Construction method for permanent and temporary combined high-pile wing wall of cast-in-place concrete support pile

Abstract

The invention provides a permanent and temporary combined high-pile wing wall construction method for a concrete pouring support pile. The construction method comprises the following steps: S1, construction preparation; s2, surveying and setting out; s3, cast-in-place pile foundation treatment; s4, pouring support pile construction; s5, high pile wing wall construction; s6, wing wall rear reinforced soil backfilling is carried out; performing layered backfilling on the interior of the empty box and behind the wall; s7, forebay earthwork construction; filling an inverted filter layer; s8, constructing a bottom plate of the forebay; arranging a PVC drainage pipe; s9, wing wall hanging plate construction; and the wing wall forms an integrally flat surface up and down in the form of pouring the concrete hanging plate. The problem that earth excavation of the deep foundation pit of the water-rich fine sand layer is difficult is solved, earth excavation of the deep foundation pit is reduced, the requirement for the bearing capacity of the foundation is met, waste caused by dismantling of the temporary supporting piles is reduced, the construction period is effectively shortened, the construction cost is saved, and safe flood prevention and control are guaranteed advantageously.

Description

Technical Field

[0001] The invention belongs to the field of water conservancy construction, and in particular relates to a construction method of a high pile wing wall combined with a permanent and temporary concrete cast-in-place support pile. Background Art

[0002] In the pump station renovation project, a 20m deep foundation pit was excavated within the planned restricted space. The geological layer was silty loam and fine sand layer with high permeability, and the foundation bearing capacity did not meet the design requirements;

[0003] If conventional construction plans are used, it is easy to cause damage to the surrounding environment; in addition, the amount of earth excavation is huge, the number of temporary support columns is also large, and the amount of work required for later demolition is also huge. Summary of the invention

[0004] In view of this, the present invention aims to propose a permanent and temporary combined high-pile wing wall construction method of concrete cast-in-place support piles, which solves the problem of difficult earth excavation in deep foundation pits in water-rich fine sand layers. It not only reduces the earth excavation of deep foundation pits and meets the requirements of foundation bearing capacity, but also reduces the waste of dismantling temporary support piles, effectively shortens the construction period and saves construction costs, which provides a favorable guarantee for safe flood prevention and control.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A method for constructing a permanent and temporary combination of concrete cast-in-place support piles and high-pile wing walls, comprising the following steps:

[0007] S1. Construction preparation;

[0008] S2, measurement and setting out;

[0009] S3. Treatment of bored pile foundation: The bored pile machine is placed in place according to the layout point, so that the base and the top are stable, and no displacement or settlement should occur during drilling and operation. The lifting pulley rim, the center of the turntable and the center of the pile hole are on the same plumb line, and the verticality is controlled to be less than 1% during the construction process;

[0010] S4, construction of cast-in-place support piles; burying casing and positioning the center line of the piles with cross-line pulling; ensuring smooth circulation of mud during construction, and continuously replacing mud during hole cleaning until pouring underwater concrete;

[0011] S5, high pile wing wall construction; excavation depth of 20m foundation pit, by setting concrete support piles for slope reinforcement support, the construction process of concrete support piles is the same as step S4;

[0012] S6. Backfill the wing wall with reinforced soil; backfill the empty box and the wall in layers;

[0013] S7, earthwork construction of forebay; filling of filter layer;

[0014] S8. Construction of the fore pool floor; arrangement of PVC drainage pipes;

[0015] S9. Wing wall hanging board construction: Cast concrete hanging boards to form an overall flat surface on the upper and lower parts of the wing wall.

[0016] Furthermore, in step S3, the mud surface in the casing is higher than the groundwater level by more than 1.0 m, and when affected by water level fluctuations, the mud surface is higher than the highest water level by more than 1.5 m;

[0017] In step S4, the mud adopts expansive soil as the wall protection. Before pouring concrete, the mud density within 500mm of the hole bottom is less than 1.25%; the sand content is not more than 8%; the colloid rate is greater than 95%; after the hole reaches the designed elevation, it is confirmed that the hole depth, hole diameter, hole wall verticality, and sediment thickness are ≤100mm, and concrete is poured after meeting the requirements.

[0018] Furthermore, in step S5, the size of the concrete support piles is φ1.5m, and the elevation of the cast-in-place piles for the foundation treatment on the water side is optimized to -1.10m. The edge of the front pool support piles is laid with a suspended bottom formwork, and the wing wall base plate and wing wall are constructed at the top of the piles according to the layout points, and the steel bars of the concrete support piles are anchored into the wing wall base plate to form a high pile wing wall.

