Underwater riprap foundation bed tamping method based on sand compaction pile ship

Abstract

The invention discloses an underwater riprap foundation bed tamping method based on a sand compaction pile ship. The method comprises a sand compaction pile ship transformation process and a tamping and leveling process. When the flow of transforming the sand compaction pile ship is carried out, sand outlet guide doors at the lower ends of the three pile sinking sleeves on the sand compaction pile ship are cut off firstly; the lower ends of the three pile sinking sleeves are each connected with a bottom flange; the three tamping plate devices are connected to the bottom flanges of the three pile sinking sleeves in a one-to-one correspondence mode, and each tamping plate device comprises a tamping sinking pipe, a top flange, a tamping sinking bottom plate, an enclosure plate, a middle plate, a plurality of upper-layer stiffening plates and a plurality of lower-layer stiffening plates; when the tamping and leveling process is carried out, underwater riprap operation on the lowest layer of the foundation bed is carried out firstly, and then the transformed sand compaction pile ship is moved to a vibrating tamping position on the underwater riprap surface of the lowest layer of the foundation bed for tamping and leveling; and then the ship is moved to the next ship position for tamping and leveling of the next vibrating tamping position. The construction efficiency in the drop hammer tamping process of the underwater riprap foundation bed can be improved.

Description

Technical Field

[0001] The invention relates to a compaction method for an underwater riprap bed based on a compaction sand pile ship. Background Art

[0002] The underwater riprap base is a common base structure used in water transport engineering structures to level the underwater foundation and facilitate subsequent construction work. It is widely used in water transport engineering. The underwater riprap base is generally used to throw stones onto the mud surface by filling on the water. Due to the influence of water buoyancy and water flow during the riprap process, the thickness of the riprap is often not guaranteed to be uniform, and the stones are often in a loose accumulation state after the riprap is completed, which requires leveling and compaction to meet the construction requirements of the subsequent foundation of the building. The traditional underwater riprap base is mainly leveled by means of drop hammer compaction and blasting compaction. Among them, blasting compaction uses underwater explosives to detonate, and the impact force generated by the explosion is used to compact the riprap. However, the underwater blasting process is highly professional, and not all general construction teams can carry out the construction. At the same time, underwater blasting is easy to affect the surrounding ecological resources and is prohibited in some waters. Drop hammer compaction uses a heavy iron or concrete rammer to strike the surface of the riprap by gravity, thereby achieving the effect of leveling and compacting the riprap. It has a wider range of applications, but drop hammer compaction requires repeatedly lifting the hammer to a certain height and then relying on free fall to hammer the hammer on the surface of the riprap base bed. The entire hammer lifting process is inefficient, resulting in inefficiency of the entire construction process. At the same time, the process of lifting and dropping the hammer is easily affected by waves and water flow, resulting in a deviation between the drop hammer position and the predetermined position.

[0003] Underwater compacted sand pile is a widely used foundation reinforcement technology in the past decade. It is a special compacted sand pile ship that uses a vibrating pipe sinking equipment and a pipe cavity pressurizing device to force sand into the soft underwater foundation. After vibration pipe pulling, back driving and compaction and expansion, compacted sand piles are formed, thereby increasing the strength of the foundation and accelerating the consolidation of the foundation. It has the characteristics of short construction period, obvious reinforcement effect and good process controllability. It is particularly suitable for foundation reinforcement of offshore artificial islands, breakwaters, revetments, deep-water ports and other projects. The compacted sand pile ship is a special ship type specially suitable for compacted sand pile construction. It is generally composed of pile frame, pipe sinking vibration hammer, pile sinking casing, control room and quality monitoring system, GPS measurement and positioning system, air supply system, storage hopper, sand material conveying system, filling hopper and other key components. However, with the protection of ecological resources in recent years, the sand source cost of compacted sand piles has become increasingly high, leaving many compacted sand pile ships idle. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for compacting an underwater riprap bed based on a compaction sand pile ship, which can improve the construction efficiency of the underwater riprap bed during the drop hammer compaction process.

