JP2011017184A - Retaining wall and method of constructing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To position buttresses and a spindle-shaped foundation at the highest (shallowest) possible position and extend intervals between piles in a retaining wall having buttress and the spindle-shaped foundation.SOLUTION: The retaining wall (1) includes columns (2) and main piles (3) arranged at intervals, wall bodies (6) arranged between adjacent columns, buttresses (7) of a reinforced concrete structure projecting from the columns into the high ground, and the beam-like spindle-shaped foundation (8) of the reinforced concrete structure integrated with front ends of the buttresses and laterally extending in a manner of connecting adjacent buttresses to each other. Auxiliary piles (10) are arranged between the front ends of the buttresses. Upper ends of the auxiliary piles are integrated with the beam-like spindle-shaped foundation.

Description

  The present invention relates to a retaining wall and a construction method thereof, and more particularly, to a retaining wall of a wet construction method and a construction method thereof capable of exhibiting high stability and rigidity without a large footing. .

  It is necessary to install a retaining wall to prevent the ground from collapsing on cliffs caused by cuts exceeding 2m in height, embankments exceeding 1m in height, or in grounds where height differences occur, such as steep slopes or waterways. Occurs. The retaining wall is made of a reinforced concrete structure or a wall made of precast concrete products or concrete blocks.

  Such a retaining wall is usually designed with an L-shaped section or a T-shaped section as a whole, and a relatively large foundation footing is formed at the bottom of the retaining wall. The foundation footing functions to ensure a wide contact area for transmitting the load acting on the retaining wall (earth pressure) and the weight of the retaining wall to the supporting ground and to prevent the retaining wall from falling.

  Since the foundation footing extends relatively large toward the high ground side, it is necessary to excavate the high ground extensively during the retaining wall construction and backfill the excavated portion after the retaining wall construction. However, extensive excavation and backfilling of high ground causes problems such as a great amount of excavation work, an increase in the amount of moving soil, and instability of backfill soil. In addition, depending on the environment, conditions, or topography of the construction site, it may be difficult to construct a large foundation footing.

  In order to solve such problems of foundation footing construction, the retaining wall structure of the dry construction method configured to give the bending moment on the non-falling side to the steel main pile that constitutes the support in advance is published in Patent No. 2824217 It is disclosed in the publication.

  The present inventor integrates the reinforced concrete structure upright arranged directly above the pile and the underground beam-shaped foundation of the reinforced concrete structure that supports the vertical load of the wall body in such a retaining wall structure. Japanese Patent Application No. 2005-113760 (Japanese Patent Application Laid-Open No. 2006-291575) discloses a retaining wall of a wet construction method in which a buttress having a structure protrudes behind the retaining wall and a beam-shaped spindle foundation is connected to the buttress tip. Proposed in

  In this way, in the retaining wall equipped with a reinforced concrete buttress and a weight foundation, the center of gravity of the retaining wall is displaced to the high ground side by the weight of the buttress and the weight foundation, and the frictional force between the buttress wall surface and the ground is The falling of the retaining wall can be effectively prevented by the frictional force between the spindle foundation and the ground.

Publication No. 2824217 JP 2006-291575 A

  In order to shorten or reduce the excavation process and its labor in the retaining wall with such a structure, and to effectively reduce the amount of excavated soil, waste soil, and backfill soil, the buttress and the weight foundation are positioned as high as possible. In other words, it is desirable to arrange it as close as possible to the ground surface on the high ground side. However, in actuality, considering the falling or sliding of the retaining wall or the lift of the buttress and the weight-shaped foundation, the buttress and the weight-shaped foundation are deeply excavated from a relatively low position, that is, the ground surface on the high ground side. There are many cases that must be placed in position.

  Moreover, in order to make each pile exhibit sufficient pile strength, it is necessary to ensure the space | interval of an adjacent pile enough, and it is desirable to expand a pile space | interval. Expansion of the pile interval also means a decrease in the number of piles and columns, which is economically advantageous. However, if the pile interval is enlarged, the horizontal force that each pile should support increases. In addition, considering the stability of the ground between the piles, there is a situation where it is difficult to increase the pile interval as desired.

