Assembly type spiral anchor foundation with adjustable bearing capacity and design and installation method thereof

Abstract

The invention discloses a bearing capacity adjustable assembly type spiral anchor foundation and a design and installation method thereof, and the design and installation method comprises the following steps: firstly determining relevant parameters, then determining a soil body discriminant index according to the relevant parameters, and then evaluating the bearing capacity of a soil body according to the soil body discriminant index. When the spiral anchor foundation is designed, the area of the bearing platform and the number of the spiral anchors are designed according to the evaluation result, the supporting force of the spiral anchor foundation can be increased through the large area of the bearing platform and the large number of the spiral anchors, and the spiral anchor foundation is matched with a soil body with the poor bearing force; the supporting force of the spiral anchor foundation can be reduced through the small bearing platform area and the few spiral anchors, and the spiral anchor foundation is matched with a soil body with the good bearing capacity; and the spiral anchor foundation is assembled according to the design, and then the spiral anchor foundation is installed in the installation foundation pit. Therefore, the supporting force of the design can be adjusted, and the design is well matched with the application environment.

Description

Technical Field

[0001] The invention relates to a spiral anchor foundation, belonging to the technical field of foundation components, and in particular to an assembled spiral anchor foundation with adjustable bearing capacity and a design and installation method thereof. Background Art

[0002] A spiral anchor is a basic component that is embedded in the soil by rotation. Its core function is to provide stable support for various engineering structures, which can effectively reduce the amount of earth excavation, construction period and construction cost.

[0003] The Chinese patent application number is 202311477137.1, and the application date is November 7, 2023. It discloses an assembled spiral anchor foundation for river network swamp areas and its construction method. Among them, the assembled spiral anchor foundation for river network swamp areas includes a reinforced concrete structure, a spiral anchor structure, a pull-out plate, a pressure plate, a shear pile and a surrounding soil structure; the spiral anchor structure is arranged at a set position in the river network swamp area; the shear pile is arranged between the spiral anchor structures; the reinforced concrete structure includes anchor bolts, reinforced concrete main columns and reinforced concrete pedestals; the pressure plate is arranged at the bottom of the reinforced concrete pedestal; the pull-out plate is arranged on the upper part of the reinforced concrete pedestal; the reinforced concrete pedestal wraps the part of the shear pile exposed to the ground; the reinforced concrete main column is arranged above the reinforced concrete pedestal; the anchor bolts are pre-buried in the reinforced concrete main column. Although the parts of this design can be prefabricated, it still has the following defects:

[0004] In this design, the size of the pedestal is fixed, that is, the size of the supporting force that the pedestal can provide cannot be adjusted. However, when the spiral anchor device is used in areas with good soil quality, only the pedestal of the spiral anchor device is required to provide a smaller supporting force. At this time, the supporting force in this design is slightly wasted. When the spiral anchor is used in areas with poor soil quality, the pedestal of the spiral anchor device is required to provide a larger supporting force. At this time, the supporting force in this design may be insufficient, so this design is not well matched with the application environment.

[0005] The information disclosed in this background technology section is only intended to increase understanding of the overall background of the application and should not be considered as an admission or any form of suggestion that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects and problems of the prior art in that the supporting force cannot be adjusted and is not well matched with the application environment, and to provide an assembled spiral anchor foundation with adjustable supporting force, better matching with the application environment and adjustable bearing capacity, as well as a design and installation method thereof.

[0007] To achieve the above objectives, the technical solution of the present invention is:

[0008] A method for designing an assembled spiral anchor foundation with adjustable bearing capacity, the method comprising the following steps:

[0009] Step 1: First determine the water content, elastic modulus, porosity and shear strength of the soil in the installation pit of the assembled screw anchor foundation, and then calculate the soil discrimination index based on the water content, elastic modulus, porosity and shear strength;

[0010] Step 2: Evaluate the soil bearing capacity based on the soil discrimination index;

[0011] Step 3: When designing the prefabricated spiral anchor foundation, adjust the area of ​​the pedestal and the number of spiral anchors based on the soil bearing capacity evaluation results.

[0012] The calculation method of the soil discrimination index is:

[0013] S1. Normalizing the water content, elastic modulus, void ratio and shear strength in sequence to obtain normalized water content, normalized elastic modulus, normalized void ratio and normalized shear strength;

[0014] S2. assigning weights to the normalized water content, normalized elastic modulus, normalized void ratio, and normalized shear strength, and calculating the water content result, elastic modulus result, void ratio result, and shear strength result;

[0015] S3. Add the water content results, elastic modulus results, porosity results and shear strength results in sequence to obtain the soil discrimination index.

[0016] The soil bearing capacity is evaluated based on the soil discrimination index: if the soil discrimination index is greater than or equal to 0 and less than 0.5, the soil bearing capacity is poor; if the soil discrimination index is greater than or equal to 0.5 and less than 1, the soil bearing capacity is good;

[0017] The adjustment of the pedestal area and the number of spiral anchors based on the soil bearing capacity evaluation results is as follows: if the soil bearing capacity is poor, the pedestal area and the number of spiral anchors are increased when designing the prefabricated spiral anchor foundation; if the soil bearing capacity is good, the pedestal area and the number of spiral anchors are reduced when designing the prefabricated spiral anchor foundation.

