CN100567659C - The basic structure of the tower - Google Patents

Abstract

The present invention provides a foundation structure of an iron tower. In a foundation structure form in which a plurality of piles with a relatively small diameter are arranged in a foundation, the construction time can be shortened and the amount of excavation can be reduced by making the foundation small-scale. Reduce the amount of concrete pouring, etc. In the foundation structure of the iron tower, the multiple piles (1, 1...) driven into the foundation and the main piles (2) of the iron tower are joined by a concrete structure (3), the concrete structure (3) is A structure made by pouring concrete (6) into a steel pipe (5) with multiple sections of shear flanges (4, 4...) fixed along the circumferential direction on the inner wall along the vertical direction, the concrete structure The lower side of (3) joins the tops of a plurality of piles (1, 1...) driven into the foundation, and a multi-section support plate (7) is provided on the outer surface of the lower part of the main pile (2) of the iron tower , 7...), the main pile part (K) provided with the support plate (7, 7...) is embedded in the concrete structure (3).

Description

The basic structure of the tower

technical field

The present invention relates to a foundation structure of an iron tower in which a plurality of piles driven into a foundation are joined to main piles of the iron tower through a concrete structure.

Background technique

As the basic structure supporting the main piles of the above-mentioned iron tower, when the supporting layer is relatively deep, as shown in Figure 6, after driving a plurality of piles 50, 50... with relatively small diameters into the foundation, use reinforced concrete It is common practice to form a footing 51 connecting the tops of these pile bodies 50, 50..., and to connect this footing 51 to the main pile 52 of the iron tower (see Patent Document 1, etc. below).

In addition, the fixing structure of the footing 51 and the main pile 52 can be roughly classified into a bolt fixing method, an anchor member fixing method, a support plate fixing method, and the like. As shown in Figure 6, the bolt fixing method is to utilize a plurality of anchor bolts 54, 54... to fix the base plate 53 on the bottom surface of the main pile 52. The above-mentioned anchor component fixing method is shown in Figure 7 (A)-(C). As shown, the installation plate 56 is fixedly installed on the lower peripheral surface of the main pile buried on the footing 51 by welding or the like, and the left and right paired angle steels 57, 57 are bolted to each other through the installation plate 56. Multiple fixing methods are arranged around, and the above-mentioned supporting plate fixing method is shown in FIG. 58, 58... The way to fix.

On the other hand, the joint method of the footing and the top of the pile is as follows: As shown in FIG. 59, 59... to fix the supporting plate joining method; or as shown in Fig. 9(B), a plurality of steel bars 60, 60... which traverse the top of the pile and the footing 51 are set and joined.

On the other hand, in order to realize the simplification of the foundation structure, in the following patent document 2 (see FIG. 10 ), a steel tower foundation structure is proposed. , 70 ... are pressed into the ground along the inclined direction, and the upper ends of the rotary press-in steel pipe piles 70, 70 ... are connected and fixed to the lower end of the iron tower foot 71. 70 and the iron tower foot 71 extending upwards are linear.

Patent Document 1: JP-9-3882 Gazette

Patent Document 2: JP-A-2003-166254 Gazette

As shown in Fig. 11, the foundation of the above-mentioned power supply tower is more strongly affected by the pay-out tension of the wire and wind load such as typhoon or monsoon than the influence of the tower's own weight and the wire's own weight. As a result, the overturning moment becomes large compared to the total compressive load due to other factors, so that a compressive load acts on the tower foot on the leeward side, and approximately the same compressive load acts on the tower foot on the windward side. 70% of the pull-out load (pull-out force) of the (press-fit force). And, due to the force couple generated by the above-mentioned pressing force and pulling force, a bending moment acts and a horizontal force acts.