  The present invention has been made in view of such circumstances, and an object of the present invention relates to a retaining wall having a buttress and a weight-shaped foundation, and the position of the buttress and the weight-shaped foundation as high as possible (the ground on the high ground side). It is to provide a retaining wall that can be positioned at a position where the excavation depth from the surface is shallow) and can increase the interval between piles, and a construction method therefor.

In order to achieve the above object, the present invention provides a column and a main pile that are spaced apart from each other, a wall disposed between the adjacent columns, and a reinforced concrete structure that protrudes from the column into a high ground. In a retaining wall having a buttress and a beam-shaped pyramid base of a reinforced concrete structure that is integrated with the tip of the buttress and extends laterally so as to interconnect adjacent buttresses,
The retaining wall is provided between the front ends of the buttress and has an auxiliary pile whose upper end is integrated with the beam-shaped pyramid foundation.

  The present invention is also a method for constructing a retaining wall having the above-described configuration, in which a cast-in-place concrete pile or a prefabricated pile is constructed as the auxiliary pile between the end portions of the buttress, and the beam weight is directly above the auxiliary pile. A method for constructing a retaining wall is provided, wherein a shape foundation is constructed, and an upper end portion of the auxiliary pile and the beam-shaped spindle foundation are integrated.

  According to the above-described configuration of the present invention, the retaining wall shaft includes a vertical shaft member composed of columns and main piles, a wall disposed between the columns, a buttress and a beam disposed behind the columns. It is comprised from a weight-shaped foundation and the auxiliary pile extended below from a beam-shaped weight-shaped foundation. The earth pressure of the high ground is mainly supported by the horizontal supporting force of the main pile and the auxiliary pile, and the frictional force between the beam-shaped spindle foundation, buttress and the ground. The beam-shaped pyramidal foundation, buttress and auxiliary pile act to displace the center of gravity of the retaining wall toward the high ground side, increase the stability moment of the retaining wall, and prevent the retaining wall from falling. Further, according to the present invention, the pull-out resistance of the auxiliary pile acts so as to prevent the retaining wall from overturning. For this reason, it is possible to reduce the weight of the soil that should act on the beam-shaped pyramid foundation and the buttress in order to secure a stable moment. Therefore, the buttress and the beam-shaped pyramid foundation can be placed at a high position (from the ground surface on the high ground side). Can be positioned at a position where the excavation depth is shallow.

  Moreover, an auxiliary pile partially bears the horizontal support force which a main pile should bear, and reduces the load of a main pile. Auxiliary piles are also placed in the span area between the main piles to stabilize the high ground G. For this reason, the space | interval (space | interval of a pillar) of a main pile can be expanded.

  According to the present invention, in the retaining wall having a buttress and a weight-shaped foundation, the buttress and the weight-shaped foundation are positioned as high as possible (position where the excavation depth from the ground surface on the high ground side is shallow), and the main pile The interval (column interval) can be increased.

FIG. 1 is a partially broken perspective view showing an embodiment of a retaining wall according to the present invention. FIG. 2 is a longitudinal sectional view of the retaining wall shown in FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 is a cross-sectional view taken along line BB in FIG. FIG. 5 is a cross-sectional view schematically showing the reinforcement of columns, main piles, auxiliary piles, buttresses and beam-shaped pyramid foundations. It is a load distribution diagram which shows roughly distribution of load which acts on a retaining wall.

  According to a preferred embodiment of the present invention, the inclination angle (θ) of the lower end surface of the buttress with respect to the horizontal ground surface is set to an angle of 45 ° or more. Preferably, the distance (J) between the ground surface of the high ground and the upper end surface of the buttress is set within a range of 1/4 to 1/6 of the height (H) of the retaining wall.

  According to a further preferred embodiment of the present invention, the main pile and the auxiliary pile are arranged in a staggered arrangement in the direction of the wall core of the retaining wall. Preferably, the lower end portion of the auxiliary pile is located below the ground surface of the low ground. More preferably, the distance (M) between the lower end of the auxiliary pile and the ground surface of the low ground is set to a dimension of 1 m or more.

  Preferably, the ratio (E / H) between the distance (E) between the pile cores between the main pile and the auxiliary pile and the height (H) of the retaining wall is set to 1.0 or less. In addition, the distance (E) between pile cores is the dimension measured in the direction orthogonal to the wall body of a retaining wall.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a partially broken perspective view showing an embodiment of a retaining wall according to the present invention, and FIG. 2 is a longitudinal sectional view of the retaining wall shown in FIG.

