Fabricated railway security wall construction method for soft soil texture

Abstract

The invention discloses a construction method of a fabricated railway security wall for soft soil, which belongs to the technical field of security wall construction, and comprises the following steps: step 1, foundation positioning, referring to a figure 1 and a figure 2, adopting a theodolite to determine the position and the elevation of the wall according to the coordinates and the elevation of the wall in a drawing in foundation pit excavation, the method comprises the following steps: carrying out the contrastive analysis by combining the position and the elevation of an existing side slope on site, adopting a stepped foundation according to the ground elevation, carrying out foundation section size arrangement according to the length of 1400mm and the width of 800mm according to the load of an upper part structure vertical to a horizontal plane, setting the foundation height to be 300mm in order to ensure the punching resistance of the foundation, and setting the foundation height to be 300mm in order to ensure the bending resistance of the foundation. The upper layer and the lower layer of the foundation are longitudinally provided with 10-at-170 reinforcing steel bars, the diameter of the reinforcing steel bars is 10 mm, and the interval is 170 mm. In this way, compared with a traditional foundation treatment method, the construction period is shorter, the ground hardening degree is improved, and the method is suitable for soft soil surface layers with different horizontal plane heights.

Description

Technical Field

[0001] The invention relates to the technical field of security fence construction, in particular to a method for constructing an assembled railway security fence for soft soil. Background Art

[0002] There are various methods for constructing wall foundations. Brick foundations have low bearing capacity and are not suitable when the geology is complex and the seismic requirements are high. The pedestal foundation requires detailed survey, has high geological requirements and poor adaptability. The pier foundation is difficult to construct when encountering groundwater and is prone to collapse. Strict quality requirements affect the progress. Concrete foundations have strong bearing capacity and are suitable for high walls and complex geology. They are seismic resistant and have good environmental adaptability. Security wall structures have their own advantages and disadvantages. Bamboo and wood walls have poor stability and are easy to decay. Brick walls are closed, unsightly and unsafe. Metal walls are expensive and require rust prevention. Glass walls have poor privacy and are unsafe. Stone walls are expensive and difficult to construct. Ecological walls have high maintenance costs. Concrete walls are mature in technology, durable, firm and safe. Brick walls are used for coastal soft soil. The wall height is 2.7m and the total length is 7.1km. The wall foundation adopts a 1.3m deep and full-length concrete strip foundation. This approach is costly and prone to uneven ground settlement, causing wall cracks, affecting the later use effect.

[0003] The Chinese patent with publication number CN114382338A proposes an assembled fence and a construction method. The assembled fence includes: an independent foundation, a groove is provided on the top, and two groove walls opposite to the groove are provided with a first bayonet with a top opening, four vertically arranged first metal embedded parts are embedded in the independent foundation, the upper ends of the first metal embedded parts extend into the groove, and the parts of the four first metal embedded parts extending into the groove are enclosed to form a second bayonet; a ground beam, an end of which is inserted into the first bayonet, and a second metal embedded part with an end extending from the end face of the ground beam is embedded in the ground beam, the part of the second metal embedded part extending from the end face of the ground beam is interlaced with the part of the first metal embedded part extending into the groove, and the height of the first bayonet is greater than the height of the ground beam; a column, which is a metal structure, and the lower end of the column is inserted into the second bayonet; an iron fence, the side of which is connected to the column.

[0004] However, the technical solution of this patent has the following problems:

[0005] This patent cannot be carried out quickly in soft soil and cannot be applied to soft soil surface layers of different horizontal surface heights.

[0006] Based on this, the present invention designs a construction method of an assembled railway security fence for soft soil to solve the above problems. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for constructing an assembled railway security fence for soft soil.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for constructing an assembled railway security fence for soft soil, comprising the following steps:

[0010] Step 1: Basic positioning, please refer to the attached Figure 1 and attached Figure 2 , the excavation of the foundation pit uses a theodolite to determine the location and elevation of the fence according to the fence coordinates and elevation in the drawings, and makes a comparative analysis based on the location and elevation of the existing slope on site. The foundation adopts a stepped foundation according to the ground elevation. The foundation is arranged with a cross-section size of 1400mm long and 800mm wide according to the load of the upper structure perpendicular to the horizontal plane. In addition, in order to ensure the anti-punching performance of the foundation, the foundation height is set to 300mm. In order to ensure the bending performance of the foundation, 10@170 steel bars are arranged longitudinally in the upper and lower layers of the foundation, with a steel bar diameter of 10mm and a spacing of 170mm. 10@150 steel bars are arranged transversely in the upper and lower layers of the foundation, with a steel bar diameter of 10mm and a steel bar spacing of 150mm.

