when the gap between the pile ends is large, it is filled with iron sheets and then welded; when welding the piles, 4 to 6 points are first spot welded symmetrically on the circumference of the groove, and after the upper and lower pile sections are fixed, welding is performed in three layers. In this embodiment, the parallelism of the end faces of the upper and lower pile sections is strictly controlled during the pile connection, which is conducive to ensuring the overall straightness after the pile connection.
[0037] In an optional embodiment, in the pile delivery step, the pile delivery depth is marked in advance on the pile delivery device according to the measured local ground elevation, and the PHC pile 2 is delivered to the designed elevation by tracking and observing with a level meter on site. In this embodiment, by marking the pile delivery depth in advance, the PHC pile 2 can be delivered to the designed elevation more accurately. Example
[0038] This embodiment provides a construction method for sinking piles near the underground continuous wall of a sheet pile wharf, such as Figure 5 As shown, the specific construction steps are: (1) Determine the hole parameters ① Determine the diameter of lead hole 7 The diameter of the lead hole 7 directly affects the soil squeezing pressure and the bearing capacity of the pile body during the hammer pile driving. If the diameter is too small, the soil squeezing effect cannot be effectively reduced, which may easily cause the squeezing and displacement of the existing construction structure. If the diameter is too large, the friction of the pile body will be affected, which will reduce the bearing capacity of the pile body, affect the pile foundation structure, and easily cause the pile to slip during the pile driving process of the lead hole section, causing safety hazards. In this embodiment, the lead hole diameter is determined to be 5 cm smaller than the diameter of the PHC pipe pile 2. The specifications of the PHC pipe pile 2 are φ600 mm and the wall thickness is 130 mm (B-type pile). The diameter of the lead hole 7 is 550 mm. The actual measurement effectively solves the above problems.
[0039] ②Determine the depth of the lead hole The plate-shaped wharf structure of this project has an underground continuous wall 1 as the lower part of the front wall, and a cast-in-place breast wall 4 as the upper part. The bottom elevation of the underground continuous wall 1 is -24.45m, the top elevation of the cast-in-place breast wall 4 is +5.3m, the elevation of the steel tie rod 5 is +0.7m, and the dredging design elevation at the front of the wharf is -7m. The boring pile driving process prevents the seaward displacement of the front wall due to the soil squeezing effect during pile driving. At the same time, by optimizing the boring depth, the outer displacement of the upper half of the front wall caused by the soil squeezing effect is reduced, the soil pressure on the land side of the lower half of the front wall is increased, and the overall stability of the front wall is improved. At the same time, it will cause a slight displacement of the upper half of the front wall to the land side to a certain extent. In this embodiment, the boring 7 depth is to the design elevation -12.0m. Figure 2 As shown in FIG. 1 , the depth of the lead hole is about half of the depth of the steel tie rod 5 to the bottom of the front wall. This lead hole depth not only eliminates the soil squeezing effect of the upper part, but also makes full use of the soil squeezing effect of the lower part, playing a two-way optimization role. Figure 2 , Figure 3 As shown, the land forms a soil squeezing effect elimination area 8 above H2, and forms a soil squeezing effect utilization area 9 above H1 and below H2.
[0040] (2) Slope measurement The inclinometer tube 3 is pre-buried on the top of the completed underground continuous wall 1. The horizontal displacement at each depth is observed by the inclinometer to reflect the displacement change of the structure. The surveying personnel first mark the position of the PHC pile 2 to be driven vertically to the wall of the underground continuous wall 1, and then drill a hole to a depth of 1m below the top of the underground continuous wall 1. The staff of the inspection unit buries the inclinometer tube 3 in the drill hole. When the inclinometer tube 3 is drilled to the predetermined depth, a cavity is generally formed around the tube, and the outer periphery of the inclinometer tube 3 needs to be filled, such as Figure 4 As shown. After the inclinometer tube is fixed, rinse the inclinometer tube 3 with clean water, put the probe model (borer) into the inclinometer tube 3, and slide it up and down along the guide groove to check whether the guide groove is unobstructed and whether the roller slides out of the guide groove. After the inclinometer tube 3 is laid out, collect initial data. The inclinometer should be lowered into the bottom of the inclinometer tube for 5min to 10min, and then measure after the probe is close to the temperature inside the tube. Each monitoring direction should be measured twice in the forward and reverse directions.
[0041] (3) Pile position control Place the piles according to the construction drawings, and make red line points and axis control points. Use steel bars to determine the pile positions and lime powder to mark them. Before daily construction, recheck the piles to be constructed and mark them with lime powder to facilitate smooth construction.