Therefore, at the foundation (footing) supporting the foot of the iron tower, as shown in FIG. The cone-shaped shear crack 61 centered on the base leads to destruction of the fixed part. Moreover, as shown in FIG. 13 , when the pile body 50 is too close to the outer edge of the footing 51 , shear cracks 62 , 62 . In addition, when the footing is too thin, as shown in the figure, there may be problems such as a tapered shear crack 61 centered on the pile body 50 .

Therefore, if the footing 51 is designed to have sufficient resistance to these pressing force, pulling force, bending moment, and horizontal force without causing cracks, the scale of the footing will become larger, and the scale of the footing will also increase accordingly. The amount of excavation increased and the amount of concrete poured increased, and the construction required a lot of time and labor.

On the other hand, in the case of the foundation structure described in the above-mentioned Patent Document 2, since there is no footing, the above-mentioned problem is eliminated, but in order to drive the steel pipe pile 70 with a large diameter into the foundation, a large heavy machine is required, especially It is impossible or difficult to adopt this technology in the construction of iron tower foundations in mountainous areas.

Contents of the invention

Therefore, the main subject of the present invention is to provide a foundation structure of an iron tower. A plurality of piles with relatively small diameters are arranged in the foundation, which can make the foundation small-scale, thereby shortening the construction time, reducing the amount of excavation, and Reduce the amount of concrete poured, etc.

In order to solve the above problems, the present invention of technical scheme 1 provides a basic structure of an iron tower, and a plurality of piles driven into the foundation are connected with the main piles of the iron tower through a concrete structure, wherein the above-mentioned concrete structure is A structure made by pouring concrete into a steel pipe with a plurality of segments of shear flanges fixed in the circumferential direction on the inner wall surface, and a plurality of piles driven into the foundation are joined to the lower side of the concrete structure The top of the body, and the lower part of the main pile of the iron tower is provided with a fixing part, and the main pile with the fixing part is partially buried in the above-mentioned concrete structure.

In the present invention described in the above-mentioned technical solution 1, as a concrete structure that joins a plurality of piles driven into the foundation first and the main pile of the iron tower, the concrete structure is poured into the inner wall surface to have a plurality of sections along the vertical direction. A structure made in a steel pipe with shear flanges fixed in the circumferential direction.

In the past, the design of the fixing part of the main pile of the iron tower was strengthened by the fixing endurance based on the allowable tensile stress and the allowable shear stress of the concrete. , perform reinforcement according to empirical rules, and thus sometimes overreinforce. In view of the above situation, the present applicant has intensively discussed effective foundation design and reinforcement, and as a result, as disclosed in JP-A-2000-345571, when continuous stress acts on the main pile, horizontal stresses are generated on the concrete. Cracks or vertical cracks (slit cracks). Furthermore, it was found that, in the case of the support fixing method, the above-mentioned split cracks are greatly affected, and when the split cracks are generated, even if one of the cracks reaches the surface of the foundation, damage occurs. In addition, the applicant obtained the following insights based on more than a dozen model experiments and numerical analysis: using steel pipes to strengthen the direction perpendicular to the split crack, that is, the circumferential direction of the main pile, can improve the restraint of concrete and suppress split damage, which can greatly improve the Improves stationary stamina.

Therefore, if splitting cracks can be suppressed as much as possible, in order to improve the fixing resistance and reduce the joint part (foundation part), as the concrete structure of the above structure, a plurality of piles driven into the above foundation are joined at the lower side. The top of the tower, and the lower part of the main pile of the iron tower is provided with a fixed part, and the main pile with the fixed part is partially embedded in the foundation structure of the concrete structure.

As a result, the steel pipe constrains the poured concrete from the outside (surroundings), prevents splitting cracks, and greatly improves the fixation resistance of the concrete structure. In addition, the pile body can be placed close to the inner wall surface of the steel pipe, so it can be greatly reduced. The scale of small concrete structures. Furthermore, by reducing the scale of the concrete structure, it is possible to shorten the construction time, reduce the amount of excavation, reduce the amount of pouring concrete, and the like.