[0018] An assembled spiral anchor foundation with adjustable bearing capacity, comprising a cap, a concrete column and a spiral anchor;

[0019] The cap includes a long I-beam, a first short I-beam, a second short I-beam and a plurality of prefabricated concrete blocks, one side of the middle portion of the long I-beam is vertically connected to one end of the first short I-beam, the other side of the middle portion of the long I-beam is vertically connected to the middle portion of the second short I-beam, and prefabricated concrete blocks are provided between the long I-beam and the first and second short I-beams;

[0020] The top of the precast concrete block is connected to the bottom of the upper steel plate, and the bottom of the precast concrete block is connected to the top of the lower steel plate; the top of the upper steel plate is connected to the bottom surface of the top of the long I-beam, the first short I-beam, and the second short I-beam, and the top of the long I-beam is connected to the bottom of the concrete column; the bottom of the lower steel plate is connected to the top surface of the bottom of the long I-beam, the first short I-beam, and the second short I-beam; the top of the spiral anchor is detachably connected to the bottom of the long I-beam, the bottom of the first short I-beam, or the bottom of the second short I-beam;

[0021] The prefabricated concrete block is a triangular structure, and is formed by splicing a large triangular block, a plurality of small triangular blocks and a plurality of rectangular blocks.

[0022] A plurality of the small triangular blocks and a plurality of the rectangular blocks are spliced ​​together to form a multi-layer trapezoidal block, and the multi-layer trapezoidal block and the large triangular block are spliced ​​together to form the prefabricated concrete block.

[0023] The small triangular blocks are right triangles, the trapezoidal blocks are formed by splicing small triangular blocks at both ends and a splicing rectangular block in the middle, and the splicing rectangular block is formed by splicing multiple pairs of small triangular blocks and a rectangular block.

[0024] An upper flange is provided on the top of the long I-beam, and the upper flange is connected to the lower flange at the bottom of the concrete column.

[0025] A first extension steel section is provided on a side of the first short I-beam close to the long I-beam, and one end of the first extension steel section is vertically connected to the middle portion of the long I-beam;

[0026] A second extension steel section is provided on a side of the second short I-beam close to the long I-beam, and one end of the second extension steel section is vertically connected to the middle portion of the long I-beam.

[0027] The spiral anchor includes an anchor body, the top of the anchor body is a spiral steel section, the spiral steel section is detachably connected to the bottom of the long I-beam, the first short I-beam or the second short I-beam, the outer circumference of the anchor body is evenly wrapped with spiral sheets, and the bottom of the anchor body is a conical head.

[0028] A method for installing an assembled spiral anchor foundation with adjustable bearing capacity, the method comprising the following steps:

[0029] Step 1: Dig out the installation pit, level the ground of the installation pit, and then drill the reserved holes for the screw anchors on the installation pit;

[0030] Step 2: First, screw the spiral anchors into the reserved holes in sequence, so that the top of the spiral anchors is higher than the ground, and then fix the spiral anchors; then, splice and fix the middle part of one side of the long I-beam with one end of the first short I-beam, and then splice and fix the middle part of the other side of the long I-beam with one end of the second short I-beam to obtain an I-beam frame, and then fix the I-beam frame to the lower steel plate to obtain an overall frame, and then hoist the overall frame above the spiral anchors, and then connect and fix the overall frame to the spiral anchors;

[0031] Step 3: First, use large triangular blocks, small triangular blocks and rectangular blocks to splice into multiple precast concrete blocks on the overall frame, then fix the precast concrete blocks to the overall frame in sequence, then fix the upper steel plate on the top of the precast concrete blocks, and finally fix the concrete column on the top of the long I-beam;

[0032] Step 4: Backfill the installation pit and compact the soil. At this point, the installation of the device is completed.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention provides an assembled spiral anchor foundation with adjustable bearing capacity and a design and installation method thereof, wherein the design method comprises the following steps: a first step: determining a soil discrimination index based on the water content, elastic modulus, porosity, and shear strength of the soil; a second step: evaluating the soil bearing capacity based on the soil discrimination index; and a third step: adjusting the area of ​​the cap and the number of spiral anchors based on the soil bearing capacity evaluation results when designing the assembled spiral anchor foundation. That is, when the soil bearing capacity is poor, the area of ​​the cap is increased and the number of spiral anchors is increased; when the soil bearing capacity is good, the area of ​​the cap is reduced and the number of spiral anchors is reduced. The advantages of the present invention also include:

[0035] First point: The area of ​​the cap and the number of screw anchors are set according to the bearing capacity evaluation results of the soil, so the supporting force can be adjusted;

[0036] Second point: The soil discrimination index is obtained based on the relevant parameters of the soil, and the soil discrimination index is referred to when designing the spiral anchor, so it is better matched with the application environment.

[0037] Therefore, the supporting force of the present invention can be adjusted and better matched with the application environment.