[0042] (4) Drilling hole construction ① The long screw drilling rig is in place, and the drill bit is selected according to the diameter of PHC pile 2. The diameter of the hole is 5 cm smaller than the diameter of the pile. The bottom elevation of the hole is -12 m (the bottom elevation of the underground continuous wall 1 is -24.45 m, the bottom elevation of the front dredging is -7 m, and the front wall tie rod elevation is +0.7 m). The depth of the guide hole is about half of the height of the front wall.
[0043] ② During the drilling process, an intermittent drilling method should be adopted, namely: drilling-drilling-drilling, which is conducive to clearing the cut soil out of the ground and strengthening the loosening of deep soil.
[0044] ③During the process of drilling the lead hole, the drilling speed should be slow. The normal drilling speed can be controlled at 1m / min~1.50m / min. During the drilling process, if the drill is stuck, the drill rig shakes, or deviates, the drilling should be stopped to find out the cause and take corrective measures before continuing drilling.
[0045] (5) Pile driving The pile driving is carried out by hammering with conventional technology of guide rod hammer. The hammer is selected reasonably, heavy hammer is used to hit lightly, and the height of hammer jump is controlled within the design range. When the first section of pile is inserted, the verticality and plane displacement must be strictly controlled, and the impact energy of pile hammer must be strictly controlled within the range of hole introduction. When the pile is just inserted, the hammer body should be pressed in by itself by its own weight or the throttle should be closed and the hammer should be hit low to ensure the verticality and plane displacement of the first section of pile are accurate.
[0046] Pile sinking should be carried out continuously, and hammering should not be stopped in the middle to avoid difficulty in sinking after another hammering. If hammering must be stopped, the stopping time should be shortened as much as possible. Elastic pads can be installed between the pile hammer, alternate driving, pile driver and pile, and the pile hammer, alternate driving, pile driver and pile body should be kept on the same axis.
[0047] (6) Pile connection The welding method is used to connect piles. When connecting piles, the upper and lower piles should be aligned and straight. Two welders should weld symmetrically at the same time to reduce welding deformation. Before the piles are connected, the surfaces of the upper and lower end plates should be cleaned with a wire brush, and the groove should be brushed until the metallic luster is exposed. When the gap between the pile ends is large, it can be filled with iron sheets before welding. When welding piles, it is advisable to first spot weld 4 to 6 points symmetrically on the circumference of the groove, and then weld in three layers after the upper and lower pile sections are fixed. The pile can be pressed only after the welded pile joints have cooled naturally. The natural cooling time should not be less than 8 minutes. It is strictly forbidden to use water cooling or to press immediately after welding.
[0048] (7) Delivery of piles The pile driving depth is determined according to the designed pile top elevation and the original ground elevation. The external dimensions of the pile driver selected for pile driving should match the external dimensions of the pile to be driven, and it should have sufficient strength and rigidity. When driving the pile, the axis of the pile driver should coincide with the pile body. The pile driving depth should be marked in advance on the pile driver according to the measured local ground elevation, and the PHC pipe pile 2 should be accurately driven to the designed elevation through tracking observation with a level meter on site.
[0049] (8) Displacement monitoring After the drilling and pile driving are completed, the staff of the inspection unit will conduct deep displacement observation of the underground continuous wall. The inclinometer should be lowered into the bottom of the inclinometer tube for 5 to 10 minutes, and the measurement should be carried out after the probe is close to the temperature inside the tube. Each monitoring direction should be measured twice, forward and reverse. The data before and after the pile driving should be compared. Figure 6 As shown, according to the data comparison results, after the construction of the bored piles is completed, the top of the underground continuous wall is offset 0.38 mm toward the land perpendicular to the direction of the underground continuous wall 1, and is offset 0.72 mm to the west parallel to the direction of the underground continuous wall 1. It can be seen that the construction method of this embodiment solves the soil squeezing effect very well.
[0050] (9) High strain dynamic detection After the pile sinking is completed, the piles are subjected to high strain dynamic testing in accordance with the Technical Specifications for Testing and Monitoring of Foundations of Water Transport Engineering (JTS237-2017) and the Technical Specifications for Testing and Monitoring of Piles of Water Transport Engineering (JTS240-2020). The test results are as follows: Figure 7 As shown, the results show that the bearing capacity of the pile body meets the design requirements and the lateral resistance is not significantly reduced.