Furthermore, by forming the concrete structure made of the above-mentioned steel pipes and concrete, it is possible to easily install a plurality of pile bodies, and it is easy to absorb construction errors of the main pile and the auxiliary pile.

The present invention as claim 2 provides a foundation structure of an iron tower according to claim 1, wherein the plurality of piles are small-diameter piles with a diameter of 400φmm or less or 1/6 or less of the steel pipe diameter. As the pile body, it is desirable to install a plurality of, preferably 4 to 6, small-diameter piles with a diameter of 400mm or less compared with the large-diameter pile body, or with a diameter of 1/6 or less of the above-mentioned steel pipe diameter. Especially in mountainous areas, since large heavy machinery cannot be used, it is preferable to install the required number of small-diameter piles in the foundation using a small-sized hole-digging machine. The small-diameter piles may be in-situ cast-in-place piles or steel pipe piles, as will be described later in detail.

The present invention according to claim 3 provides the steel tower foundation structure according to claim 1 or 2, wherein the shear flanges are respectively provided on the upper side of the steel tower main pile with the supporting plate arrangement part as a boundary. and lower side.

In the present invention described in claim 3 above, the shear flanges are respectively provided on the upper side and the lower side of the support plate arrangement portion of the embedded portion of the tower main pile as a boundary. The load from the main pile acting on the concrete structure sometimes includes both the indentation force and the pull-out force due to the direction of the wind load or earthquake load, so for both of the loads, in order for the above-mentioned shear flange to function effectively , are preferably provided on the upper side and the lower side of the support plate arrangement portion as a boundary, respectively.

The present invention according to Claim 4 provides the foundation structure of the iron tower according to any one of Claims 1 to 3, wherein most of the concrete structure is buried in a foundation.

The above-mentioned concrete structure can also be built by placing it on the ground, but in order to suppress the displacement of the foundation, it is preferable to bury it underground like the footing, and build it in a state where the displacement can be suppressed by the earth pressure resistance.

The present invention related to technical scheme 5 provides a kind of basic structure according to any one of technical scheme 1 to 4 iron tower, suppose the diameter of above-mentioned iron tower main pile column is φ, the configuration interval of the supporting plate of above-mentioned iron tower main pile column When the length is L and the inner diameter of the steel pipe is D, the following conditions are satisfied: L/φ=2-5, and D/φ=2-10.

The present invention according to claim 6 provides the foundation structure of an iron tower according to any one of claims 1 to 5, including slope piles driven obliquely downward from the steel pipe peripheral wall portion of the concrete structure.

In the present invention according to Claim 6 above, slope piles are provided which are driven obliquely downward from the steel pipe peripheral wall portion of the concrete structure. In particular, by providing slope piles, the pull-out endurance can be significantly improved.

The present invention related to technical solution 7 provides a foundation structure of an iron tower according to any one of technical solutions 1 to 5, which has a connecting beam connecting the concrete structures of the main piles of adjacent iron towers.

In the present invention according to the above-mentioned technical solution 7, there is provided a connecting beam between the concrete structures connecting the main piles of adjacent iron towers. By connecting the concrete structure with the connecting beam, the displacement of the foundation can be significantly suppressed.

In the present invention according to Claim 8, there is provided the foundation structure of an iron tower according to any one of Claims 1 to 5, wherein the number of main piles of the iron tower is 2 to 4. Instead of larger steel tube columns, superstructures with 2 to 4 truss-structured columns can be used, and in the case of small-scale iron towers, all 4 main columns can be fixed in one said steel tube.

Invention effect

As described in detail above, according to the present invention, in the form of foundation structure in which a plurality of piles with relatively small diameters are installed in the foundation, as a concrete structure, concrete is poured into the inner wall surface and has a plurality of sections along the circumference along the upper and lower directions. The structure is made in the steel pipe with the shear flange fixed in the direction, so the fixing resistance can be greatly improved, and the base part can be reduced in size. As a result, the construction time can be shortened, the amount of excavation can be reduced, the amount of concrete pouring can be reduced, and the like.