[0038] 2. In the present invention, an assembled spiral anchor foundation with adjustable bearing capacity and its design and installation method, the spiral anchor foundation includes a cap, a concrete column and a spiral anchor, the cap includes a long I-beam, a first short I-beam, a second short I-beam and a plurality of concrete prefabricated blocks, the long I-beam is vertically connected to the first short I-beam and the second short I-beam, and the three are connected with the concrete prefabricated blocks, the top and bottom of the concrete prefabricated blocks are respectively connected to the upper steel plate and the lower steel plate, the upper steel plate and the lower steel plate are respectively connected to the long I-beam, the first short I-beam and the second short I-beam, the concrete prefabricated blocks are spliced ​​by a plurality of large triangular blocks, small triangular blocks and rectangular blocks. When used, a foundation pit is first dug, and then The ground is leveled, and then the spiral anchors are driven into the reserved holes. The long I-beam, the first short I-beam, and the second short I-beam are then spliced ​​together to obtain an I-beam frame. The lower steel plate is then spliced ​​on the I-beam frame to obtain an overall frame. The overall frame is then hoisted and fixed to the spiral anchors. Large triangular blocks, small triangular blocks, and rectangular blocks are then used to splice multiple prefabricated concrete blocks. The internal gaps are filled with cement mortar to form a whole concrete block. The cement mortar is used to adapt the size of the concrete blocks to the upper and lower steel plates. The concrete prefabricated blocks are then fixed to the overall frame. The upper steel plate is then fixed, and the concrete column is fixed on the top of the upper steel plate. The advantages of the present invention also include:

[0039] First point: large triangular blocks, small triangular blocks and rectangular blocks can be spliced ​​into precast concrete blocks of various sizes. Precast concrete blocks of different sizes can provide different levels of support, so they can be matched with various application environments that require different levels of support. In addition, the number of large triangular blocks, small triangular blocks and rectangular blocks can be effectively saved, which reduces the project cost to a certain extent.

[0040] Second point: The components of the present invention are prefabricated in the factory and then assembled on site at the foundation pit. The heavy foundation is divided into a plurality of large triangular blocks, small triangular blocks and rectangular blocks of smaller weight, thus avoiding the transportation difficulties caused by muddy roads in river network and swamp areas, thereby saving transportation costs.

[0041] Therefore, the present invention has low cost and is convenient to transport.

[0042] 3. In the present invention's prefabricated spiral anchor foundation with adjustable bearing capacity and its design and installation method, an extension steel section is provided at one end of the first and second short I-beams near the long I-beam. When used, the extension steel section seamlessly connects the first and second short I-beams with the long I-beam, improving overall stability. Without the extension steel section, cement mortar would easily flow into the gap, resulting in a decrease in strength. Therefore, the present invention has higher strength.

[0043] 4. The present invention provides an assembled spiral anchor foundation with adjustable bearing capacity, and its design and installation method. The spiral anchor comprises an anchor body, a spiral steel section, a spiral blade, and a conical head. During use, the conical head facilitates the downward movement of the spiral anchor into the pre-set hole, the spiral blade provides a tighter connection between the spiral anchor and the ground, thereby increasing the vertical bearing capacity of the spiral anchor. The spiral steel section facilitates connection with the long I-beam, the first short I-beam, or the second short I-beam. Therefore, the present invention provides improved vertical bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of the design method in the present invention.

[0045] Figure 2 It is a structural schematic diagram of the spiral anchor foundation in the present invention.

[0046] Figure 3 yes Figure 2 Schematic diagram of the structure of the first short I-beam.

[0047] Figure 4 yes Figure 2 Top view of .

[0048] Figure 5 yes Figure 2 Schematic diagram of the structure of the middle and upper steel plates.

[0049] Figure 6 yes Figure 2 Schematic diagram of the structure of the middle and lower steel plates.

[0050] Figure 7 It is a schematic diagram of the structure of splicing into larger precast concrete blocks.

[0051] Figure 8 It is a schematic diagram of a structure that is spliced ​​into smaller precast concrete blocks.

[0052] Figure 9 yes Figure 2 Schematic diagram of the structure of medium and long I-beam.

[0053] Figure 10 yes Figure 2 Schematic diagram of the structure of the first short I-beam.

[0054] Figure 11 yes Figure 2 Schematic diagram of the structure of the second short I-beam.

[0055] Figure 12 yes Figure 2 Schematic diagram of the structure of the connecting steel sheet.

[0056] Figure 13 yes Figure 2 Schematic diagram of the structure of the concrete column.

[0057] Figure 14 yes Figure 2 Schematic diagram of the structure of the spiral anchor.

[0058] Figure 15 It is a schematic diagram of a smaller number of helical anchors.

[0059] Figure 16 This is a schematic diagram of a large number of spiral anchors.