[0005] The object of the present invention is achieved as follows: a method for compacting an underwater riprap bed based on a compacting sand pile ship, comprising a process of transforming a compacting sand pile ship and a compacting and leveling process;

[0006] The process of transforming the compacted sand pile ship includes the following steps:

[0007] S11, cutting off the sand outlet guide gates at the lower ends of three pile casings on the sand compaction pile ship;

[0008] S12, connecting a bottom flange to each lower end of the three pile driving casings;

[0009] S13, connect three tamping plate devices to the bottom flanges of three pile driving casings one by one, each tamping plate device includes a tamping tube, a top flange, a tamping bottom plate, a protective plate, an intermediate plate, a plurality of upper stiffening plates and a plurality of lower stiffening plates; wherein the outer diameter of the tamping tube is the same as the outer diameter of the pile driving casing, and the wall thickness of the tamping tube is not less than the wall thickness of the pile driving casing; the top flange is fixed to the top of the tamping tube; the tamping bottom plate is rectangular and fixed to the lower end of the tamping tube, and the tamping bottom plate A plurality of drainage holes are evenly distributed on the top; the enclosure plate is fixed on the top surface of the edges of the ramming bottom plate; the size of the middle plate is smaller than that of the ramming bottom plate, and the middle plate is fixedly sleeved on the middle and lower part of the ramming tube; a plurality of upper stiffening plates are evenly distributed on the circumference and fixed between the outer surface of the ramming tube and the top surface of the middle plate; a plurality of lower stiffening plates are evenly distributed on the circumference and fixed on the lower outer surface of the ramming tube and fixed between the middle plate and the ramming bottom plate, and the outer end surfaces of a plurality of lower stiffening plates are fixed on the inner side surface of the enclosure plate;

[0010] The compaction and leveling process includes the following steps:

[0011] S21, firstly perform underwater riprap operation on the lowest layer of the foundation bed, then move the modified compacting sand pile ship to the vibration tamping position on the surface of the underwater riprap on the lowest layer of the foundation bed, and anchor and fix the compacting sand pile ship at the vibration tamping position;

[0012] S22, start the vibrating hammer on the top of the three pile casings of the compacting sand pile ship, so that the three pile casings and the three tamping plate devices start to vibrate, and after preheating and air vibration for a period of time, gradually lower the three pile casings, so that the tamping bottom plates of the three tamping plate devices gradually approach the surface of the underwater riprap layer, until the tamping bottom plates contact the surface of the underwater riprap layer, increase the power of the vibrating hammer, and after vibrating for a period of time, lift the three pile casings, so that the tamping bottom plates of the three tamping plate devices are separated from the underwater riprap layer, and then turn off the vibrating hammer;

[0013] S23, moving the ship to the next position to prepare for compaction and leveling at the next vibration tamping position; when moving the ship, it is necessary to ensure that there is a certain overlap area between the vibration tamping position and the previous vibration tamping position;

[0014] If the overlap length between the vibration tamping position after the ship is moved and the previous vibration tamping position in the length direction is set to L1=LS / 2, L is the length of the tamping bottom plate, S is the center distance between the three pile casings on the compacting sand pile ship, that is, S is also the distance between the center lines of the three tamping bottom plates in the length direction, then the lateral moving distance of the compacting sand pile ship is S / 2;

[0015] If the overlap length in the width direction between the vibration tamping position after the ship is moved and the previous vibration tamping position is set to L2, B is the width of the tamped bottom plate, and L2 is less than B / 2, then the longitudinal moving distance of the compaction sand pile ship is B-L2;

[0016] S24, after the compaction pile ship moves to the set position and anchors, repeat step S32 to perform compaction and leveling at the new vibration and tamping position;

[0017] S25, when the bottom layer of underwater riprap on the base bed is compacted and leveled, first carry out underwater riprap operation on the upper layer of the base bed, and then repeat steps S31 to S34 to compact and level the current layer of underwater riprap on the base bed until the compaction and leveling of the entire base bed underwater riprap is completed.