Description of drawings

Fig. 1 shows the basic structure of the steel tower of the first embodiment, (A) is a longitudinal sectional view, (B) is a transverse sectional view.

Fig. 2 shows the basic structure of the iron tower of the second embodiment, (A) is a longitudinal sectional view, (B) is a right side view, and (C) is a transverse sectional view.

Fig. 3 is a longitudinal sectional view showing a basic structure of a steel tower according to a third embodiment.

FIG. 4 is a longitudinal sectional view showing a modified example of the main pile 2 .

FIG. 5 is diagrams (A) to (C) of form examples of the shear flange 4 .

Fig. 6 shows the basic structure of a conventional iron tower, (A) is a longitudinal sectional view, and (B) is a transverse sectional view.

Fig. 7 shows the anchor member fixing method of the main pile 52, (A) is a longitudinal sectional view of the footing, (B) is a top view of the anchor member, and (C) is a side view of the anchor member.

Fig. 8 shows the supporting plate fixing method of the main pile 52, (A) is a longitudinal sectional view, and (B) is a transverse sectional view.

Fig.9 (A) is a figure which shows the support plate fixing form of the pile body 50, (B) is a figure which shows the reinforcing bar fixing form.

Fig. 10 is a side view showing a basic structure of a simple iron tower in a conventional example.

Fig. 11 is a state diagram of the external force generated by the wind load on the iron tower foundation.

Fig. 12 is a diagram showing a destruction method (Part 1) of the footing.

Fig. 13 is a diagram showing a destruction method (Part 2) of the footing.

Label description

1 pile

2 main piles

3 concrete structures

4. 4a～4c shear flange

5 steel pipes

6 concrete

7 support plate

8, 11 fixed rib

10 slope piles

12 connection beam

Detailed ways

Embodiments of the present invention will be described in detail below with reference to the drawings.

[first embodiment]

As shown in Fig. 1, the iron tower foundation structure of the present invention, when the many pile bodies 1, 1 ... that are driven into the foundation and the main pile column 2 of the iron tower are joined by the concrete structure body 3, as the above-mentioned concrete structure body 3, adopt A structure made by pouring concrete 6 into a steel pipe 5 having a plurality of shear flanges 4, 4 ... fixedly arranged along the circumferential direction on the inner wall surface in the vertical direction, and the lower part of the concrete structure 3 is jointed and drilled. Into the top of the multiple piles 1, 1... in the above foundation, and, on the outer surface of the lower part of the main pile column 2 of the above-mentioned iron tower, multi-section support plates 7, 7... are provided, and the main parts of the above-mentioned support plates 7, 7... are provided. The pile part K is embedded in the concrete structure 3 mentioned above.

More specific descriptions are given below.

As the concrete structure 3, for example, a thick-walled steel pipe having a diameter of about 1000 to 5000 mm and a thickness of about 20 to 30 mm is preferably used. The shear flanges 4, 4..., which are fixedly arranged on the inner wall surface, may have any cross-sectional shape as long as they are in the shape of protrusions that can reliably prevent slipping between the poured concrete 6. For example, as shown in Figure 5(A), the steel bar/steel bar 4a can be fixedly installed along the inner wall of the steel pipe 5 by welding, or as shown in Figure 5(B), using angle steel 4b, or as shown in Figure 5(C) Shown, utilize flat steel 4c etc.

In addition, in the illustrated example, a steel circular pipe is used as the above-mentioned steel pipe 5 , but steel pipes such as angular pipes and polygonal pipes may be used. In addition, the above-mentioned concrete structure 3 may be constructed by placing it on the ground, but it is preferable to construct it with most of it buried in the foundation in order to reduce displacement by earth pressure resistance.