[0060] In the figure: pedestal 1, long I-beam 11, long top surface 111, long bottom surface 112, first connecting hole 113, No. 1 fixing hole 114, first short I-beam 12, first short bottom surface 121, second connecting hole 122, No. 2 fixing hole 124, first extended steel section 125, upper steel plate 13, upper steel plate hole 131, lower steel plate 14, lower steel plate hole 141, second short I-beam 15, second short bottom surface 151, third connecting hole 15 2. No. 3 fixing hole 154, second extension steel section 155, concrete column 2, lower flange 21, lower flange hole 211, spiral anchor 3, anchor body 31, spiral steel section 32, spiral plate 33, conical head 34, connecting steel plate 6, upper flange 61, upper flange hole 611, flange fixing screw 612, precast concrete block 7, large triangular block 71, small triangular block 721, rectangular block 722, spliced ​​rectangular block 723, trapezoidal block 73. DETAILED DESCRIPTION

[0061] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] In one embodiment of the present application, see Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 one A design method for an assembled spiral anchor foundation with adjustable bearing capacity, the method comprising the following steps:

[0063] Step 1: First determine the water content W, elastic modulus E, porosity e and shear strength τ of the soil in the installation pit of the assembled screw anchor foundation, and then calculate the soil discrimination index SDI based on the water content W, elastic modulus E, porosity e and shear strength τ;

[0064] Step 2: Evaluate the soil bearing capacity based on the soil discrimination index SDI;

[0065] Step 3: When designing the assembled spiral anchor foundation, adjust the area of ​​the base 1 and the number of spiral anchors 3 according to the soil bearing capacity evaluation results.

[0066] Furthermore, the soil discrimination index SDI is calculated as follows:

[0067] S1. Normalize the water content W, elastic modulus E, porosity e and shear strength τ in turn to obtain the normalized water content Normalized elastic modulus Normalized porosity ratio Normalized shear strength

[0068] S2, normalized water content Normalized elastic modulus Normalized porosity ratio Normalized shear strength Assign weights and calculate the moisture content Elastic modulus results Void ratio results and shear strength results

[0069] S3, the water content results Elastic modulus results Void ratio results and shear strength results Add them up in sequence to get the soil discrimination index SDI:

[0070]

[0071] Where: is the water content result, is the elastic modulus result, is the void ratio result, is the shear strength result;

[0072] Furthermore, the soil bearing capacity is evaluated based on the soil discrimination index: if the soil discrimination index SDI is greater than or equal to 0 and less than 0.5, the soil bearing capacity is poor; if the soil discrimination index SDI is greater than or equal to 0.5 and less than 1, the soil bearing capacity is good;

[0073] The adjustment of the area of ​​the pedestal 1 and the number of spiral anchors 3 based on the soil bearing capacity evaluation result is as follows: if the soil bearing capacity is poor, the area of ​​the pedestal 1 is increased and the number of spiral anchors 3 is increased when designing the assembled spiral anchor foundation; if the soil bearing capacity is good, the area of ​​the pedestal 1 is reduced and the number of spiral anchors 3 is reduced when designing the assembled spiral anchor foundation.

[0074] Furthermore, when the water content W is high, the risk of soil liquefaction is high and the bearing capacity decreases, so the area of ​​the cap 1 needs to be increased. When the elastic modulus E is low, the soil is weak and prone to settlement, requiring additional anchoring force from the spiral anchors 3 and increasing the stiffness of the cap 1. When the void ratio e is high, the soil is loose and the shear strength is low, requiring an increase in the number of spiral anchors 3. When the shear strength τ is low, the lateral friction resistance of the spiral anchors 3 is insufficient, requiring the cap 1 to diffuse the load. Therefore, a weighted comprehensive analysis of the aforementioned four variables is performed to dynamically adjust the area of ​​the cap 1 and the number of spiral anchors 3.

[0075] Furthermore, when conducting weighted comprehensive analysis, the above four variables are first normalized. Elastic modulus E and shear strength τ are positive indicator parameters, that is, the higher the parameters, the more favorable the impact on soil quality. Water content W and porosity e are negative indicator parameters, that is, the higher the parameters, the more unfavorable the impact on soil quality. The measured values ​​of the above four variables are mapped to the range of 0-1 to eliminate dimensional differences:

[0076]

[0077] Where: is the positive indicator parameter mapping; Xi is the actual value of the parameter, Xmin is the theoretical minimum value of the parameter in the area where the installation pit is located, and Xmax is the theoretical maximum value of the parameter in the area where the installation pit is located;

[0078]

[0079] Where: is the negative indicator parameter mapping; Yi is the actual value of the parameter, Ymin is the theoretical minimum value of the parameter in the area where the installation pit is located; Ymax is the theoretical maximum value of the parameter in the area where the installation pit is located;

[0080] Furthermore, weight distribution is performed based on the sensitivity of various parameters in the river network swamp area. The water level in the swamp area fluctuates greatly. The water content W directly affects the liquefaction of the soil and the feasibility of construction. The elastic modulus E of the soil reflects the stiffness of the soil and affects the settlement control of the foundation 1. However, the swamp soil is generally soft, so the weight is slightly lower. The porosity e is directly related to the density and bearing capacity. It is the core characteristic of the swamp soil, so the weight is slightly higher. The shear strength τ of the soil determines the lateral friction resistance of the screw anchor, and its weight is equivalent to the water content. In summary, the weight ω of each parameter is distributed: the weight of the water content ω w is 0.25, the soil elastic modulus weight ω E is 0.2, the porosity weight ω e is 0.3, the soil shear strength weight ω r is 0.25;