[0011] Step 2: Excavation of foundation pit, please refer to the attached Figure 3 The foundation pit is excavated by slope, and the slope ratio and working surface width are controlled according to the design requirements, that is, the slope ratio is 1:0.5, the working surface width is 300mm, and the excavation depth is at least 900mm. In addition, a calculation formula for the excavation volume for soft soil is proposed;

[0012] Step 2.1: When foundation excavation does not require slope, the following formula can be used to calculate the excavation volume:

[0013] V 挖 =L×(B+2C)×H

[0014] Where: V 挖 : indicates excavation volume (cubic meters); L: indicates excavation length (meters); B: indicates foundation width (meters); C: indicates working surface width (meters), which is usually increased to ensure normal operation of workers; H: indicates excavation depth (meters), which is generally based on the designed outdoor floor elevation;

[0015] Step 2.2: When foundation excavation requires slope reduction, the width of the slope reduction is calculated based on the slope reduction coefficient K, i.e. KH. At this time, the following formula can be used to calculate the excavation volume:

[0016] V 挖 =L×(B+2C+KH)×H

[0017] Alternatively, for the case of rectangular pit grading, a more detailed formula can be used:

[0018] V 挖=(a+2c+KH)×(b+2c+KH)×H+1 / 3K2H 3

[0019] Where: a, b: represent the length and width of the rectangular pit respectively (meters); c: represents half of the width of the working surface (meters); K: represents the slope coefficient, which is determined according to the soil type; H: represents the excavation depth (meters);

[0020] Step 2.3, the slope coefficient K is determined according to the soil type. Generally speaking, the slope coefficient of Class I and Class II soil is 0.5, Class III soil is 0.33, and Class IV soil is 0.25. These coefficients are determined based on the physical and mechanical properties of the soil and the stability requirements of the excavation project;

[0021] Step 3: pouring cushion layer concrete. After excavation, compact the base to ensure that the foundation bearing capacity and compaction coefficient meet the use requirements. After compaction, pour the concrete cushion layer. The cushion layer concrete adopts C15 and the thickness must be at least 10cm, that is, the foundation bearing capacity ≥100kPa and the compaction coefficient ≥0.94;

[0022] Step 4: Foundation construction, please refer to the attached Figure 2 The foundation is tied according to the design drawings. The length of the lower and upper bent anchors of the short column reinforcement must meet the calculation requirements (the bent anchor refers to the anchor after the reinforcement is bent, that is, the end of the reinforcement is bent, generally made into a right-angle hook), that is, the lower bent anchor length of the short column reinforcement is 300mm, the upper bent anchor length is 100mm, and the diameter of the short column reinforcement is 10mm. Among them, the calculation formulas for the lower and upper bent anchor lengths are as follows:

[0023] Step 4.1, calculation formula for lower bend anchor length:

[0024] For the lower bent anchor, its length usually needs to be calculated based on factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The general formula can be expressed as:

[0025] Lower bend anchor length = steel bar diameter × bend anchor multiple

[0026] Among them, the bending anchor multiple is a coefficient that combines many factors, which depends on the seismic level, steel bar diameter, concrete strength, etc.