As described above, since both the pressing force and the pulling force act on the main pile 2 due to the direction of the wind load, etc., in order to be able to cope with both the pressing force and the pulling force, the above-mentioned shear flange 4 is preferably The above-mentioned supporting plate arrangement part K of the iron tower main pile 2 is a boundary, and is respectively arranged on the upper side and the lower side thereof. Actually, it is preferable to arrange the steel pipes 5 at substantially equal intervals in the vertical direction.

The above-mentioned main pile 2 is provided with a plurality of stages, three stages of support plates 7, 7... in the illustrated example, and is embedded in the concrete structure so that the support plate arrangement position K is located in the approximate center of the above-mentioned concrete structure 3. Body 3. Although the cross-sectional dimension of the main pile 2 is not particularly limited, it is approximately 300 to 3000 mm. As the support plate 7, a ring-shaped plate is fixedly installed around the main pile 2 by welding or the like, but the planar shape of the support plate 7 may be a polygonal shape or the like. In addition, in the present embodiment, the support plate method is adopted as the fixing method of the above-mentioned main pile 2, but the anchor member fixing method shown in FIG. 7 may also be used.

And, in the illustrated example, the example of the steel pipe column has been shown as the main pile 2 of the iron tower, but as the main pile 2, for example, also can be triangular steel, and, also can make the main pile 2 as shown in Figure 4 The number is 2 to 4, and the combined columns 2' and the like connected by a plurality of diagonal rods 2a, 2a... are targeted.

The pile body 1 may be any of steel pipe piles, cast-in-place piles, and prefabricated piles, regardless of the type of the pile body. The diameter of the above-mentioned pile body 1 is desirably such that at least two or more, preferably about 4 to 6, can be evenly arranged in the above-mentioned steel pipe 5. It is a small-diameter pile below 1/6 of the above-mentioned steel pipe 5 diameter. The construction of the above-mentioned small-diameter piles can be carried out as follows: For example, after drilling holes in the foundation, insert steel pipes or prefabricated piles into the holes, fill the surrounding with solidified materials such as cement slurry or concrete, and high-fluidity concrete. It is also possible to insert vertical bars into the perforated holes and fill them with concrete or high-fluidity concrete to make cast-in-place piles. The perforation of the above-mentioned foundation can use a rotary type when the foundation is weak, and in the case of a foundation with a rock disk or a rock disk layer in the middle, it is preferable to use a rotary hammer type Dawnza Hole Hammer (trade name, hole impact hammer), etc. .

The above-mentioned pile body 1 and the concrete structure 3 are joined together in the example shown in the figure by arranging the fixing steel bars 8, 8... which straddle the two, but in the case of using steel pipe piles, it is also possible to adopt A supporting plate joining method in which the outer surface of the top of the pile in the concrete structure 3 is fixed by a ring-shaped supporting plate protruding outward.

The construction of the foundation structure detailed above is carried out as follows. First, foundation excavation is performed in the construction part of the concrete structure 3, steel pipes 5 are installed, and then piercing for the pile bodies 1, 1... is performed, and the pile bodies 1, 1... are driven into the foundation. Thereafter, the fixing ribs 8, 8... are set, and the base of the main pile 2 is positioned at a predetermined position in the steel pipe 5, fixed by a temporary fixing member (not shown), and the predetermined steel bars are arranged on the steel pipe Within 5, after all the reinforcement layout operations are completed, the concrete is poured.

[Second embodiment]

Next, the foundation structure of the second embodiment shown in FIG. 2 is provided with slope piles 10 driven obliquely downward from the peripheral wall portion of the steel pipe 5 of the concrete structure 3 . By providing the slope piles 10 integrally with the concrete structure 3, the press-fitting force is of course increased, but the pull-out resistance can also be further significantly improved. In addition, the above-mentioned slope pile 10 is only one in the illustrated example, and a plurality of them may be provided.