[0081] Furthermore, the soil grade is defined according to the calculation result of the soil discrimination index SDI, and the area of ​​the cap 1 and the number of spiral anchors 3 are dynamically adjusted: if the calculated soil discrimination index SDI value is within the range of 0-0.5, it indicates that the soil quality is soft bog soil, which can be regarded as a region with poor soil quality and poor supporting capacity, and the area of ​​the cap 1 is increased and the number of spiral anchors 3 is increased; if the calculated soil discrimination index SDI value is within the range of 0.5-1.0, it indicates that the soil quality is dense peat or medium-to-high-grade bog soil, which can be regarded as a region with good soil quality and good supporting capacity, and the area of ​​the cap 1 is reduced and the number of spiral anchors 3 is appropriately reduced;

[0082] Furthermore, the specific dimensions of the assembled spiral anchor foundation with adjustable bearing capacity are designed according to the load combination of the transmission tower (including dead load, live load, wind load, earthquake load, etc.) and the bearing capacity of the foundation.

[0083] In one embodiment of the present application, see Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 , an assembled spiral anchor foundation with adjustable bearing capacity, the device includes a cap 1, a concrete column 2 and a spiral anchor 3; the cap 1 includes a long I-beam 11, a first short I-beam 12, a second short I-beam 15 and a plurality of precast concrete blocks 7, one side of the middle part of the long I-beam 11 is vertically connected to one end of the first short I-beam 12, the other side of the middle part of the long I-beam 11 is vertically connected to the middle part of the second short I-beam 15, and a precast concrete block 7 is arranged between the long I-beam 11 and the first short I-beam 12 and the second short I-beam 15; the top of the precast concrete block 7 is connected to the bottom of the upper steel plate 13, and the bottom of the precast concrete block 7 is connected to the lower steel plate 14 is connected; the top of the upper steel plate 13 is connected to the bottom surface of the top of the long I-beam 11, the first short I-beam 12, and the second short I-beam 15, and the top of the long I-beam 11 is connected to the bottom of the concrete column 2; the bottom of the lower steel plate 14 is connected to the top surface of the bottom of the long I-beam 11, the first short I-beam 12, and the second short I-beam 15; the top of the spiral anchor 3 is detachably connected to the bottom of the long I-beam 11, the bottom of the first short I-beam 12, or the bottom of the second short I-beam 15; the precast concrete block 7 is a triangular structure, and the precast concrete block 7 is spliced ​​by a large triangular block 71, a plurality of small triangular blocks 721, and a plurality of rectangular blocks 722.

[0084] A method for installing an assembled spiral anchor foundation with adjustable bearing capacity, the method comprising the following steps:

[0085] Step 1: Dig out the installation pit, level the ground of the installation pit, and then drill the reserved holes for the screw anchor 3 on the installation pit;

[0086] Step 2: First, screw the spiral anchors 3 into the reserved holes in sequence so that the tops of the spiral anchors 3 are higher than the ground, and then fix the spiral anchors 3; then, splice and fix the middle part of one side of the long I-beam 11 with one end of the first short I-beam 12, and then splice and fix the middle part of the other side of the long I-beam 11 with one end of the second short I-beam 15 to obtain an I-beam frame, and then fix the I-beam frame to the lower steel plate 14 to obtain an overall frame, and then hoist the overall frame above the spiral anchors 3, and then connect and fix the overall frame to the spiral anchors 3;

[0087] Step 3: First, use the large triangular block 71, the small triangular block 721 and the rectangular block 722 to splice into multiple precast concrete blocks 7 on the overall frame, then fix the precast concrete blocks 7 to the overall frame in sequence, then fix the upper steel plate 13 on the top of the precast concrete blocks 7, and then fix the concrete column 2 on the top of the long I-beam 11;

[0088] Step 4: Backfill the installation pit and compact the soil. At this point, the installation of the device is completed.

[0089] For further information, see Figure 6 、 Figure 7 A plurality of the small triangular blocks 721 and a plurality of the rectangular blocks 722 are spliced ​​together to form a multi-layer trapezoidal block 73 , and the multi-layer trapezoidal block 73 and the large triangular block 71 are spliced ​​together to form the prefabricated concrete block 7 .

[0090] For further information, see Figure 6 、 Figure 7 The small triangular block 721 is a right triangle, and the trapezoidal block 73 is composed of small triangular blocks 721 at both ends and a splicing rectangular block 723 in the middle. The splicing rectangular block 723 is composed of multiple pairs of small triangular blocks 721 and a rectangular block 722.