  The retaining wall 1 includes pillars 2 having a square cross section arranged at intervals in the wall core direction. A main pile 3 is arranged directly below each pillar 2. The axial centers of the pillar 2 and the main pile 3 coincide, and the pillar 2 and the main pile 3 are aligned vertically. The column 2 is composed of a vertical standing column having a reinforced concrete structure, and the main pile 3 is composed of a cast-in-place concrete pile having a circular cross section. In this example, the depth N of the front-end | tip part (lower end part) of the main pile 3 is set in the range of about 3-7m from the ground surface La. The pillar 2 and the main pile 3 constitute a vertical shaft member of the retaining wall 1.

  An underground beam-shaped foundation 4 having a reinforced concrete structure interconnecting the column bases of the columns 2 extends in the direction of the wall core of the retaining wall 1, and the wall body 6 is constructed on the foundation 4. The wall body 6 consists of a reinforced concrete wall having a wall thickness of about 25 to 30 cm. In this example, the column 2 and the wall body 6 have a height H substantially equal to the depth N of the main pile 3, and the height H is set within a range of about 3 to 5 m from the ground surface La. Yes. The foundation 4 has a rectangular beam-shaped cross section having a strong axis (a weak axis in the horizontal direction) extending in the vertical direction, and has bending rigidity and shear rigidity that can withstand vertical load and horizontal load acting on the foundation 4. The foundation 4 constitutes a horizontal axis member of the retaining wall 1 that interconnects adjacent vertical axis members (column 2 and main pile 3). In addition, it is also possible to construct | assemble the wall 5 with the PC block (precast concrete block) for retaining walls. For example, the PC block is constructed according to a known wet masonry method in which longitudinal and horizontal reinforcing bars are arranged in joints and hollow parts and then cement mortar is filled in the joints and hollow parts.

  A buttress (retaining wall) 7 is disposed behind the pillar 2. The buttress 7 is made of a reinforced concrete wall body integrated with the back surface of the column 2 and protrudes from the back surface of the column 2 to the high ground G side. For example, when the retaining wall 1 extends straight and straight, the construction surface of the buttress 7 extends in a direction orthogonal to the construction surface of the wall body 6. If desired, the surface of buttress 7 may be oriented in a direction that forms an arbitrary angle with respect to wall 6.

  The upper end surface 7a of the buttress 7 extends horizontally toward the high ground G side, and the lower end surface 7b of the buttress 7 extends obliquely upward from the column base portion of the column 2 toward the high ground G.

  A highly rigid beam-shaped foundation 8 having a reinforced concrete structure is formed in the high ground G. The foundation 8 has a square cross section. The foundation 8 extends horizontally in the direction of the wall core. The ends of adjacent buttresses 7 are interconnected by a foundation 8. The cross-sectional dimension W × I of the foundation 8 is set to a size of about 700 × 700 to 1200 × 1200. The foundation 8 displaces the position of the center of gravity of the retaining wall 1 toward the high ground G by its own weight. Due to the displacement of the center of gravity of the retaining wall 1, a stable moment that acts to prevent the retaining wall 1 from falling is further obtained.

  The retaining wall 1 also has auxiliary piles 10 arranged at predetermined intervals along the foundation 8. The auxiliary pile 10 is a cast-in-place concrete pile having a circular cross section, and the upper end portion of the auxiliary pile 10 is integrated with the foundation 8. The auxiliary pile 10 extends vertically downward from the lower surface of the foundation 8, and the lower end portion (tip portion) of the auxiliary pile 10 is positioned below the ground surface La of the low ground L by a predetermined dimension M (1.0 m or more). The total value of the total length K of the auxiliary pile 10 and the height dimension I of the foundation 8 is substantially the same value as the height H of the retaining wall 1.

  3 and 4 are sectional views taken along lines AA and BB in FIG.