In the construction, the foundation excavation is first carried out in the construction part of the concrete structure 3, the wall surface of the excavation part is drilled, the slope pile 10 is driven in, and the steel pipe 5 is installed. In order to realize the integration with the above-mentioned slope pile 10, the insertion opening 5a of the fixing rib 11 is formed in advance in the wall surface of the steel pipe 5.

Next, perforation for the pile bodies 1, 1... is performed, and the pile bodies 1, 1... are set in the foundation. Thereafter, fixing ribs 8, 8... are provided, and the base of the main pile 2 is positioned at a predetermined position inside the steel pipe 5, fixed by a temporary fixing member (not shown), and predetermined reinforcing bars are arranged on the steel pipe 5. 5, and insert the fixing bar 11 from the insertion port 5a of the steel pipe 5, and pour concrete after all the reinforcing bar layout operations are completed.

In addition, concrete is also poured into the outer portion of the insertion port 5a of the steel pipe 5, and the top of the slope pile 10 is fixed to realize integration with the concrete structure 3.

[Third embodiment]

Secondly, the foundation structure of the third embodiment shown in FIG. 3 is provided with a connecting beam 12 between the concrete structures 3 and 3 of the main piles 2 of adjacent iron towers. The concrete structures 3, 3 are connected to each other by connecting beams 12, whereby the displacement of the foundation is largely suppressed.

The construction first excavates the foundation in the construction part of the concrete structure body 3, and horizontally perforates from the wall surface of the excavated part to form a through hole for setting the connecting beam 12, or in the shallow case, excavate the connecting beam through open excavation. Grooves are formed on the installation part, and the steel pipe 5 is installed after the connection beam 12 is installed. In addition, an insertion opening 5a for the fixing rib 11 is formed in advance on the wall surface of the steel pipe 5 in order to integrate with the above-mentioned connecting beam 12 .

Next, perforation for the pile bodies 1, 1... is performed, and the pile bodies 1, 1... are set in the foundation. Thereafter, fixing ribs 8, 8... are provided, and the base of the main pile 2 is positioned at a predetermined position inside the steel pipe 5, fixed by a temporary fixing member (not shown), and predetermined reinforcing bars are arranged on the steel pipe 5. 5, and insert the fixing bar 11 from the insertion port 5a of the steel pipe 5, and pour concrete after all the reinforcing bar layout operations are completed.

In addition, concrete is also poured on the outer portion of the insertion port 5a of the steel pipe 5 to fix the ends of the connecting beams 12 and integrate with the concrete structure 3 .

[the design of the fixation durability of this fixation method]

Next, the design method of the steel tower foundation of the present invention will be described.

In this design method, the failure mode (yield resistance of the steel pipe 5, adhesion resistance of the concrete around the support plate, and resistance of the shear flange 4) beyond the prevention of split failure is taken as the ultimate resistance, and a reasonable design is made.

The design of the fixing strength of this joining method can be carried out in consideration of the following matters, and can be designed according to the formula shown below.

(1) The yield strength f _pipe (stress) of the above-mentioned steel pipe 5 constraining concrete is determined by the following equation (1).

【Formula 1】

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; pipe</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; tan</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="l"\; filenames="C2005800295510017H1.png,C2005800295510018H1.png"\; state="\{\{state\}\}">l</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&le;</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; pipe</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; a</span>}}}{{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

f _{pipe_a} : allowable tensile stress of the restrained steel pipe

P: design vertical load

t: Constrained steel pipe wall thickness

l ₁ : fixed length (the interval between the uppermost section and the lowermost section of the support plate)

θ: The direction of the supporting force transmitted from the supporting plate to the concrete

γ ₁ : The strength reduction factor of steel pipes related to the construction conditions of shear resistance

γ _e : The coefficient related to the eccentricity caused by the construction error of the pile body

(2) The concrete adhesion resistance τ _b (stress) around the support plate 7 is determined by the following formula (2).