[0091] When applied, in river network swamp areas, if the soil discrimination index SDI value is within the range of 0.5-1.0, a good evaluation result of the land bearing capacity can be obtained. At this time, it can be spliced ​​into smaller prefabricated concrete blocks 7: first splice the large triangle 71, then splice multiple small triangle blocks 721 into spliced ​​rectangular blocks 723, then splice multiple spliced ​​rectangular blocks 723 and rectangular blocks 722 in the middle of the trapezoidal block 73, and then splice two small triangle blocks 721 at the two ends of the trapezoidal block 73, so that the hypotenuse of the two small triangle blocks 721 is respectively aligned with the two right angles of the large triangle 71. The edges are connected, and the oblique sides and the right-angled sides are in the same plane. Then, the trapezoidal block 73 and the large triangular block 71 are fixed to a smaller concrete prefabricated block 7 by cement mortar; if the soil discrimination index SDI value is within the range of 0-0.5, it can be obtained that the land bearing capacity is poor. At this time, it is necessary to splice them into a larger concrete prefabricated block 7: first splice them into smaller concrete prefabricated blocks 7, and then use splicing rectangular blocks 723 and rectangular blocks 722 to splice in the middle of the trapezoidal block 73, and then use two small triangular blocks 721 to splice at both ends of the trapezoidal block 73, and then the trapezoidal The upper bottom of the block 73 is connected to the hypotenuse of the smaller concrete prefabricated block 7, and the hypotenuse and the right-angled side of the small triangular block 721 are in the same plane, and then fixed to a larger concrete prefabricated block 7 by cement mortar; the large triangle 71 can be directly stuck in the connection between the long I-beam 11 and the first short I-beam 12 and the second short I-beam 15, which is convenient for on-site construction splicing, and the size of the large triangle 71 is slightly larger, so there is no need to splice too many small triangular blocks 721 and rectangular blocks 722, saving human resources. When splicing, most of the small triangular blocks 721 are the same, and the gaps are made of rectangular blocks. 722 is filled; only the large triangle 71, the small triangle block 721 and the rectangular block 722 need to be prefabricated to complete the splicing of smaller or larger concrete prefabricated blocks 7. The mold cost of the concrete prefabricated blocks 7 is low, and when making the concrete prefabricated blocks 7, the water-cement ratio can be uniformly controlled to make the concrete prefabricated blocks 7 have higher compressive strength, so that the bearing capacity of the overall foundation is higher and the construction quality is improved. In the prior art, the concrete prefabricated blocks 7 are often manufactured on-site in river network muddy areas, so it is difficult to control the water-cement ratio, resulting in low compressive strength of the concrete prefabricated blocks 7 in the prior art.

[0092] In another embodiment of the present application, see Figure 8 、 Figure 9 、 Figure 10The bottom of the long I-beam 11 is a long bottom surface 112, and a plurality of first connection holes 113 are evenly distributed on the long bottom surface 112, and the first connection holes 113 are detachably connected to the top of the spiral anchor 3; the bottom of the first short I-beam 12 is a first short bottom surface 121, and a plurality of second connection holes 122 are evenly distributed on the first short bottom surface 121, and the second connection holes 122 are detachably connected to the top of the spiral anchor 3; the bottom of the second short I-beam 15 is a second short bottom surface 151, and a plurality of third connection holes 152 are evenly distributed on the second short bottom surface 151, and the third connection holes 152 are detachably connected to the top of the spiral anchor 3.

[0093] During application, the splicing of the spiral anchor 3 can be completed according to the actual supporting force requirements. For example, when the soil bearing capacity is good, the spiral anchor 3 can be connected at intervals on the first connecting hole 113, the second connecting hole 122, and the third connecting hole 152 to achieve the effect of meeting the supporting force requirements and saving spiral anchor 3. When the soil bearing capacity is poor, the spiral anchor 3 can be connected to all the first connecting holes 113, the second connecting holes 122, and the third connecting holes 152 to achieve the effect of meeting the supporting force requirements.

[0094] In another embodiment of the present application, see Figure 9 、 Figure 12 、 Figure 13 The top of the long I-beam 11 is connected to the bottom of the connecting steel plate 6. The top of the connecting steel plate 6 is provided with an upper flange 61. The top of the upper flange 61 is connected to the bottom of the lower flange 21 at the bottom of the concrete column 2. Upper flange holes 611 are evenly distributed on the upper flange 61. Lower flange holes 211 are provided on the lower flange 21 at positions corresponding to the upper flange holes 611. Flange fixing screws 612 are inserted into the lower flange holes 211 and the upper flange holes 611.

[0095] When in use, first connect the long I-beam 11 to the connecting steel plate 6, which can be fixed by screws, then align the upper flange hole 611 with the lower flange hole 211, and then screw the flange fixing screws 612 into the upper flange hole 611 and the lower flange hole 211 in turn, thus completing the fixation of the upper flange plate 61 and the lower flange plate 21, and then completing the fixation of the long I-beam 11 and the concrete column 2.

[0096] In another embodiment of the present application, see Figure 8 、 Figure 9 、 Figure 10A first extension steel section 125 is provided on the side of the first short I-beam 12 close to the long I-beam 11, and one end of the first extension steel section 125 is vertically connected to the middle part of the long I-beam 11; a second extension steel section 155 is provided on the side of the second short I-beam 15 close to the long I-beam 11, and one end of the second extension steel section 155 is vertically connected to the middle part of the long I-beam 11.