  The auxiliary pile 10 is disposed at the center of the column span S. Adjacent auxiliary piles 10 are separated from each other by a span T having the same dimensions as the column span S. The retaining wall 1 has the same number of auxiliary piles 10 as the main piles 3. Since the main pile 3 and the auxiliary pile 10 are arranged in a staggered arrangement along the retaining wall 1, it is possible to sufficiently secure the interval between the auxiliary piles 10 and to improve the stability of the high ground G. By improving the stability of the high ground G, the column span S can be expanded compared to the conventional retaining wall. For example, the column span S is about 2.0 to 3.0 m in the conventional retaining wall not provided with the auxiliary pile 10, whereas according to the retaining wall 1 of the present invention, the column span S is 4. It can be set in the range of 0 m or more, for example, 4.0 to 5.0 m.

  FIG. 5 is a cross-sectional view schematically showing the reinforcement arrangement of the pillar 2, the main pile 3, the buttress 7, the foundation 8, and the auxiliary pile 10.

  The main reinforcement 2a of the pillar 2 extends through the foundation 4 into the main pile 3 and is fixed to the concrete of the foundation 4 and the main pile 3. The main reinforcement 3a of the main pile 3 penetrates the foundation 4 into the pillar 2. It extends and settles on the concrete of the foundation 7 and the pillar 2. The foundation 8 has a main reinforcing bar 8a extending in the longitudinal direction of the foundation 8 (in the direction of the wall core of the retaining wall 1), and exhibits a proof strength that can withstand external forces such as a load acting on the foundation 8 and a shearing force. The buttress 7 has upper and lower main muscles 7c and 7d. The column side end of the main reinforcement 7c extends into the column 2 and is fixed to the concrete of the column 2, and the column end of the main reinforcement 7d penetrates the foundation 4 and extends into the main pile 3, and the foundation 4 and the main pile Fix to the concrete of No. 3. The outer ends of the main bars 7c and 7d extend into the foundation 8 and are fixed to the concrete of the foundation 8. The main reinforcement 10 a of the auxiliary pile 10 extends into the foundation 8 and is fixed to the concrete of the foundation 8. The pillar 2 and the piles 3 and 10 have hoops 2b, 3b and 10b.

  It is possible to use general-purpose deformed reinforcing bars of about D19 to D29 as the main bars 2a, 3a, 8a and 10a, and use general-purpose deformed reinforcing bars of about D13 to D19 as the hoops 2b, 3b and 10b and the stirrup muscle 8b. it can.

  In addition, the foundation 4 has the main reinforcement (not shown) extended in a wall core direction similarly to the foundation 8, and the stirrup reinforcement (not shown) surrounding the main reinforcement. A general-purpose deformed rebar of about D19 to D29 can be used as the main rebar of the foundation 4, and a general-purpose deformed rebar of about D13 to D19 can be used as the stirrup of the foundation 4.

  As shown in FIG. 2, the lower end surface 7b of the buttress 7 is inclined relatively steeply with respect to the horizontal ground surfaces La and Ga, and the inclination angle θ of the lower end surface 7b is 30 ° or more, preferably 45. It is set in the range of ° to 60 °. Preferably, the distance J between the ground surface Ga of the high ground G and the upper end surface 7a is about 1/4 to 1/6 of the height H of the pillar 2 and the wall body 6 (height of the retaining wall 1). For example, when the height H is 5.0 m, the distance J is set to 1.5 m or less, for example, J = 1.0 m. Preferably, the ratio E / H between the pile center distance E of the main pile 3 and the auxiliary pile 10 and the height of the column 2 and the wall body 6 (height of the retaining wall 1) H is set to 1.0 or less. Is done. The distance E between pile cores is a dimension measured in a direction orthogonal to the composition surface of the wall body 6.

  FIG. 6 is a load distribution diagram schematically showing the distribution of the load acting on the retaining wall 1.

  As shown in FIG. 6, the soil weight of the high ground G acts on the buttress 7 and the foundation 8, and horizontal earth pressure acts on the wall body 6 and the column 2. A ground spring and a ground supporting force act on the piles 3 and 10. The dead weight of the foundation 8 and the auxiliary pile 10 and the pulling resistance of the auxiliary pile 10 work as a stable moment against the overturning moment of the retaining wall 1 together with the soil weight of the high ground G.