[0019] Further, in step S5, the construction of the high pile wing wall specifically includes the following steps: first, a concrete cushion is poured according to the layout point, the steel bars are tied according to the layout, and the formwork is installed and reinforced, the wing wall bottom plate and the wing wall wall body and the buttress steel bars are tied in place at one time, the horizontal steel bars are overlapped by binding, and the vertical steel bars are overlapped by mechanical connection; bamboo plywood is used for the bottom plate side formwork, which is processed on site into the required size and then installed as a whole, and steel pipe purlins are combined with square timbers, and the formwork is reinforced firmly by using butterfly clips and tie rods to ensure the overall stability of the formwork;

[0020] The C30 concrete of the wing wall bottom plate, wing wall wall and buttress was poured in two times. When pouring the bottom plate, a pump truck was used to enter the warehouse, and the pouring was carried out in jump warehouses such as 1#, 3# on the left and 2# on the right. The pump truck covered the entire bottom plate pouring surface, and the material was laid from one end in layers and steps until the pouring of the wing wall bottom plate was completed; the wing wall hollow box wall and buttress steel bars were tied in place at one time and the concrete pouring was completed at one time; before pouring concrete, PVC material was used to set Φ150 drainage holes at a horizontal interval of 2m on the empty box wing wall; when pouring concrete, the construction was organized in the order of low position first and high position later, buttress first and wing wall later, and the material feeding speed was controlled to measure the pouring height, and the pouring thickness of each layer was 50cm.

[0021] Furthermore, in step S6, the empty box and the back of the wall are backfilled in layers, and each layer of soil is compacted to a thickness of 20 cm, and compacted with a tamping tool until the top plate of the empty box is backfilled to an elevation of 7.10 m;

[0022] Steel-plastic bidirectional geogrid is used behind the wing wall, laid perpendicular to the wall with a spacing of 0.6m. The compaction degree of the reinforced soil foundation backfill is not less than 0.95.

[0023] Furthermore, in step S7, the seepage is intercepted by the surrounding interception walls and the precipitation well of the forebay is used to ensure that the foundation pit base surface is dry; the tooth grooves are excavated on the foundation surface of the forebay near the pump room and plain concrete is poured; the slope is built from -9.37 to 3.65m at a ratio of 1:5, and the forebay foundation base is filled with medium sand, coarse sand, double-layer 60-mesh filter, melon seed slices, and gravel from bottom to top as an anti-filtration layer.

[0024] Furthermore, in step S8, after the filtration layer is laid, the processes of mounting and binding, formwork and water-stop installation and reinforcement, and pouring of concrete are carried out to complete the construction of the front pool floor, and the front plum blossom-shaped PVC drainage pipe is poured.

[0025] Furthermore, in step S9, after the wing wall concrete pouring is completed, the suspended part below the water side elevation of the concrete support pile top -1.10m will be cast into a concrete hanging plate to form an overall flat surface on the upper and lower sides of the wing wall; first, the suspended concrete support piles and concrete are roughened; then, L-shaped steel bars are implanted on the exposed concrete support piles, and the distribution steel bars are tied in the horizontal and vertical directions, and the formwork is reinforced with butterfly clips and tie rods, and finally the concrete hanging plate construction is completed.

[0026] Compared with the prior art, the method for constructing a permanent and temporary concrete cast-in-place support pile combined with a high-pile wing wall according to the present invention has the following advantages:

[0027] (1) The present invention discloses a method for constructing high-pile wing walls by combining permanent and temporary concrete support piles. By combining permanent and temporary concrete support piles, the problem of limited excavation space for deep foundation pits of wing walls and difficulty in excavating deep foundation pits in water-rich layers is solved, thereby reducing the amount of earth excavation in deep foundation pits and ensuring the safety and stability of foundation pits.

[0028] (2) The present invention provides a method for constructing a high-pile wing wall by combining permanent and temporary concrete support piles. By combining permanent and temporary concrete support piles, temporary support piles are used as foundation treatment piles, which reduces the waste of temporary support piles and meets the foundation bearing capacity requirements. The steel-plastic bidirectional geogrid is backfilled in layers behind the wall, and the compaction degree of the reinforced soil foundation backfill soil is not less than 0.95, which prevents uneven settlement of the backfill soil and soil landslides.

