JPH02171473A - Construction of concrete silo with sheet steel hopper - Google Patents

Abstract

PURPOSE:To dispense with any instation of an excessive thick wall body as well as to aim at the effective utilization of a lower space by using a cylindrical strip steel sheet for attaching a lower discharge hopper to an inner surface, where a lot of studs are installed in many sides, as an inner form in combination. CONSTITUTION:A strip cylindrical steel sheet 1 for attaching a hopper 11 to an inner surface, having the same inner diameter as an inner diameter of a ferroconcrete erection wall 3 of a silo, and projectingly provided with a lot of studs 2 counting the number of pieces by a calculation formula on an outer surface is constituted. Next, each stud 2 is projected to the inner part from an inner end of arrangement of reinforcement of the erection wall 3, and an interval between a tip part and an outer circumferential surface of the erection wall 3 is set to be more than 30mm, adjusting the steel sheet 1 with mounting height of the hoper 11 and attaching it as a part of a form at the inside, and the erection wall 3 is placed, thus the hopper 11 is installed therein. Then, the silo is executed in a short construction period dispensing with any erection column or the like without giving any noncontinuity to the wall 3.

Description

[Detailed Description of the Invention] [Industrial Field of Application J The present invention relates to a silo that has an outer wall made of concrete and a bottom hopper made of a steel plate, and stores granular materials, etc., in which the hopper is integrally attached to the concrete wall, Concerning a method of constructing a concrete silo that can be fixed efficiently.

[Prior Art J] In a concrete silo storage facility in which the lower discharge hopper is made of a steel plate, a structure as shown in FIGS. 3 and 4 is known as a mounting structure for attaching a steel plate bottom to the silo. FIG. 3(a) is a vertical sectional view of the silo, and FIG. 3(b) is a plan view of the hopper mounting hardware.

FIG. 3 shows that the lower concrete of the vertical wall 12 is poured to the position of the hopper mounting bracket 15, and then the hopper mounting bracket 15, which has an L-shaped cross section and has a horizontal plate-like flange 14, is poured into the vertical wall 12. After installing on concrete, concrete for the upper vertical wall 13 is poured to construct a silo or the like. The hopper 11 is attached to the hopper attachment hardware 15. In this construction method, the upper and lower concrete walls 12 and 13 are separated at the flange 14, so it is necessary to construct a wall with an extra thickness due to the design.

FIG. 4 is a longitudinal sectional view of a silo showing another construction method.

In the method shown in FIG. 4, the support column 16 of the hopper 11 is erected regardless of the concrete wall 12. In this method, the hopper support hardware 17 becomes large, and the use of the space under the hopper, such as the installation of a gate, a tweeter, and a conveyor, is restricted by the support columns.

[Problem to be Solved by the Invention 1 The present invention has solved the above-mentioned drawbacks. The purpose of the present invention is to provide a method of constructing a concrete silo having a hopper made of steel plate.

[Means for Solving the Problems] The present invention provides a method for constructing a concrete silo having an erected cylindrical wall and a hopper made of a steel plate. , a cylindrical strip-shaped steel plate with a number of studs attached to its outer surface and a lower discharge hopper attached to its inner surface. (b) This cylindrical strip-shaped steel plate is attached as a formwork inside an erected cylindrical wall in accordance with the hopper installation height, and the concrete wall of the silo is poured.

(c) In this case, the studs must be firmly connected to the reinforced concrete of the standing wall and must be within the concrete cover. Therefore, the stud is made to protrude inward from the inner end of the reinforcement of the wall 3, and the distance between the tip of the stud and the outer peripheral surface of the standing wall is 30 mm or more.

[Function J: If a cylindrical strip-shaped steel plate with a large number of studs is installed in a predetermined position and the silo wall concrete is poured, this steel plate will serve as the inner formwork of the concrete and will be fixed integrally with the wall. Ru.

The number of studs can be determined by considering shear and tension.