  As shown in FIG. 2, since the foundation 8 is disposed at a position relatively close to the ground surface Ga of the high ground G, the weight of the soil above the buttress 7 and the foundation 8 is relatively small. Further, since the inclination angle θ of the lower end surface 7b is set to a relatively large angle, the horizontal distance (pile core distance E) between the wall core of the retaining wall 1 and the shaft core of the foundation 8 is relatively small. Set to dimension. Therefore, the excavation process and its labor can be shortened or reduced, and the amount of excavated soil, the amount of waste soil, and the amount of backfilled soil can be reduced.

  Further, when the foundation 8 is arranged at a position close to the ground surface Ga of the high ground G (shallow position) or when the angle θ is increased, the retaining wall 1 falls or slides, the buttress 7 and the foundation 8 are lifted, etc. However, in the retaining wall 1 of the present invention, the stability moment against the overturning moment is the friction between the buttress 7 and the foundation 8 and the ground, the weight (self-weight) of the auxiliary pile 10, Since it increases due to the pulling resistance, friction between the auxiliary pile 10 and the high ground G, etc., problems such as the falling or sliding of the retaining wall 1 and the lifting of the buttress 7 and the foundation 8 do not occur.

  Further, the auxiliary pile 10 partially bears the horizontal resistance to be borne by the main pile 3, reduces the load on the main pile 3, and is disposed in an inter-span region between the main piles 3, Stabilize. This increases the interval (span S) of the main piles 3 and makes it possible to reduce the number of main piles 3 (and columns 2) of the entire retaining wall 1.

  Next, the construction method of the retaining wall 1 will be described.

  In the construction of the retaining wall 1, the excavation range of the high ground G is limited to the extent that the piles 3, 10, the foundations 4, 8 and the buttress 7 can be constructed. That is, in the construction of the retaining wall 1, unlike the conventional retaining wall construction method, it is not necessary to excavate the high ground G for the footing construction.

  First, the high ground G is excavated to the minimum extent required to construct the piles 3, 10, foundations 4, 8 and buttress 7, and reinforcing bars are placed in the pile holes of the piles 3, 10; Concrete is placed in the hole, and cast-in-place concrete piles (pile 3, 10) are constructed. The main bars 2 a and 7 d of the pillar 2 and the buttress 7 are at least partially constructed simultaneously with the bar arrangement of the piles 3 and 10, and the main bars 2 a and 7 d are fixed to the concrete of the main pile 3.

Next, reinforcement of the foundation 4 and concrete placement are performed, and the foundation 4 is constructed.
After that, the reinforcement of the pillar 2, wall body 6, buttress 7 and foundation 8 and concrete placement are performed, and the pillar 2, wall body 6, buttress 7 and foundation 8 are constructed. After the concrete and mortar of each part is hardened, the excavated soil is backfilled to complete the construction of the retaining wall 1.

  According to the retaining wall 1 having such a configuration and the construction method thereof, the load of the retaining wall 1 is transmitted to the ground mainly by the columns 2 and the main pile 3 aligned vertically. Therefore, since the construction of large footings as in the prior art can be omitted, the excavation range can be limited, and the amount of excavated soil, waste soil and backfill soil can be reduced.

  Here, the foundation 4 constitutes a horizontal shaft assembly member that interconnects the vertical shaft assembly members (the pillars 2 and the main piles 3) to improve the rigidity of the retaining wall 1 as a whole, and the weight of the wall body 6 itself. And the load are transmitted to the vertical shaft members (column 2 and main pile 3). The buttress 7 not only improves the rigidity of the column 2 but also works to prevent the retaining wall 1 from falling due to the frictional force generated between the side surface of the buttress 7 and the ground. Further, the foundation 8 interconnects the buttresses 7 and improves the rigidity of the buttress itself. The foundation 8 also applies a vertical load to the tip of the buttress 7, and the weight of the buttress 7 and the foundation 8 displaces the center of gravity of the retaining wall 1 to the non-falling side. Thus, the falling of the retaining wall 1 due to earth pressure can be reliably prevented.

  Moreover, in the retaining wall 1 of this invention, the auxiliary pile 10 partially bears the horizontal resistance which the main pile 3 should bear, and reduces the load of the main pile 3. The auxiliary pile 10 is also disposed in the inter-span region between the main piles 3 to stabilize the high ground G. For this reason, it becomes possible to enlarge the space | interval (span S) of the main pile 3 (and pillar 2), and to reduce the number of the main pile 3 (and pillar 2). In addition, the stability moment against the overturning moment increases due to the weight (self-weight) of the auxiliary pile 10, the pulling resistance of the auxiliary pile 10, the friction between the auxiliary pile 10 and the high ground G, etc. Alternatively, sliding and lifting of the buttress 7 and the foundation 8 can be effectively prevented.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications or changes can be made within the scope of the present invention described in the claims. Is possible.