[0029] (3) The present invention provides a method for constructing a permanent and temporary high-pile wing wall by pouring concrete support piles. The temporary support piles are used as foundation treatment piles, which reduces the excavation depth of the foundation pit. The high-pile wing wall is formed by hanging the top of the pile, and the construction joints of the exposed support piles at the bottom are treated. The reinforced concrete scraper is poured, and the overall surface of the wing wall is ensured to be flat. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0031] Figure 1 This is a schematic cross-sectional view of a high pile wing wall of a forebay according to an embodiment of the present invention;

[0032] Figure 2 It is a schematic plan view of the fore pool wing wall according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. φ1.5m concrete support piles; 2. φ1.2m concrete cast-in-place piles; 3. Concrete cushion layer; 4. Wing wall bottom plate; 5. Wing wall body; 6. Wing wall empty box body; 7. Empty box connecting hole; 8. Empty box drainage hole; 9. Filter layer; 10. Steel-plastic bidirectional geogrid; 11. Empty box exhaust hole; 12. Empty box water inlet hole; 13. Concrete hanging board; 14. Platform in front of wing wall hanging board; 15. Old wing wall. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0036] In the description of the present invention, 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 invention 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 present invention. In addition, the terms "first", "second", and the like are only used 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", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0037] In the description of the present invention, 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 the present invention can be understood by specific circumstances.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] Relying on the forebay wing wall project of the Fenghuangjing Pump Station renovation project of the Yangtze River to Huaihe River Diversion Project (Yinjiang to Jichao), in order to improve the bearing capacity of the wing wall and the wing wall empty box foundation, bored piles of the same length of φ1.2m are adopted, and the soft foundation below the bottom plate is treated according to the slope ratio of 1:4. In order to prevent the foundation pit from damaging the surrounding environment, it is necessary to adopt concrete support piles to consolidate the surrounding soil slopes for protection. By optimizing the construction plan, a combination of permanent and temporary measures is adopted. Without affecting the stability of the foundation, the first row of foundation treatment piles facing the water are optimized to φ1.5m concrete support piles 1, and the pile top elevation is -1.10m. In order to ensure that the wing wall construction is completed before the flood season, so as to reduce the earth excavation volume of the foundation pit and the amount of temporary support piles to be broken, the bottom plate of the wing wall is suspended on the concrete support piles through a combination of permanent and temporary measures, and the high-pile wing wall construction is completed through the processes of layout, steel bar installation, formwork installation, concrete pouring, backfilling of reinforced soil on the back of the wall, and reinforced concrete hanging plate 13.

[0040] Specifically, a method for constructing a permanent concrete cast-in-place support pile combined with a high pile wing wall is provided, such as Figure 1 Figure 2 As shown, the following steps are included:

[0041] S1. Construction preparation;

[0042] S2, measurement and setting out;

[0043] S3. Treatment of bored pile foundation; the bored pile machinery is placed according to the layout point, so that the base and the top are stable, and there should be no displacement or settlement during drilling and operation, so that the lifting pulley edge, the center of the turntable and the center of the pile hole should be on the same plumb line, and the verticality can be controlled to be less than 1% during the construction process to meet the design requirements. The casing is buried and the cross-line is used to locate the center line of the pile; during the process, the mud circulation should be ensured to be smooth, and the mud surface in the casing should be more than 1.0m higher than the groundwater level. When affected by the fluctuation of the water level, the mud surface should be more than 1.5m higher than the highest water level.

[0044] S4. Construction of cast-in-place support piles; bury casing and use cross-line to locate the center line of the piles; ensure smooth circulation of mud during construction, and continuously replace mud during hole cleaning until underwater concrete is poured; use expansive soil as the mud wall protection, and before pouring concrete, the mud density within 500mm of the bottom of the hole is less than 1.25%; the sand content is not more than 8%; the colloid rate is greater than 95%; after the hole reaches the designed elevation, confirm that the hole depth, hole diameter, hole wall verticality, and sediment thickness are ≤100mm, and pour concrete after meeting the requirements.

[0045] S5, high pile wing wall construction; excavation depth of 20m foundation pit, by setting concrete support piles for slope reinforcement support, the construction process of concrete support piles is the same as step S4;

[0046] The size of the concrete support pile is φ1.5m, and the elevation of the cast-in-place piles for foundation treatment on the water side is optimized to -1.10m. The edge of the front pool support pile is paved with a suspended bottom formwork, and the wing wall bottom plate 4 and the wing wall are constructed at the top of the pile according to the layout point, and the steel bars of the concrete support pile are anchored into the wing wall bottom plate 4 to form a high pile wing wall.

[0047] The construction of high-pile wing wall specifically includes the following steps: first, pour the concrete cushion layer 3 according to the layout point, tie the steel bars according to the layout, and reinforce the formwork. The wing wall bottom plate 4 and the wing wall wall body 5 are tied in place with the buttress steel bars at one time. The horizontal steel bars are overlapped by binding, and the vertical steel bars are overlapped by mechanical connection. Bamboo plywood is used for the side form of the bottom plate, which is processed on site into the required size and then installed as a whole. Steel pipe purlins are combined with square wood. The formwork is reinforced by using butterfly clips and tie rods to ensure the overall stability of the formwork.