[0097] During application, when the first short I-beam 12 is connected to the long I-beam 11, the first extended steel section 125 is connected to the middle part of the long I-beam 11 to prevent the formation of a gap between the first short I-beam 12 and the long I-beam 11, which will cause the cement mortar to flow, thereby causing the overall strength to decrease; when the second short I-beam 15 is connected to the long I-beam 11, the second extended steel section 155 is connected to the middle part of the long I-beam 11 to prevent the formation of a gap between the second short I-beam 15 and the long I-beam 11, which will cause the cement mortar to flow, thereby causing the overall strength to decrease.

[0098] In another embodiment of the present application, see Figure 4 、 Figure 5 、 Figure 6 、 Figure 9 、 Figure 10 、 Figure 11 The upper steel plate 13 has upper steel plate holes 131 evenly distributed on the edge thereof, and the upper steel plate holes 131 correspond to the No. 1 fixing hole 114 at the top of the long I-beam 11, the No. 2 fixing hole 124 at the top of the first short I-beam 12, or the No. 3 fixing hole 154 at the top of the second short I-beam 15. Fixing screws are inserted into the upper steel plate holes 131 and the No. 1 fixing hole 114, the No. 2 fixing hole 124, or the No. 3 fixing hole 154.

[0099] Furthermore, lower steel plate holes 141 are evenly distributed on the lower steel plate 14, and the lower steel plate holes 141 correspond to the threaded holes at the bottom of the long I-beam 11, the first short I-beam 12 or the second short I-beam 15, and fixing screws are inserted into the lower steel plate holes and the threaded holes.

[0100] During application, first align the upper steel plate hole 131 with the No. 1 fixing hole 114, the No. 2 fixing hole 124 or the No. 3 fixing hole 154, and then screw the fixing screws into the upper steel plate hole 131 and the No. 1 fixing hole 114, the No. 2 fixing hole 124 or the No. 3 fixing hole 154 in turn to complete the fixation of the upper steel plate 13 and the long I-beam 11, the first short I-beam 12 or the second short I-beam 15; align the lower steel plate hole 141 with the threaded holes at the bottom of the long I-beam 11, the first short I-beam 12 or the second short I-beam 15 and then screw in the fixing screws to complete the fixation of the lower steel plate 14 and the long I-beam 11, the first short I-beam 12 or the second short I-beam 15.

[0101] In another embodiment of the present application, see Figure 2 、 Figure 3 、 Figure 13 The spiral anchor 3 includes an anchor body 31, the top of the anchor body 31 is a spiral steel section 32, the spiral steel section 32 is detachably connected to the bottom of the long I-beam 11, the first short I-beam 12 or the second short I-beam 15, the outer circumference of the anchor body 31 is evenly wrapped with spiral sheets 33, and the bottom of the anchor body 31 is a conical head 34.

[0102] When in use, the conical head 34 allows the spiral anchor 3 to be easily pressed down into the reserved hole. When the spiral piece 33 is screwed into the soil, it will generate shear resistance, thereby improving the vertical bearing capacity and pull-out resistance of the spiral anchor 3. The spiral steel section 32 is provided with a thread, which is convenient for connection with the bottom of the long I-beam 11, the first short I-beam 12 or the second short I-beam 15.

[0103] In another embodiment of the present application, see Figure 2 、 Figure 3 The outer surfaces of all metal parts are coated with anti-corrosion materials, the spiral anchor 3 uses fiberglass material, and all bolts use high-strength bolts. Compared with the concrete foundation, it ensures sufficient tensile strength and avoids the risk of tensile damage to the foundation caused by settlement due to poor geology and high groundwater level in river network muddy areas.

[0104] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed in the present invention should be included in the protection scope recorded in the claims.

Claims

1. A design method for an assembled spiral anchor foundation with adjustable bearing capacity, characterized by: The method comprises the following steps: Step 1: First determine the water content, elastic modulus, porosity and shear strength of the soil in the installation pit of the assembled screw anchor foundation, and then calculate the soil discrimination index based on the water content, elastic modulus, porosity and shear strength; Step 2: Evaluate the soil bearing capacity based on the soil discrimination index; Step 3: When designing the assembled screw anchor foundation, the area of ​​the cap (1) and the number of screw anchors (3) are adjusted according to the soil bearing capacity evaluation results.

2. The design method of a prefabricated spiral anchor foundation with adjustable bearing capacity according to claim 1, characterized in that: The calculation method of the soil discrimination index is: S1. Normalizing the water content, elastic modulus, void ratio and shear strength in sequence to obtain normalized water content, normalized elastic modulus, normalized void ratio and normalized shear strength; S2. assigning weights to the normalized water content, normalized elastic modulus, normalized void ratio, and normalized shear strength, and calculating the water content result, elastic modulus result, void ratio result, and shear strength result; S3. Add the water content results, elastic modulus results, porosity results and shear strength results in sequence to obtain the soil discrimination index.

3. The design method of a prefabricated spiral anchor foundation with adjustable bearing capacity according to claim 2, characterized in that: The soil bearing capacity is evaluated based on the soil discrimination index: if the soil discrimination index is greater than or equal to 0 and less than 0.5, the soil bearing capacity is poor; if the soil discrimination index is greater than or equal to 0.5 and less than 1, the soil bearing capacity is good; The area of ​​the pedestal (1) and the number of the spiral anchors (3) are adjusted according to the soil bearing capacity evaluation result as follows: if the soil bearing capacity is poor, the area of ​​the pedestal (1) is increased and the number of the spiral anchors (3) is increased when designing the assembled spiral anchor foundation; if the soil bearing capacity is good, the area of ​​the pedestal (1) is reduced and the number of the spiral anchors (3) is reduced when designing the assembled spiral anchor foundation.