[0027] Step 4.2: Calculation formula for upper bend anchor length:

[0028] The calculation of the length of the upper bend anchor is similar to that of the lower bend anchor. It is also necessary to consider factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The calculation formula can be expressed as:

[0029] Upper bend anchor length = steel bar diameter × bend anchor multiple + beam height - protective layer thickness

[0030] Among them, beam height refers to the height from the bottom of the beam to the top of the beam, and the thickness of the protective layer refers to the distance from the steel bar to the concrete surface;

[0031] Step 5: The foundation and short columns are poured in two times. After the foundation concrete is poured, the embedded parts are installed, and then the short column concrete is poured. After the foundation concrete is poured, it is covered with geotextile and continuously watered for 3 days before backfilling;

[0032] Step 6: Installation of fence columns. Transport the fence columns and wall panels prefabricated in the processing plant to the site. Select a suitable crane according to the weight of the fence columns and wall panels, and use the "one-point lifting method" for lifting construction. During installation, the base steel plate of the fence column and the short column steel plate are fully welded. The weld width should meet the calculation requirements. After the weld is cooled, use waterproof mortar to seal and protect the weld and steel plate;

[0033] Step 7: Wall panel installation, please refer to the attached Figure 4 After the installation of the wall columns on both sides is completed, the wall panels are hoisted between the wall columns and clamped, and the gaps are sealed with mortar. The wall panel hoisting construction uses commercially available finished hoisting fixtures;

[0034] Step 8: Spreading water construction, please refer to the attached Figure 5 The wall water diversion is cast with concrete of certain thickness and strength, and the outer side is 600mm away from the wall panel. After the concrete is cast, it needs to be covered with film and watered to prevent the diversion from cracking. The diversion thickness is 100mm. The diversion cuts an expansion joint every 8m, with a width of 10mm and a depth of 30mm. After cutting, the joint is filled with asphalt paste.

[0035] Step 9: Surface coating construction: dark grey inorganic waterproof coating is used for the surface of wall columns and wall caps, and white inorganic waterproof coating is used for the surface of wall panels. In addition, the concrete surface slurry needs to be polished before painting to ensure that the concrete surface is smooth and tidy. Waterproof putty needs to be used to level the local areas, gaps, depressions, and pits. Three coats of waterproof coating are used for painting;

[0036] Step 10: Special position processing, please refer to the attached Figure 6 and attached Figure 7 ;

[0037] 1. Because the fence is bent, the fence posts and wall panels at the bend need to be processed separately. Please refer to the attached Figure 6 When the fence is bent into an obtuse angle structure, the fence posts remain unchanged, one of the wall panels is bent at one end close to the fence post, and then installed on the fence post normally; please refer to the attached Figure 7 When the fence is bent into a right-angle structure, two fence posts are installed at the right-angle position, and the two wall panels at the right-angle position are installed on one of the fence posts respectively;

[0038] 2. For wall panel treatment at height difference locations, please refer to the attached Figure 8, the foundation remains unchanged, cut the lower side of the fence panel along the height difference, cut at the lower position to form a bulge, and then install the fence panel normally on the fence column.

[0039] In addition, a test method for the wind bearing performance of precast concrete assembled enclosures is provided, wherein the test is carried out according to the following two schemes:

[0040] Option 1: Release the deadweight in stages, then place sandbags in stages. Fig. 9 , Attachment Fig.10 , Attachment Fig.11 and attached Fig.12 ;

[0041] Considering that when the wall panel is placed horizontally, the deadweight of the wall panel itself is not conducive to the stress of the wall panel. Therefore, the form of graded release of support constraints is adopted to change the mid-span deflection (the mid-span deflection refers to the distance between the highest point on both sides of the centerline of the cross-section curve and the centerline) to achieve graded changes in the mid-span bending moment (the mid-span bending moment refers to the bending moment at the midpoint of the span of the beam or part of the beam), and then achieve graded loading of deadweight. First, the support is released under the deadweight condition, aiming to gradually convert the deadweight of the concrete itself into wind load. After all the mid-span supports under the deadweight condition are released, 20kg sandbags are placed in stages until the specimen is destroyed to explore its maximum limit bearing performance.

[0042] This scheme reduces the number of lower supports to increase the spacing between supports and to increase the mid-span curved rectangular shape, thus achieving graded application of wind loads, namely:

[0043] 1) Calculation: M = αql2 = 0.107ql2, four-span continuous beam;

[0044] 2) Calculation: M = αql2 = 0.116ql2, three-span continuous beam;

[0045] 3) Calculation: M = αql2 = 0.125ql2, single-span continuous beam, where the α coefficient is determined according to the specific support spacing.