[0048] The C30 concrete of the wing wall bottom plate 4, wing wall wall 5 and buttress is poured in two times. When pouring the bottom plate, a pump truck is used to enter the warehouse, and the left side 1#, 3#, right side 2# and other jump warehouses are poured. The pump truck covers the entire bottom plate pouring surface, and the material is laid from one end in layers and steps until the pouring of the wing wall bottom plate 4 is completed; the wing wall empty box wall and buttress steel bars are tied in place at one time and the concrete pouring is completed at one time; before pouring concrete, the empty box wing wall is made of PVC material with Φ150 empty box drainage holes 8 set at a horizontal interval of 2m; when pouring concrete, the construction is organized in the order of low position first and high position later, buttress first and wing wall later, and the material feeding speed is controlled to measure the pouring height, and the pouring thickness of each layer is 50cm.

[0049] S6, backfill with reinforced soil behind the wing wall; backfill after the wing wall concrete meets the design strength, backfill in layers inside the empty box and behind the wall; backfill in layers inside the empty box and behind the wall, compact each layer of soil to a thickness of 20cm, and use a tamping tool to tamp until backfilling to the empty box top plate elevation of 7.10m;

[0050] A steel-plastic bidirectional geogrid 10 is used behind the wing wall, with a spacing of 0.6m and laid perpendicular to the wall surface. The compaction degree of the reinforced soil foundation backfill is not less than 0.95.

[0051] S7, earthwork construction of the forebay; fill the anti-filter layer 9; ensure the dry environment of the foundation pit surface by intercepting the seepage through the surrounding interception walls and the precipitation of the forebay precipitation well; excavate the tooth grooves on the foundation surface of the forebay near the pump room and cast plain concrete; build the slope from -9.37 to 3.65m at a ratio of 1:5, and fill the forebay foundation base from bottom to top with medium sand, coarse sand, double-layer 60-mesh filter, melon seed slices, and crushed stone as the anti-filter layer 9;

[0052] S8, construction of the front pool floor; after the filtration layer 9 is laid, the front pool floor construction is completed by carrying out processes such as installation and binding, formwork and water-stop installation and reinforcement, and pouring of concrete, and pouring of the front plum blossom-shaped PVC drainage pipe.

[0053] S9, wing wall hanging plate construction; after the wing wall concrete pouring is completed, the suspended part below the water side elevation of the concrete support pile top -1.10m will be cast into the form of concrete hanging plate 13 to form an overall flat surface on the upper and lower sides of the wing wall; first, the suspended part of the concrete support pile and the concrete are roughened; then, L-shaped steel bars are implanted on the exposed concrete support piles, and the distribution steel bars are tied in the horizontal and vertical directions, and the formwork is reinforced with butterfly clips and tie rods, and finally the construction of pouring concrete hanging plate 13 is completed.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a permanent and temporary combination of concrete cast-in-place support piles and high pile wing walls, characterized in that: The following steps are involved: S1. Construction preparation; S2, measurement and setting out; S3. Treatment of bored pile foundation: The bored pile machine is placed in place according to the layout point, so that the base and the top are stable, and no displacement or settlement should occur during drilling and operation. The lifting pulley rim, the center of the turntable and the center of the pile hole are on the same plumb line, and the verticality is controlled to be less than 1% during the construction process; S4, construction of cast-in-place support piles; burying casing and positioning the center line of the piles with cross-line pulling; ensuring smooth circulation of mud during construction, and continuously replacing mud during hole cleaning until pouring underwater concrete; S5, high pile wing wall construction; excavation depth of 20m foundation pit, by setting concrete support piles for slope reinforcement support, the construction process of concrete support piles is the same as step S4; S6. Backfill the wing wall with reinforced soil; backfill the empty box and the wall in layers; S7, earthwork construction of forebay; filling of filter layer; S8. Construction of the fore pool floor; arrangement of PVC drainage pipes; S9. Wing wall hanging board construction: Cast concrete hanging boards to form an overall flat surface on the upper and lower parts of the wing wall.