[0018] In the above-mentioned method for compacting an underwater riprap bed based on a compaction sand pile ship, when performing step S12, a plurality of stiffening plates are evenly fixed circumferentially between the top surface of the bottom flange and the outer surface of the pile casing, the plurality of stiffening plates have different heights and are staggered, and a local reinforcement plate is fixed between the top of each stiffening plate and the outer surface of the pile casing.

[0019] In the above-mentioned method for compacting an underwater riprap base bed based on a compaction sand pile ship, during step S13, a plurality of stiffening plates are evenly fixed circumferentially between the bottom surface of the top flange and the outer surface of the tamping tube, the plurality of stiffening plates have different heights and are staggered, and a local reinforcement plate is fixed between the bottom of each stiffening plate and the outer surface of the tamping tube.

[0020] In the above-mentioned method for compacting an underwater riprap bed based on a compaction sand pile ship, when performing step S13, the heights of the plurality of upper stiffening plates are different and staggered, and a local reinforcement plate is arranged between the top inner end surface of each upper stiffening plate and the outer surface of the tamping tube.

[0021] The compaction method of the underwater riprap bed based on the compaction sand pile ship of the present invention has the following characteristics:

[0022] 1. The present invention solves the shortcomings of low efficiency of existing heavy hammer tamping and the susceptibility of the falling position of the drop hammer to the influence of waves and water flow, and solves the idleness problem of existing sand pile compaction ships due to the shortage of sand sources for ecological protection.

[0023] 2. The present invention designs a tamping plate device suitable for the bottom modification of the pile casing of the compaction sand pile ship, and is matched with a corresponding connecting flange, which can quickly complete the modification of the compaction sand pile ship and the rapid disassembly and assembly of the tamping plate device, and can adapt to different vibration and tamping requirements of different underwater riprap areas by quickly replacing tamping plate devices of different sizes.

[0024] 3. A complete set of construction technology for vibrating and compacting the underwater riprap base bed using a compaction sand pile ship is proposed, and a clear relationship between the ship moving distance, the size of the rammed bottom plate, and the designed overlap length is given, which facilitates the actual construction of the construction personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an elevation view of a bottom flange or a top flange used in the method for compacting an underwater riprap bed based on a compaction sand pile ship of the present invention;

[0026] Figure 2 yes Figure 1 AA view in the figure;

[0027] Figure 3 It is an elevation view of a tamping plate device used in the tamping method of the underwater riprap bed based on a compaction sand pile ship of the present invention;

[0028] Figure 4 yes Figure 3 A top view of

[0029] Figure 5 is a perspective view of the tamping plate device;

[0030] Figure 6 It is a front view (partial) of the compacting sand pile ship after performing step S13 of the compacting method of the underwater riprap bed based on the compacting sand pile ship of the present invention;

[0031] Figure 7 is a side view of the state when performing step S22 of the compaction method of the present invention;

[0032] Figure 8 is a schematic plan view of the lateral movement distance of the compaction sand pile ship when performing step S23 of the compaction method of the present invention;

[0033] Fig. 9 It is a schematic plan view of the longitudinal movement distance of the compaction sand pile ship when performing step S23 of the compaction method of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] See also Figures 1 to 9The method for compacting an underwater riprap bed based on a compacting sand pile ship of the present invention comprises a process of transforming a compacting sand pile ship and a compacting and leveling process.

[0036] The process of transforming the compacted sand pile ship includes the following steps:

[0037] S11, cutting off the sand guide gates at the lower ends of the three pile casings 10 on the sand pile compaction ship 100;

[0038] S12, a bottom flange 11 is connected to each of the lower ends of the three pile casings 10; twelve stiffening plates 12 are evenly fixed circumferentially between the top surface of the bottom flange 11 and the outer surface of the pile casing 10, the heights of the twelve stiffening plates 12 are different and staggered, and a local reinforcement plate 30 (see Figure 1 and Figure 2 ), thereby avoiding the formation of circumferential cracks in the pile casing 10 due to welding at the same height, and reinforcing the local stress concentration area where the stiffening plate 12 is welded to the pile casing 10, thereby improving the impact load resistance and fatigue strength performance of the overall structure;