[Embodiment 1] Fig. 1 shows an embodiment of the present invention, and is a longitudinal cross-sectional view of a silo wall in the vicinity of a hopper attachment part. In FIG. 1, a cylindrical steel plate 1 has a large number of studs 2 protruding from its outer surface, and a hopper 11 is attached to its inner surface. This cylindrical steel plate l is attached to the inner surface of the reinforced concrete standing wall 3 of the silo, and forms part of the formwork of the concrete standing wall 3. After the standing wall 3 is cast, the studs 2 are attached to the wall concrete. It is embedded as an anchor within the wall and is firmly connected to the reinforced concrete wall to become an integral part.

When the hopper 11 is attached to this cylindrical steel plate l, the wall concrete will not be separated by the hopper attachment hardware, and no support for the hopper is required.

Next, an example in which a concrete silo is constructed by attaching the steel plate 1 shown in FIG. 1 will be described. The number of studs 2 was determined as follows: 6 hopper lifting tensile stress T 2
= 76.54 as horizontal component H = T2 cos θ = 76.54 x cos 45” = 54.12 t/m Required number of studs: n Stud diameter: 16 mm ○ Allowable shear crab of bolt when receiving shear force qa Qa = φ5i (0, 5xscAr animals=T number)=0.4(
0.5x2.01 240x2. Ix105)=205
When receiving a tensile stress of 4 kg/crn' 0 As shown in FIG. 2, it is assumed that the stud 2 is supported by the cone-shaped concrete 4.

Pa1: Allowable tensile stress when determined by cone-shaped fracture of concrete Pa2: Allowable tensile stress when determined by yielding of bolt Pa3: Allowable tensile stress when determined by bearing pressure of concrete in contact with the head However, the bottom area of cone 4 Ac, allowable stress of steel soy,
Assuming the cross-sectional area of the steel material scA, the concrete strength Fc, and the pressure receiving surface LaAo of the stud head, 5in45' = 444crn' 5ay = 2.4 t/crr? 5cA=2.01crn" Fc =240kg/cm" 2.421 Ao= = 4.52c
m2, therefore =0.4r x 444 =2751kg/crn' Pa2: ψ2 ° s ay "scA=
x 2400 X2.01=
3216 Pa3=ψ3・fn −A.

x 2379 The number of studs Np is Pa2 Pal: φ15T - Ac The number n of bolts required for the composite stress is as follows.

. = 7 stones = 7 = 27. From 4 or more studs, the number of studs is 35 per 1 m of circumference. When tensile force and shear force are applied simultaneously, Figure 1 shows the concrete wall hopper of the embodiment of the present invention. A vertical cross-sectional view of the mounting portion, FIG. 2 is a partially enlarged view thereof, and FIGS. 3 and 4 are explanatory views of the prior art.

2... Stud 3... - Erected wall 4... Cone 11... Hopper = 0.30 +
0.32 = 0.62, which is smaller than 1, so this is fine.

〔Effect of the invention〕

According to the present invention, a cylindrical strip-shaped steel plate with studs attached is attached to also serve as the inner formwork of the erected wall of the silo, and the hopper is attached to this, so there is no discontinuity in the erected wall, and There is no need for a pillar below the hopper. Also,
It is possible to construct a highly reliable silo in a short construction period, and it is rational because it does not increase the amount of concrete.

[Brief explanation of the drawing]

Applicant Mitsubishi Mining Cement Co., Ltd. Agent
Patent Attorney Yoshio Kosugi [a] Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. When constructing a concrete silo having an upright cylindrical wall, a cylindrical strip having the same inner diameter as the inner diameter of the cylindrical wall, having a number of studs attached to its outer surface, and a lower discharge hopper attached to its inner surface. A hopper made of a steel plate is prepared, and the cylindrical strip-shaped steel plate is installed as a formwork inside an erected cylindrical wall according to the hopper installation height, and the concrete wall of the silo is poured. How to build a concrete silo. 2. The stud according to claim 1, wherein the stud projects inward from the inner end of the reinforcement of the erected cylindrical wall, and the distance between the tip of the stud and the outer peripheral surface of the erected cylindrical wall is 30 mm or more. A method of constructing a concrete silo with a steel plate hopper.