[Formula 2]

${\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="l"\; filenames="C2005800295510017H1.png,C2005800295510018H1.png"\; state="\{\{state\}\}">l</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; b</span>}}<span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

P: design vertical load

U _S : Attached shear perimeter around the support plate

l ₁ : fixed length (the interval between the uppermost section and the lowermost section of the support plate)

τ _ba : Allowable adhesion stress of concrete confined by steel pipes

(3) In order to discuss the resistance of the above-mentioned shear flange 4, the shear stress τ _sh of the welded part of the shear flange 4 is determined by the following formula (3).

[Formula 3]

${\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; sh</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; w</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&le;</span>\frac{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; sha</span>}}}{{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&kappa;</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

P: design vertical load

τ _sha : Allowable shear stress of the weld

n _rib : the number of shear-resistant roots

w: Weld leg length of welding part

D: Outer diameter of the steel pipe constrained

t: wall thickness of the steel tube to be restrained

γ ₂ : The strength reduction factor of the weld under the construction condition of shear resistance

κ: Coefficient of stress deviation considering shear resistance

(4) The supporting stress σ _c of the concrete in contact with the shear flange 4 is determined by the following formula (4).

[Formula 4]

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}}<span\; class="notranslate">\; \&le;</span>\frac{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; ca</span>}}}{\mathrm{<span\; class="notranslate">\; \&kappa;</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

P: design vertical load

σ _ca : allowable bearing stress of concrete

n _rib : the number of shear-resistant roots

D: Outer diameter of the steel pipe constrained

t: wall thickness of the steel pipe to be restrained

d _rib : the width of the shear resistance

α: additional factor for allowable bearing stress of biaxially restrained concrete

κ: Coefficient of stress deviation considering shear resistance

(5) The shear stress τ _{rib_c} of the concrete in contact with the inner periphery of the shear flange 4 is determined by the following formula (5).

[Formula 5]

${\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; ribs</span>}}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; b</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

P: design vertical load

τ _ba : Allowable adhesion stress of concrete bounded by steel pipes

D: Outer diameter of the steel pipe constrained

t: wall thickness of the steel pipe to be restrained

d _rib : the width of the shear resistance

l _rib : set width of shear resistance

Claims (7)

1. the base configuration of an iron tower, the many piles body that will squeeze in the ground by concrete body engages with the king pile post of iron tower, it is characterized in that,

Described concrete body is that concreting is gone in internal face has the steel pipe of the shearing resistance flange that multistage along the circumferential direction fixedly installs along the vertical direction and the structure of making, lower side at described concrete body engages the top of squeezing into the many piles body in the described ground, and the bottom at described iron tower king pile post is provided with fixed part, the king pile post that is provided with described fixed part partly is embedded in the described concrete body

If the diameter of described iron tower king pile post is φ, the configuration siding-to-siding block length of the base plate of described iron tower king pile post is L, when the internal diameter of described steel pipe is D, satisfies following condition: L/ φ=2～5, and D/ φ=2～10.

2. the base configuration of iron tower according to claim 1 is characterized in that,

Described many piles body is that bore is below the 400 φ mm or bore is the small-bore stake below 1/6 of described diameter of steel tube.

3. the base configuration of iron tower according to claim 1 and 2 is characterized in that,

Described shearing resistance flange is the border with the base plate configuration position of described iron tower king pile post, is located at its upper side and lower side respectively.

4. the base configuration of iron tower according to claim 1 and 2 is characterized in that,

The major part of described concrete body is embedded in the ground.

5. the base configuration of iron tower according to claim 1 and 2 is characterized in that,

Has the slope stake of squeezing into towards oblique direction down from the steel pipe surrounding wall portion of described concrete body.

6. the base configuration of iron tower according to claim 1 and 2 is characterized in that,

Have in conjunction with the tie-beam between the concrete body of described adjacent iron tower king pile post.

7. the base configuration of iron tower according to claim 1 and 2 is characterized in that,

The radical of described iron tower king pile post is 2 to 4.

Images