  For example, the above embodiment relates to a retaining wall having a straight wall body, but the present invention can be applied to various planar forms such as a retaining wall having a curved planar shape or a retaining wall bent at an angle. It may be applied to the retaining wall.

  Moreover, in the said Example, although the retaining wall 1 is provided with the pillar 2 and the foundations 4 and 8 of a square cross section, even if the cross section of a pillar and a foundation is designed in arbitrary forms, such as a square, a polygon, or an ellipse. good.

  Further, the form of the buttress 7 is not necessarily limited to a right triangle. For example, the lower end surface 7b may be curved, or the upper end surface 7a may be inclined.

  Moreover, in the said embodiment, although the cast-in-place concrete pile was employ | adopted as the piles 3 and 10, you may employ | adopt other types of piles, such as an existing RC pile, PC pile, and steel piles, as the piles 3 and 10.

  Furthermore, although the retaining wall of the said embodiment is a thing of the structure which has arrange | positioned the single auxiliary pile 10 in the center part of the column span S, it is also possible to arrange a plurality of auxiliary piles 10 within the range of the column span S. Is possible.

  The present invention is applied to a retaining wall constructed on a cliff, a steep slope, a water channel or the like. Since the retaining wall of the present invention does not require the construction of a large footing, the workability of the retaining wall is greatly improved. Further, according to the present invention, since the amount of excavation of the high ground can be reduced, it is possible to construct the retaining wall even in the ground where it has been difficult to construct the retaining wall with the conventional retaining wall structure. Furthermore, according to the present invention, in the retaining wall having the buttress and the weight-shaped foundation, the buttress and the weight-shaped foundation are positioned as high as possible (position where the excavation depth from the ground surface on the high ground side is shallow), Since the distance between piles and columns can be increased, the practical effect is remarkable.

DESCRIPTION OF SYMBOLS 1 Retaining wall 2 Column 3 Main pile 4 Underground beam type foundation 6 Wall body 7 Buttress 8 High rigidity beam type foundation 10 Auxiliary pile G High ground L Low ground

Claims (7)

Columns and main piles arranged at intervals, wall bodies arranged between adjacent columns, buttresses of reinforced concrete structure projecting from the columns into the high ground, and integrated with the tip of the buttress In a retaining wall having a beam-shaped pyramid base of a reinforced concrete structure extending in a lateral direction so as to interconnect adjacent buttresses,
A retaining wall, characterized in that the retaining wall has an auxiliary pile which is disposed between the tip portions of the buttress and whose upper end portion is integrated with the beam-shaped spindle foundation.   The retaining wall according to claim 1, wherein an inclination angle (θ) of a lower end surface of the buttress with respect to a horizontal ground surface is set to an angle of 45 ° or more.   The distance (J) between the ground surface of the high ground and the upper end surface of the buttress is set within a range of 1/4 to 1/6 of the height (H) of the retaining wall. Item 3. The retaining wall according to item 1 or 2.   The retaining wall according to any one of claims 1 to 3, wherein the main pile and the auxiliary pile are arranged in a staggered arrangement in the direction of the wall core of the retaining wall.   The retaining wall according to any one of claims 1 to 4, wherein a lower end portion of the auxiliary pile is located below a ground surface of a low ground.   The ratio (E / H) of the distance (E) between the pile cores between the main pile and the auxiliary pile in the direction orthogonal to the wall body and the height (H) of the retaining wall is 1.0. The retaining wall according to any one of claims 1 to 5, wherein the retaining wall is set as follows.   It is the construction method of the retaining wall described in any one of Claims 1 thru | or 6, Comprising: A cast-in-place concrete pile or an existing pile is constructed as the said auxiliary pile between the front-end | tip parts of the said buttress, A method for constructing a retaining wall, wherein the beam-shaped pyramid foundation is constructed immediately above, and the upper end portion of the auxiliary pile and the beam-shaped pyramid foundation are integrated.

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