[0039] S13, connect three tamping plate devices 200 to the bottom flanges 11 of the three pile driving sleeves 10 one by one, each tamping plate device 200 includes a tamping pipe 20, a top flange 21, a tamping bottom plate 23, a protective plate 24, an intermediate plate 22, twelve upper stiffening plates 25 and twelve lower stiffening plates 26; wherein the outer diameter of the tamping pipe 20 is the same as the outer diameter of the pile driving sleeve 10, and the wall thickness of the tamping pipe 20 is not less than the wall thickness of the pile driving sleeve 10, so as to achieve a uniform transition of the pile driving sleeve 10 and the strength of the tamping pipe 20 of the tamping plate device 200 is not less than the strength of the pile driving sleeve 10; the top flange 21 is fixed to the top of the tamping pipe 20, and the bottom surface of the top flange 21 is connected to the tamping pipe 20. 0, twelve stiffening plates 12 are evenly fixed on the circumference between the outer surface of the ramming tube 20, and the heights of the twelve stiffening plates 12 are different and staggered, and a local reinforcing plate 30 is fixed between the bottom of each stiffening plate 12 and the outer surface of the ramming tube 20, thereby avoiding the formation of circumferential cracks in the ramming tube 20 due to welding at the same height, and reinforcing the local stress concentration parts where the stiffening plates 12 are welded to the ramming tube 20, so as to improve the impact load resistance and fatigue strength performance of the overall structure; the ramming bottom plate 23 is rectangular and fixed to the lower end of the ramming tube 20, and a plurality of drainage holes 230 are evenly arranged on the ramming bottom plate 23, so that water can pass through the ramming bottom plate 23 during the ramming process, reducing the ramming bottom plate in the water Vibration resistance; the shape of the tamping bottom plate 23 is determined to be rectangular mainly because the distance from the pile frame 101 of the compacting sand pile ship 100 to the bow is small, while the lateral spacing between the three sand pile casings 10 is large. Considering that after the compaction of a certain position is completed, when the compaction sand pile ship is moved to the next compaction position, a certain overlap area is required between the two compaction positions; the guard plate 24 is fixed on the top surface of the edges around the tamping bottom plate 23. The guard plate 24 can prevent the riprap from entering the tamping plate device 200 during the compaction process, increase the overall vibrating mass, and may cause local extrusion of the tamping plate device 20, endangering the safety of the structure of the tamping plate device 20; the guard plate 24 is a certain distance away from the edge of the tamping bottom plate 23, which is for To facilitate welding with the rammed bottom plate 23; the size of the middle plate 22 is smaller than the rammed bottom plate 23, and the middle plate 22 is fixed in the middle and lower part of the rammed tube 20; twelve upper stiffening plates 25 are evenly distributed around the circumference and fixed between the outer surface of the rammed tube 20 and the top surface of the middle plate 22, and the heights of the twelve upper stiffening plates 25 are different and staggered, and a local reinforcement plate 30 is arranged between the top inner end surface of each upper stiffening plate 25 and the outer surface of the rammed tube 20, thereby avoiding the formation of circumferential cracks in the rammed tube 20 due to welding at the same height, and reinforcing the local stress concentration part where the stiffening plate 12 is welded to the rammed tube 20, thereby improving the impact load resistance and fatigue strength performance of the overall structure;Twelve lower stiffening plates 26 are evenly distributed around the circumference and fixed on the lower outer surface of the rammed tube 20. The top surfaces of the twelve lower stiffening plates 26 are fixed on the bottom surface of the middle plate 22. The bottom surfaces of the twelve lower stiffening plates 26 are fixed on the top surface of the rammed bottom plate 23. The outer end surfaces of the twelve lower stiffening plates 26 are fixed on the inner side surface of the enclosure plate 24, so as to support the enclosure plate 24 (see; Figures 3 to 6 );

[0040] The compaction and leveling process includes the following steps:

[0041] S21, firstly carry out underwater riprap operation on the lowest layer of the subgrade, the thickness of the riprap should be determined according to the vibration capacity of the compacting sand pile ship and the size and gradation of the block stone particles, then move the modified compacting sand pile ship 100 to the vibration tamping position of the surface of the underwater riprap on the lowest layer of the subgrade, and anchor the compacting sand pile ship at the vibration tamping position;

[0042] S22, start the vibrating hammer 102 on the top of the three pile casings 10 of the compacting sand pile ship, so that the three pile casings 10 and the three tamping plate devices 200 start to vibrate. After preheating and air-vibrating for 30s to 45s, the three pile casings 10 are gradually lowered, so that the tamping bottom plates 23 of the three tamping plate devices 200 gradually approach the surface of the underwater riprap layer, until the tamping bottom plates 23 contact the surface of the underwater riprap layer, the power of the vibrating hammer 102 is turned up, and after vibrating for 45s to 90s, the three pile casings 10 are lifted up, so that the tamping bottom plates 23 of the three tamping plate devices 200 are separated from the underwater riprap layer, and then the vibrating hammer 102 is turned off (see Figure 7 );

[0043] S23, move the ship to the next ship position to prepare for compaction and leveling of the next vibration and tamping position; when moving the ship, ensure that there is a certain overlap area between the vibration and tamping position and the previous vibration and tamping position; due to the distance limit between the pile frame 101 and the bow, the dimension of the tamped bottom plate 23 in the length direction (transverse to the ship) is greater than the dimension in the width direction (longitudinal to the ship), which leads to a difference in stiffness in the length direction and the width direction during the vibration process, resulting in a difference in the vibration and tamping effect, so there may be a difference in the overlap length in the length direction and the overlap length in the width direction, and the specific effect can be determined based on the on-site process test results;

[0044] If the overlap length between the vibration position after the ship is moved and the previous vibration position in the length direction is set to L1=LS / 2, L is the length of the tamping bottom plate 23, S is the center distance between the three pile casings 10 on the compacting sand pile ship 100, that is, S is also the distance between the center lines of the three tamping bottom plates 23 in the length direction, then the lateral moving distance of the compacting sand pile ship 100 is S / 2 (see Figure 8 );

[0045] If the overlap length in the width direction between the vibration tamping position after the ship is moved and the previous vibration tamping position is set to L2, B is the width of the tamping bottom plate 23, and L2 is less than B / 2, then the longitudinal moving distance of the compaction sand pile ship 100 is B-L2 (see Fig. 9 );

[0046] S24, after the compaction pile ship 100 moves to the set position and anchors, step S22 is repeated to perform compaction and leveling of the new vibration and tamping position;

[0047] S25, when the bottom layer of underwater riprap on the base bed is compacted and leveled, first carry out underwater riprap operation on the upper layer of the base bed, and then repeat steps S21 to S24 to compact and level the current layer of underwater riprap on the base bed until the compaction and leveling of the entire base bed underwater riprap is completed.

[0048] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Those skilled in the relevant technical field may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the scope of the present invention and should be defined by the claims.