[0046] It is easy to see that when the support spacing changes, the maximum mid-span bending moment changes accordingly, which is equivalent to the release of the deadweight of the concrete wall, which is manifested as the step-by-step application of wind loads.

[0047] Option 2: Release the weight once, then place the sandbags in stages, see attached Fig.13 ;

[0048] Considering the one-time impact of its own weight on the wall panels, the wall panels were placed on the end horse stools and left to stand for a day, and then 35kg sandbags were placed in stages;

[0049] The structure diagram of the horse stool used in the test process is detailed in the attached Fig.14 and attached Fig.15 ;

[0050] This scheme aims to explore the influence of concrete plastic development on the test results. By recording the time when cracks appear and the width of cracks under self-weight conditions, the time of graded load holding during Scheme 1 is explored, and finally the time of continuous load application in Scheme 1 is guided by this time.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention uses a theodolite to determine the position and elevation of the fence according to the drawings and compares the on-site slopes. The foundation is set in a stepped shape according to the ground elevation, with a cross-section length of 1400mm, a width of 800mm, and a height of 300mm. It is equipped with corresponding steel bars to ensure shear resistance and bending resistance. The slope is excavated with a slope ratio of 1:0.5, a working surface width of 300mm, and a digging depth of at least 900mm. A formula for the excavation volume of soft soil is given, and the slope coefficient is determined according to the soil type. The base is compacted so that the foundation bearing capacity is ≥100kPa and the compaction coefficient is ≥0.94. A C15 cushion layer is poured with a thickness of at least 10cm. The foundation is tied according to the drawing. The short column steel bar has a lower bend anchor of 300mm and an upper bend anchor of 100mm, with a diameter of 10mm. A formula for calculating the length of the bend anchor is given. After the foundation is poured, embedded parts are installed, and then short columns are poured. The foundation After 3 days of maintenance, backfill is carried out, and the prefabricated parts are transported to the site. The base of the column and the short column steel plate are welded and sealed with waterproof mortar. After the column is installed, the wall panel is hoisted and clamped, and the seams are sealed with mortar. A finished fixture is used. A 100mm thick splashback is set outside the wall, 600mm away from the wall panel. Expansion joints are cut every 8m and filled with asphalt paste. Film maintenance is used. Dark gray is used for columns and wall caps, and white inorganic waterproof coating is used for wall panels. After grinding and putty leveling, brush it three times. The obtuse angle of the bend remains unchanged for columns and folded wall panels, and columns are added at right angles to install wall panels. The wall panels are installed by cutting the height difference. Compared with the traditional foundation treatment method, the present invention has a shorter construction period and a higher degree of ground hardening. It is suitable for soft soil surface layers of different horizontal planes. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 A top view of the invention;

[0054] Figure 2 A cross-sectional view of the basis of the present invention;

[0055] Figure 3 is a cross-sectional view of the foundation pit of the present invention;

[0056] Figure 4 A top view of the wall columns and wall panels of the present invention;

[0057] Figure 5 It is a schematic diagram of the water dispersion construction of the enclosure wall of the present invention;

[0058] Figure 6 It is a schematic diagram of the enclosure wall of the present invention when it is bent into an obtuse angle structure;

[0059] Figure 7 It is a schematic diagram of the enclosure wall of the present invention when it is bent into a right-angle structure;

[0060] Figure 8 It is a schematic diagram of the wall panel processing at the height difference position of the present invention;

[0061] Fig. 9 Schematic diagram of wind resistance performance test scheme 1 of the enclosure wall of the present invention Figure 1 ;

[0062] Fig.10 Schematic diagram of wind resistance performance test scheme 1 of the enclosure wall of the present invention Figure 2 ;

[0063] Fig.11 Schematic diagram of wind resistance performance test scheme 1 of the enclosure wall of the present invention Figure 3 ;

[0064] Fig.12 Schematic diagram of wind resistance performance test scheme 1 of the enclosure wall of the present invention Figure 4 ;

[0065] Fig.13 It is a schematic diagram of the wind resistance bearing performance test scheme 2 of the enclosure wall of the present invention;

[0066] Fig.14 It is a schematic diagram of the horse stool structure of the present invention;

[0067] Fig.15 for Fig.14 Sectional view of AA in the middle;

[0068] Fig.16 It is a schematic diagram of the wall columns and wall panels of the present invention.