[0051] Based on the above ideal embodiments of this application, the relevant staff can make various changes and modifications without departing from the technical concept of this application through the above description. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A construction method for pile sinking near an underground continuous wall of a sheet pile wharf, wherein the bottom elevation of the underground continuous wall is H1, characterized in that: The following steps are involved: Determine the hole guide parameters: determine the hole guide parameters according to the specifications of the PHC piles to be used and the plate-shaped wharf structure; the hole guide diameter is smaller than the PHC pile diameter, the hole guide depth is H2, H2>H1; wherein H2 and H1 are both negative numbers; Drilling hole construction: Use a long screw drill to carry out the construction, select the drill bit according to the diameter of the PHC pile, and carry out the drilling hole construction according to the determined drilling hole parameters; Pile driving: insert the PHC piles described in the first section into the guide holes, control the verticality and plane displacement of the PHC piles within a preset range, and use a guide rod hammer for hammering construction; Pile connection: align the completed PHC pipe piles of the first section and the PHC pipe piles of the second section vertically, and weld and fix the PHC pipe piles of the second section and the PHC pipe piles of the first section by welding; Continue to press the pile after the welded part cools down naturally; Pile delivery: The pile delivery depth is determined according to the designed pile top elevation and the original ground elevation, and the PHC pipe pile is delivered to the designed elevation using a pile driver.
2. The construction method for pile sinking near the underground continuous wall of a sheet pile wharf according to claim 1, characterized in that: Before the pile driving step, the slope measurement is also carried out: an inclinometer tube is pre-buried on the top of the completed underground continuous wall, the inclinometer tube is fixed to the underground continuous wall, and an inclinometer is placed in the inclinometer tube to measure the horizontal displacement at each depth.
3. The construction method for pile sinking near the underground continuous wall of a sheet pile wharf according to claim 2, characterized in that: The slope measurement includes: first, in a direction perpendicular to the underground continuous wall and aligned with the position of the PHC pile to be sunk, marking the center of the underground continuous wall in the thickness direction, then drilling a hole at the marked position to a certain depth below the top of the underground continuous wall, burying the inclinometer tube in the drill hole to a predetermined depth, and filling the periphery of the inclinometer tube; After the inclinometer tube is fixed, rinse the tube with clean water, put the inclinometer into the tube, collect initial data, and after the inclinometer is lowered to the bottom of the tube, measure after the probe is close to the temperature inside the tube. Each monitoring direction should be measured twice, forward and reverse.
4. The construction method for pile sinking near the underground continuous wall of a sheet pile wharf according to claim 3 is characterized in that: After the pile delivery step, displacement monitoring is also performed: the inclinometer is placed in the inclinometer tube, and data after the pile delivery is completed is collected. After the inclinometer is lowered into the bottom of the inclinometer tube, the probe is close to the temperature inside the tube before measurement. Each monitoring direction should be measured twice, forward and reverse; The collected data after pile delivery is completed is compared with the initial data to analyze the construction effect.
5. The method for pile driving near the underground continuous wall of a sheet pile wharf according to any one of claims 1 to 4, characterized in that: In the step of determining the hole guide parameters, the hole guide diameter is 4 cm to 6 cm smaller than the diameter of the PHC pile, and H2 = 40% H1 to 60% H1.
6. The method for constructing piles near the underground continuous wall of a sheet pile wharf according to any one of claims 1 to 4, characterized in that: When the construction method is carried out over several days or phases, pile position control is also performed: pile positions are placed according to the construction drawings, red line points and axis control points are made, pile positions are fixed with steel bars, and the pile positions to be constructed are rechecked before each day or each phase of construction and marked with lime powder.
7. The method for constructing piles near the underground continuous wall of a sheet pile wharf according to any one of claims 1 to 4, characterized in that: The hole construction steps include: during the drilling process, an intermittent drilling method is adopted.
8. The construction method for sinking piles near the underground continuous wall of a sheet pile wharf according to claim 7, characterized in that: In the hole construction step, the drilling speed is controlled at 1 m / min to 1.50 m / min.
9. The method for constructing piles near the underground continuous wall of a sheet pile wharf according to any one of claims 1 to 4, characterized in that: In the pile sinking step, after the PHC pile described in the first section is inserted into the guide hole, the guide rod hammer is used to press it in by its own weight or the throttle is closed and the hammer is hit low to ensure the verticality and plane displacement of the PHC pile described in the first section are accurate.
10. The method for pile sinking near the underground continuous wall of a sheet pile wharf according to any one of claims 1 to 4, characterized in that: In the pile connection step, two welders weld symmetrically and simultaneously. Before the second section of the PHC pipe pile is connected to the first section of the PHC pipe pile, the surface of the end plate to be welded is cleaned with a wire brush, and the groove is brushed until the metallic luster is exposed; when the gap at the pile end is large, it is filled with iron sheets and then welded; when welding the piles, first spot weld 4 to 6 points symmetrically on the circumference of the groove, and after the upper and lower pile sections are fixed, weld in three layers.