2. A method for constructing a permanent and temporary high pile wing wall with concrete cast-in-place support piles according to claim 1, characterized in that: In step S3, the mud surface in the casing is higher than the groundwater level by more than 1.0 m. When affected by the water level fluctuation, the mud surface is higher than the highest water level by more than 1.5 m. In step S4, the mud adopts expansive soil as the wall protection. Before pouring concrete, the mud density within 500mm of the hole bottom is less than 1.25%; the sand content is not more than 8%; the colloid rate is greater than 95%; after the hole reaches the designed elevation, it is confirmed that the hole depth, hole diameter, hole wall verticality, and sediment thickness are ≤100mm, and concrete is poured after meeting the requirements.

3. The method for constructing a permanent and temporary high pile wing wall with concrete cast-in-place support piles according to claim 1 is characterized in that: In step S5, the size of the concrete support pile is φ1.5m, and the elevation of the cast-in-place piles for the foundation treatment on the water side is optimized to -1.10m. The edge of the front pool support pile is paved with a suspended bottom formwork, and the wing wall bottom plate and wing wall are constructed at the top of the pile according to the layout point, and the steel bars of the concrete support pile are anchored into the wing wall bottom plate to form a high pile wing wall.

4. The method for constructing a permanent and temporary high pile wing wall combined with concrete cast-in-place supporting piles according to claim 3 is characterized in that: In step S5, the construction of the high-pile wing wall specifically includes the following steps: first, pouring a concrete cushion layer according to the layout point, tying the steel bars according to the layout, and reinforcing the template. The wing wall bottom plate and the wing wall body are tied in place with the buttress steel bars at one time. The horizontal steel bars are overlapped by tying, and the vertical steel bars are overlapped by mechanical connection; bamboo plywood is used for the bottom plate side formwork, which is processed on site into the required size and then installed as a whole, and steel pipe purlins are combined with square timbers. The template is reinforced firmly by using butterfly clips and tie rods to ensure the overall stability of the template; The C30 concrete of the wing wall base plate, wing wall wall body and buttress was poured in two times. When pouring the wing wall base plate, a pump truck was used to enter the warehouse, and the pouring was carried out in jump warehouses such as 1#, 3# on the left and 2# on the right. The pump truck covered the entire pouring surface of the wing wall base plate, and the material was laid from one end in layers and steps until the pouring of the wing wall base plate was completed; the wing wall hollow box wall and buttress steel bars were tied in place at one time and the concrete pouring was completed at one time; before pouring concrete, PVC material was used to set Φ150 drainage holes at a horizontal interval of 2m on the hollow box wing wall; when pouring concrete, the construction was organized in the order of low position first and high position later, buttress first and wing wall later, and the material feeding speed was controlled to measure the pouring height, and the pouring thickness of each layer was 50cm.

5. The method for constructing a permanent and temporary high pile wing wall combined with concrete cast-in-place supporting piles according to claim 1 is characterized in that: In step S6, the empty box and the back of the wall are backfilled in layers, and each layer of soil is compacted to a thickness of 20 cm, and compacted with a tamping tool until the top plate of the empty box is backfilled to an elevation of 7.10 m; Steel-plastic bidirectional geogrid is used behind the wing wall, laid perpendicular to the wall with a spacing of 0.6m. The compaction degree of the reinforced soil foundation backfill is not less than 0.

95.

6. The method for constructing a permanent and temporary high pile wing wall with concrete cast-in-place support piles according to claim 1 is characterized in that: In step S7, the seepage is intercepted by the surrounding interception walls and the precipitation well of the forebay is used to ensure that the foundation pit base surface environment is dry; the tooth groove is excavated on the foundation surface of the forebay near the pump room and plain concrete is poured; the slope is built from -9.37 to 3.65m at a ratio of 1:5, and the forebay foundation base is filled with medium sand, coarse sand, double-layer 60-mesh filter, melon seed slices, and crushed stone from bottom to top as an anti-filtration layer.

7. The method for constructing a permanent and temporary high pile wing wall with concrete cast-in-place support piles according to claim 1 is characterized in that: In step S8, after the filtration layer is laid, the processes of installation and binding, formwork and water-stop installation and reinforcement, and concrete pouring are carried out to complete the construction of the front pool bottom plate, and the front plum blossom-shaped PVC drainage pipe is poured.

8. The method for constructing a permanent and temporary high pile wing wall combined with concrete cast-in-place supporting piles according to claim 1 is characterized in that: In step S9, after the wing wall concrete pouring is completed, the suspended part below the water side elevation of the concrete support pile top -1.10m will be cast into a concrete hanging plate to form an overall flat surface on the upper and lower sides of the wing wall; first, the suspended concrete support piles and concrete are roughened; then, L-shaped steel bars are implanted on the exposed concrete support piles, and the distribution steel bars are tied in the horizontal and vertical directions, and the formwork is reinforced with butterfly clips and tie rods, and finally the concrete hanging plate construction is completed.

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