[0069] The numbers in the figure represent:

[0070] 1. Foundation; 2. Foundation pit; 3. Wall columns; 4. Wall panels; 5. Short column reinforcement. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0072] The present invention will be further described below in conjunction with the embodiments.

[0073] Embodiment 1: In some embodiments, please refer to Figure 1-Figure 16 , a method for constructing an assembled railway security fence for soft soil, comprising the following steps:

[0074] Step 1: Basic 1 positioning, please refer to the attached Figure 1 and attached Figure 2 , the excavation of foundation pit 2 uses a theodolite to determine the position and elevation of the fence according to the fence coordinates and elevation of the drawings, and makes a comparative analysis based on the existing slope position and elevation on site. According to the ground elevation, foundation 1 adopts a stepped foundation 1. According to the load of the upper structure perpendicular to the horizontal plane, the cross-sectional dimensions of foundation 1 are arranged as 1400mm long and 800mm wide. In addition, in order to ensure the anti-punching performance of foundation 1, the height of foundation 1 is set to 300mm. In order to ensure the bending performance of foundation 1, 10@170 steel bars are arranged longitudinally in the upper and lower layers of foundation 1, with a steel bar diameter of 10mm and a spacing of 170mm. 10@150 steel bars are arranged transversely in the upper and lower layers of foundation 1, with a steel bar diameter of 10mm and a steel bar spacing of 150mm.

[0075] Step 2: Excavation of foundation pit 2, please refer to the attached Figure 3 , Foundation pit 2 adopts slope excavation, and the slope ratio and working face width are controlled according to the design requirements, that is, the slope ratio is 1:0.5, the working face width is 300mm, and the excavation depth is at least 900mm. In addition, a calculation formula for the excavation volume for soft soil is proposed;

[0076] Step 2.1: When foundation 1 excavation does not require slope, the following formula can be used to calculate the excavation volume:

[0077] V 挖 =L×(B+2C)×H

[0078] Where: V 挖 : indicates excavation volume (cubic meters); L: indicates excavation length (meters); B: indicates foundation 1 width (meters); C: indicates working surface width (meters), which is usually increased to ensure normal operation of workers; H: indicates excavation depth (meters), which is generally based on the designed outdoor floor elevation;

[0079] Step 2.2: When foundation 1 excavation requires slope reduction, the width of the slope reduction is calculated based on the slope reduction coefficient K, i.e. KH. At this time, the following formula can be used to calculate the excavation volume:

[0080] V 挖 =L×(B+2C+KH)×H

[0081] Alternatively, for the case of rectangular pit grading, a more detailed formula can be used:

[0082] V 挖 =(a+2c+KH)×(b+2c+KH)×H+1 / 3K2H 3

[0083] Where: a, b: represent the length and width of the rectangular pit respectively (meters); c: represents half of the width of the working surface (meters); K: represents the slope coefficient, which is determined according to the soil type; H: represents the excavation depth (meters);

[0084] Step 2.3, the slope coefficient K is determined according to the soil type. Generally speaking, the slope coefficient of Class I and Class II soil is 0.5, Class III soil is 0.33, and Class IV soil is 0.25. These coefficients are determined based on the physical and mechanical properties of the soil and the stability requirements of the excavation project;

[0085] Step 3: pouring cushion layer concrete. After excavation, compact the base to ensure that the foundation bearing capacity and compaction coefficient meet the use requirements. After compaction, pour the concrete cushion layer. The cushion layer concrete adopts C15 and the thickness must be at least 10cm, that is, the foundation bearing capacity ≥100kPa and the compaction coefficient ≥0.94;

[0086] Step 4: Foundation 1 construction, please refer to the attached Figure 2 , the foundation 1 is tied according to the design drawings, and the length of the lower and upper bent anchors of the short column steel bar 5 must meet the calculation requirements (the bent anchor refers to the anchor after the steel bar is bent, that is, the end of the steel bar is bent, generally made into a right-angle hook), that is, the lower bent anchor length of the short column steel bar 5 is 300mm, the upper bent anchor length is 100mm, and the diameter of the short column steel bar 5 is 10mm. Among them, the calculation formulas for the lower and upper bent anchor lengths are as follows:

[0087] Step 4.1, calculation formula for lower bend anchor length:

[0088] For the lower bent anchor, its length usually needs to be calculated based on factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The general formula can be expressed as:

[0089] Lower bend anchor length = steel bar diameter × bend anchor multiple

[0090] Among them, the bending anchor multiple is a coefficient that combines many factors, which depends on the seismic level, steel bar diameter, concrete strength, etc.

[0091] Step 4.2: Calculation formula for upper bend anchor length:

[0092] The calculation of the length of the upper bend anchor is similar to that of the lower bend anchor. It is also necessary to consider factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The calculation formula can be expressed as:

[0093] Upper bend anchor length = steel bar diameter × bend anchor multiple + beam height - protective layer thickness

[0094] Among them, beam height refers to the height from the bottom of the beam to the top of the beam, and the thickness of the protective layer refers to the distance from the steel bar to the concrete surface;

[0095] Step 5: Foundation 1 and short columns are poured in two times. After the concrete pouring of foundation 1 is completed, the embedded parts are installed, and then the short column concrete is poured. After the concrete pouring of foundation 1 is completed, geotextile is used to cover it and continuously sprinkle water for 3 days before backfilling;

[0096] Step 6: Installation of fence columns 3. Transport the fence columns 3 and wall panels 4 prefabricated in the processing plant to the site. Select a suitable crane according to the weight of the fence columns 3 and wall panels 4, and use the "one-point lifting method" for lifting construction. During installation, the base steel plate of the fence column 3 and the short column steel plate are fully welded. The weld width should meet the calculation requirements. After the weld is cooled, use waterproof mortar to seal and protect the weld and steel plate;

[0097] Step 7: Install wall panel 4, please refer to the attached Figure 4 After the installation of the wall columns 3 on both sides is completed, the wall panels 4 are hoisted between the wall columns 3 and clamped, and the gaps are sealed with mortar. The wall panels 4 are hoisted using commercially available finished hoisting fixtures;

[0098] Step 8: Spreading water construction, please refer to the attached Figure 5 The wall water diversion is cast with concrete of certain thickness and strength, and the outer side is 4600mm away from the wall panel. After the concrete is cast, it needs to be covered with film and watered to prevent the diversion from cracking. The diversion thickness is 100mm. The diversion cuts an expansion joint every 8m, with a width of 10mm and a depth of 30mm. After cutting, the joint is filled with asphalt paste.

[0099] Step 9: Surface coating construction: dark grey inorganic waterproof coating is used for the surface of wall columns 3 and wall caps, and white inorganic waterproof coating is used for the surface of wall panels 4. In addition, the concrete surface slurry needs to be polished before painting to ensure that the concrete surface is smooth and tidy. Waterproof putty needs to be used to level the local areas, gaps, depressions, and pits. Three coats of waterproof coating are used for painting;

[0100] Step 10: Special position processing, please refer to the attached Figure 6 and attached Figure 7 ;

[0101] 1. Because the wall is bent, the wall columns 3 and wall panels 4 at the bend need to be processed separately. Please refer to the attached Figure 6 When the fence is bent into an obtuse structure, the fence column 3 remains unchanged, one of the wall panels 4 is bent at one end close to the fence column 3, and then installed normally on the fence column 3; please refer to the attached Figure 7 When the fence is bent into a right-angle structure, two fence posts 3 are installed at the right-angle position, and two wall panels 4 at the right-angle position are respectively installed on one of the fence posts 3;

[0102] 2. For the treatment of wall panels at different heights, please refer to the attached Figure 8 , the foundation 1 remains unchanged, the lower side of the wall panel 4 is cut along the height difference, a bulge is formed at the lower position, and then the wall panel 4 is installed normally on the wall column 3.