4. An assembled spiral anchor foundation with adjustable bearing capacity according to claim 1, characterized in that: The foundation comprises a cap (1), a concrete column (2) and a screw anchor (3); The pedestal (1) comprises a long I-beam (11), a first short I-beam (12), a second short I-beam (15) and a plurality of prefabricated concrete blocks (7); one side of the middle portion of the long I-beam (11) is vertically connected to one end of the first short I-beam (12); the other side of the middle portion of the long I-beam (11) is vertically connected to the middle portion of the second short I-beam (15); and a prefabricated concrete block (7) is provided between the long I-beam (11) and the first short I-beam (12) and the second short I-beam (15); The top of the concrete prefabricated block (7) is connected to the bottom of the upper steel plate (13), and the bottom of the concrete prefabricated block (7) is connected to the top of the lower steel plate (14); the top of the upper steel plate (13) is connected to the bottom surface of the top of the long I-beam (11), the first short I-beam (12), and the second short I-beam (15), and the top of the long I-beam (11) is connected to the bottom of the concrete column (2); the bottom of the lower steel plate (14) is connected to the top surface of the bottom of the long I-beam (11), the first short I-beam (12), and the second short I-beam (15); the top of the spiral anchor (3) is detachably connected to the bottom of the long I-beam (11), the bottom of the first short I-beam (12), or the bottom of the second short I-beam (15); The prefabricated concrete block (7) is a triangular structure, and is formed by splicing a large triangular block (71), a plurality of small triangular blocks (721), and a plurality of rectangular blocks (722).

5. The assembled spiral anchor foundation with adjustable bearing capacity according to claim 4, characterized in that: A plurality of the small triangular blocks (721) and a plurality of the rectangular blocks (722) are spliced ​​together to form a multi-layer trapezoidal block (73), and the multi-layer trapezoidal block (73) and the large triangular block (71) are spliced ​​together to form the prefabricated concrete block (7).

6. The assembled spiral anchor foundation with adjustable bearing capacity according to claim 5, characterized in that: The small triangular block (721) is a right triangle. The trapezoidal block (73) is formed by splicing small triangular blocks (721) at both ends and a splicing rectangular block (723) in the middle. The splicing rectangular block (723) is formed by splicing multiple pairs of small triangular blocks (721) and a rectangular block (722).

7. The assembled spiral anchor foundation with adjustable bearing capacity according to claim 4, characterized in that: An upper flange (61) is provided on the top of the long I-beam (11), and the upper flange (61) is connected to a lower flange (21) at the bottom of the concrete column (2).

8. The assembled spiral anchor foundation with adjustable bearing capacity according to claim 4, characterized in that: A first extension steel section (125) is provided on one side of the first short I-beam (12) close to the long I-beam (11), and one end of the first extension steel section (125) is vertically connected to the middle of the long I-beam (11); A second extension steel section (155) is provided on one side of the second short I-beam (15) close to the long I-beam (11), and one end of the second extension steel section (155) is vertically connected to the middle of the long I-beam (11).

9. The assembled spiral anchor foundation with adjustable bearing capacity according to claim 4, characterized in that: The spiral anchor (3) comprises an anchor body (31), the top of the anchor body (31) is a spiral steel section (32), the spiral steel section (32) is detachably connected to the bottom of the long I-beam (11), the first short I-beam (12) or the second short I-beam (15), the outer circumference of the anchor body (31) is evenly wound with spiral sheets (33), and the bottom of the anchor body (31) is a conical head (34).

10. A method for installing the assembled spiral anchor foundation with adjustable bearing capacity according to claim 4, characterized in that: The method comprises the following steps: Step 1: dig out the installation pit, level the ground of the installation pit, and then drill a reserved hole for the screw anchor (3) on the installation pit; Step 2: First, screw the spiral anchor (3) into the reserved hole in sequence so that the top of the spiral anchor (3) is higher than the ground, and then fix the spiral anchor (3); then, splice and fix the middle part of one side of the long I-beam (11) with one end of the first short I-beam (12), and then splice and fix the middle part of the other side of the long I-beam (11) with one end of the second short I-beam (15) to obtain an I-beam frame, and then fix the I-beam frame to the lower steel plate (14) to obtain an overall frame, and then hoist the overall frame above the spiral anchor (3), and then connect and fix the overall frame to the spiral anchor (3); Step 3: First, use large triangular blocks (71), small triangular blocks (721) and rectangular blocks (722) to splice into multiple concrete prefabricated blocks (7) on the overall frame, then fix the concrete prefabricated blocks (7) to the overall frame in sequence, then fix the upper steel plate (13) on the top of the concrete prefabricated blocks (7), and then fix the concrete column (2) on the top of the long I-beam (11); Step 4: Backfill the installation pit and compact the soil. At this point, the installation of the device is completed.

Images