Claims

1. A method for compacting an underwater riprap bed based on a compacting sand pile ship, comprising a modification process of a compacting sand pile ship and a compacting and leveling process; characterized in that: The process of transforming the compacted sand pile ship includes the following steps: S11, cutting off the sand outlet guide gates at the lower ends of three pile casings on the sand compaction pile ship; S12, connecting a bottom flange to each lower end of the three pile driving casings; S13, connect three tamping plate devices to the bottom flanges of three pile driving casings one by one, each tamping plate device includes a tamping tube, a top flange, a tamping bottom plate, a protective plate, an intermediate plate, a plurality of upper stiffening plates and a plurality of lower stiffening plates; wherein the outer diameter of the tamping tube is the same as the outer diameter of the pile driving casing, and the wall thickness of the tamping tube is not less than the wall thickness of the pile driving casing; the top flange is fixed to the top of the tamping tube; the tamping bottom plate is rectangular and fixed to the lower end of the tamping tube, and the tamping bottom plate A plurality of drainage holes are evenly distributed on the top; the enclosure plate is fixed on the top surface of the edges of the ramming bottom plate; the size of the middle plate is smaller than that of the ramming bottom plate, and the middle plate is fixedly sleeved on the middle and lower part of the ramming tube; a plurality of upper stiffening plates are evenly distributed on the circumference and fixed between the outer surface of the ramming tube and the top surface of the middle plate; a plurality of lower stiffening plates are evenly distributed on the circumference and fixed on the lower outer surface of the ramming tube and fixed between the middle plate and the ramming bottom plate, and the outer end surfaces of a plurality of lower stiffening plates are fixed on the inner side surface of the enclosure plate; The compaction and leveling process includes the following steps: S21, firstly perform underwater riprap operation on the lowest layer of the foundation bed, then move the modified compacting sand pile ship to the vibration tamping position on the surface of the underwater riprap on the lowest layer of the foundation bed, and anchor and fix the compacting sand pile ship at the vibration tamping position; S22, start the vibrating hammer on the top of the three pile casings of the compacting sand pile ship, so that the three pile casings and the three tamping plate devices start to vibrate, and after preheating and air vibration for a period of time, gradually lower the three pile casings, so that the tamping bottom plates of the three tamping plate devices gradually approach the surface of the underwater riprap layer, until the tamping bottom plates contact the surface of the underwater riprap layer, increase the power of the vibrating hammer, and after vibrating for a period of time, lift the three pile casings, so that the tamping bottom plates of the three tamping plate devices are separated from the underwater riprap layer, and then turn off the vibrating hammer; S23, moving the ship to the next position to prepare for compaction and leveling at the next vibration and tamping position; when moving the ship, it is necessary to ensure that there is a certain overlap area between the vibration and tamping position and the previous vibration and tamping position; If the overlap length between the vibration tamping position after the ship is moved and the previous vibration tamping position in the length direction is set to L1=LS / 2, L is the length of the tamping bottom plate, S is the center distance between the three pile casings on the compacting sand pile ship, that is, S is also the distance between the center lines of the three tamping bottom plates in the length direction, then the lateral moving distance of the compacting sand pile ship is S / 2; If the overlap length in the width direction between the vibration tamping position after the ship is moved and the previous vibration tamping position is set to L2, B is the width of the tamped bottom plate, and L2 is less than B / 2, then the longitudinal moving distance of the compaction sand pile ship is B-L2; S24, after the compaction pile ship moves to the set position and anchors, repeat step S32 to perform compaction and leveling at the new vibration and tamping position; S25, when the bottom layer of underwater riprap on the base bed is compacted and leveled, first carry out underwater riprap operation on the upper layer of the base bed, and then repeat steps S31 to S34 to compact and level the current layer of underwater riprap on the base bed until the compaction and leveling of the entire base bed underwater riprap is completed.

2. The method for compacting an underwater riprap bed based on a compacted sand pile ship according to claim 1, characterized in that: When performing step S12, a plurality of stiffening plates are evenly fixed circumferentially between the top surface of the bottom flange and the outer surface of the pile driving casing, the plurality of stiffening plates have different heights and are staggered, and a local reinforcement plate is fixed between the top of each stiffening plate and the outer surface of the pile driving casing.

3. The method for compacting an underwater riprap bed based on a compacted sand pile ship according to claim 1, characterized in that: When performing step S13, a plurality of stiffening plates are evenly fixed circumferentially between the bottom surface of the top flange and the outer surface of the rammed tube. The plurality of stiffening plates have different heights and are staggered, and a local reinforcement plate is fixed between the bottom of each stiffening plate and the outer surface of the rammed tube.

4. The method for compacting an underwater riprap bed based on a compacted sand pile ship according to claim 1, characterized in that: When performing step S13, the heights of the plurality of upper stiffening plates are different and staggered, and a local reinforcement plate is arranged between the top inner end surface of each upper stiffening plate and the outer surface of the rammed tube.

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