[0103] In addition, a test method for the wind bearing performance of precast concrete assembled enclosures is provided, wherein the test is carried out according to the following two schemes:

[0104] Option 1: Release the deadweight in stages, then place sandbags in stages. Fig. 9 , Attachment Fig.10 , Attachment Fig.11 and attached Fig.12 ;

[0105] Considering that when the wall panel 4 is placed horizontally, the deadweight of the wall panel 4 itself is not conducive to the force on the wall panel 4, so a graded release support constraint form is adopted to change the mid-span deflection (the mid-span deflection refers to the distance between the highest point on both sides of the centerline of the cross-section curve and the centerline) to achieve a graded change in the mid-span bending moment (the mid-span bending moment refers to the bending moment at the midpoint of the span of the beam or a part of the beam), and then achieve graded loading of the deadweight. First, the support is released under the deadweight condition, aiming to gradually convert the deadweight of the concrete itself into wind load. After all the mid-span supports under the deadweight condition are released, 20kg sandbags are placed in stages until the specimen is destroyed, in order to explore its maximum limit bearing performance;

[0106] This scheme reduces the number of lower supports to increase the spacing between supports and to increase the mid-span curved rectangular shape, thus achieving graded application of wind loads, namely:

[0107] 1) Calculation: M = αql2 = 0.107ql2, four-span continuous beam;

[0108] 2) Calculation: M = αql2 = 0.116ql2, three-span continuous beam;

[0109] 3) Calculation: M = αql2 = 0.125ql2, single-span continuous beam, where the α coefficient is determined according to the specific support spacing.

[0110] It is easy to see that when the support spacing changes, the maximum mid-span bending moment changes accordingly, which is equivalent to the release of the deadweight of the concrete wall, which is manifested as the step-by-step application of wind loads.

[0111] Option 2: Release the weight once, then place the sandbags in stages, see attached Fig.13 ;

[0112] Considering the one-time effect of its own weight on the wall panel 4, the wall panel 4 was placed on the end horse stool and left to stand for one day, and then 35kg sandbags were placed in stages;

[0113] The structure diagram of the horse stool used in the test process is detailed in the attached Fig.14 and attached Fig.15 ;

[0114] This scheme aims to explore the influence of concrete plastic development on the test results. By recording the time when cracks appear and the width of cracks under self-weight conditions, the time of graded load holding during Scheme 1 is explored, and finally the time of continuous load application in Scheme 1 is guided by this time.

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing an assembled railway security fence for soft soil, characterized in that: The following steps are involved: Step 1: Positioning of foundation (1) and excavation of foundation pit (2) Using a theodolite to determine the position and elevation of the wall according to the coordinates and elevation of the wall in the drawing, and making a comparative analysis based on the position and elevation of the existing slope on site, the foundation (1) adopts a stepped foundation (1) according to the ground elevation, and the foundation (1) is based on the load of the upper structure perpendicular to the horizontal plane; Step 2: Excavation of foundation pit (2). Foundation pit (2) is excavated by slope reduction. The excavation volume calculation formula for soft soil is proposed: Step 2.1: When the excavation of foundation pit (2) does not require slope reduction, use the following formula to calculate the excavation volume: V 挖 =L×(B+2C)×H Where: V 挖 : indicates excavation volume; L: indicates excavation length; B: indicates foundation (1) width; C: indicates working surface width; H: indicates excavation depth; Step 2.2: When the excavation of foundation pit (2) requires slope reduction, the width of the slope reduction is calculated according to the slope reduction coefficient K, i.e. KH, and the excavation volume is calculated using the following formula: V 挖 =L×(B+2C+KH)×H Step 2.3: For rectangular pit slope, use a more detailed formula: V 挖 =(a+2c+KH)×(b+2c+KH)×H+1 / 3K2H 3 Among them: a, b: represent the length and width of the rectangular pit respectively; c: represents half of the width of the working surface; K: represents the slope coefficient; H: represents the excavation depth; Step 2.3, determine the slope coefficient; Step 3: pouring the cushion layer concrete. After the excavation is completed, the base is compacted. After the compaction is completed, the concrete cushion layer is poured. The cushion layer concrete adopts C15; Step 4: Construction of foundation (1), tying of short column reinforcement (5); Step 5: The foundation (1) and the short column are poured in two steps. After the foundation (1) concrete pouring is completed, the embedded parts are installed, and then the short column concrete is poured; Step 6: Installation of wall columns (3); Step 7: Wall panel (4) installation; Step 8: Bulk water construction; Step 9: Surface coating construction; Step 10: Special location processing.

2. The method for constructing an assembled railway security fence for soft soil according to claim 1, characterized in that: Step 2 also includes: slope ratio 1:0.5, working surface width 300mm, and excavation depth of at least 900mm.

3. The method for constructing an assembled railway security fence for soft soil according to claim 2, characterized in that: Step 2 also includes: the slope coefficient K is determined according to the soil type. The slope coefficient of Class I and Class II soil is 0.5, that of Class III soil is 0.33, and that of Class IV soil is 0.

25.

4. The method for constructing an assembled railway security fence for soft soil according to claim 3, characterized in that: Step three also includes: the thickness of the cushion layer concrete must be at least 10cm, that is, the foundation bearing capacity ≥100kPa, and the compaction coefficient ≥0.

94.

5. The method for constructing an assembled railway security fence for soft soil according to claim 4, characterized in that: Step 4 also includes: the length of the lower bent anchor and the upper bent anchor of the short column steel bar (5) must meet the calculation requirements (the bent anchor refers to the anchor after the steel bar is bent), that is, the lower bent anchor of the short column steel bar (5) is 300 mm long, the upper bent anchor is 100 mm long, and the diameter of the short column steel bar (5) is 10 mm. The calculation formulas for the lower and upper bent anchor lengths are as follows: Step 4.1, formula for calculating the length of the lower bend anchor: For the lower bent anchor, its length usually needs to be calculated based on factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The formula can be expressed as: Lower bend anchor length = steel bar diameter × bend anchor multiple Among them, the bending anchor multiple is a coefficient that combines many factors, which depends on the seismic level, steel bar diameter, concrete strength, etc. Step 4.2: Calculation formula for upper bend anchor length The calculation of the length of the upper bend anchor is similar to that of the lower bend anchor. It is also necessary to consider factors such as the diameter of the steel bar, the strength of the concrete, and the seismic resistance level. The calculation formula can be expressed as: Upper bend anchor length = steel bar diameter × bend anchor multiple + beam height - protective layer thickness Among them, the beam height refers to the height from the bottom of the beam to the top of the beam, and the protective layer thickness refers to the distance from the steel bar to the concrete surface.

6. The method for constructing an assembled railway security fence for soft soil according to claim 5, characterized in that: Step 5 also includes: (1) After the foundation concrete is poured, it is covered with geotextile and continuously watered for 3 days before backfilling.

7. The method for constructing an assembled railway security fence for soft soil according to claim 6, characterized in that: Step six also includes: transporting the prefabricated fence columns (3) and wall panels (4) in the processing plant to the site, selecting a suitable crane for lifting according to the weight of the fence columns (3) and the wall panels (4), and fully welding the base steel plates of the fence columns (3) and the short column steel plates during installation. The weld width should meet the calculation requirements, and after the weld is cooled, the weld and the steel plate are sealed and protected with waterproof mortar.

8. The method for constructing an assembled railway security fence for soft soil according to claim 7, characterized in that: Step seven also includes: hoisting the wall panel (4) between the wall columns (3) and clamping them, and sealing the gaps with mortar.

9. The method for constructing an assembled railway security fence for soft soil according to claim 8, characterized in that: Step eight also includes: the wall's water dispersion is cast with concrete, the outer side is 600mm away from the wall panel (4), after the concrete is cast, it is covered with a film and watered for maintenance, and expansion joints are cut every 8m in the water dispersion, with a width of 10mm and a depth of 30mm, and the cut joints are filled with asphalt paste.

10. The method for constructing an assembled railway security fence for soft soil according to claim 9, characterized in that: Step nine also includes: the wall columns (3) and the wall cap surface layer of the wall columns (3) are coated with dark grey inorganic waterproof paint, and the wall panels (4) are coated with white inorganic waterproof paint, both of which are applied three times. In addition, the concrete surface slurry needs to be polished before painting, and waterproof putty needs to be used to level the local areas, cracks, depressions, and rough surfaces.

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