A method for determining the calculation length coefficient of the column of an elevator shaft working platform with a ladder without wall connection measures

Abstract

The present invention belongs to the field of civil engineering, and relates to a method for determining the calculated length coefficient of the columns of an elevator shaft work platform with a ladder without wall connection measures. It is characterized in that when the elevator shaft work platform is installed, it is connected to the ground at the opening of the elevator shaft through a card interface on one side of the mounting frame, and the side wall of the support platform opposite to the card interface is abutted against the inner wall of the elevator. Therefore, there will be a gap between the support platform and the inner wall of the elevator shaft. When operating, the work platform may shake, and the columns of the platform will have a certain lateral displacement in a certain direction. By analyzing the support conditions of the columns in different directions and the connection form of the upper and lower end beams, the formula for calculating the length coefficient of the column under pressure is derived, which provides a basis for the subsequent stability calculation of the columns.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering and relates to a method for determining a calculated length coefficient of a column of an elevator shaft working platform with a ladder without wall connection measures. Background Art

[0002] The elevator shaft operating platform is a standardized and detachable support platform for construction sites, which is specially used for elevator shaft construction. It can provide a safe and stable working environment, facilitate workers to carry out elevator shaft construction operations, and has the characteristics of fast installation, reusability, stability and durability. The platform material is made of high-strength steel, with good load-bearing capacity and earthquake resistance.

[0003] The elevator shaft operating platform is detachable and can be quickly assembled and disassembled according to the needs of the construction site without causing damage to the original building structure. This not only improves construction efficiency but also saves construction costs.

[0004] However, in the design of the elevator shaft work platform, how to ensure that the stable bearing capacity of its columns meets the requirements is a key issue in the design process. When installing the elevator shaft work platform, the card interface on one side of the mounting frame is connected to the ground at the opening of the elevator shaft, and the side wall of the support platform opposite to the card interface is abutted against the inner wall of the elevator, so that the support work platform is fixed in the elevator shaft as a whole. Therefore, there will be a gap between the support platform and the inner wall of the elevator shaft. When performing heavy-load operations such as wall reinforcement binding and formwork support on the work platform, the work platform may shake. During the shaking process, it will have a certain impact on the stability of the column and affect the calculated length of the column. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining the calculated length coefficient of the columns of an elevator shaft working platform with a ladder without wall connection measures, in view of the lateral displacement of the columns during use of the elevator shaft working platform, which may cause changes in the calculated length coefficient during stable calculation.

[0006] The present invention is achieved through the following technical solutions:

[0007] Step 1: According to equations (1) and (2), the calculated length coefficient μ of the column in the x-axis direction is obtained: x :

[0008]

[0009]

[0010] Where: μ xis the calculated length coefficient of the column in the x-axis direction (the same direction as the ladder rod), K1 is the sum of the linear stiffness of the beams intersecting the upper end of the column, K2 is the linear stiffness of the column, when the calculation is stable around the x-axis, α Nx is the beam line stiffness reduction factor, E is the elastic modulus, N b is the axial pressure on the beam, l is the length of the beam, I b is the moment of inertia of the beam section;

[0011] Step 2: According to equations (3) and (4), calculate the calculated length coefficient μ of the column in the y-axis direction: y :

[0012]

[0013]

[0014] Where: μ y is the calculated length coefficient of the column in the y-axis direction (perpendicular to the direction of the ladder rod), K3 is the sum of the stiffness of the beam lines intersecting the upper end of the column, and K4 is the sum of the stiffness of the beam lines intersecting the lower end of the column. When calculating the stability around the y-axis, α Ny is the beam linear stiffness reduction factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view of the model of the present invention;

[0016] Figure 2 It is a side view of a model of the present invention;

[0017] Figure 3 It is a top view of the model of the present invention.

[0018] In the figure: 1 main beam, 2 secondary beam, 3 hooks, 4 columns, 5 ladders, 6 bottom connecting parts, 7 diagonal braces. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and by way of embodiments.

[0020] Example

[0021] A construction site uses an elevator shaft work platform, whose columns are square steel pipe columns with a cross-sectional size of 50mm×50mm×3mm, a column height of 3000mm, and an elastic modulus E of 206000N / mm 2 The upper and lower crossbeams of the column are square steel pipe columns with lengths of 1500mm and 800mm, the axial force of the crossbeam is 5kN, and the moment of inertia of the crossbeam section is 208492mm 4 .

[0022] A method for determining a calculation length coefficient of a column of an elevator shaft working platform with a ladder without wall connection measures comprises the following steps:

[0023] Step 1: Obtain the calculated length coefficient μ of the column in the x-axis direction x :

[0024]

[0025]

[0026] μ x =0.608

[0027] Step 2: Obtain the calculated length coefficient μ of the column in the y-axis direction y :

[0028]

[0029]

[0030] μ y =1.160.

Claims

1. A method for determining the calculated length coefficient of the column of an elevator shaft working platform with a ladder without wall connection measures, characterized in that: The work platform moves sideways during use, and the calculated length of the column changes. The calculation method includes the following steps: Step 1: According to equations (1) and (2), the calculated length coefficient μ of the column in the x-axis direction is obtained: x : Where: μ x is the calculated length coefficient of the column in the x-axis direction which is the same as the direction of the ladder rod, K1 is the sum of the linear stiffness of the beams intersecting the upper end of the column, K2 is the linear stiffness of the column, when the calculation is stable around the x-axis, α Nx is the beam line stiffness reduction factor, E is the elastic modulus, N b is the axial pressure on the beam, l is the length of the beam, I b is the moment of inertia of the beam section; Step 2: According to equations (3) and (4), calculate the calculated length coefficient μ of the column in the y-axis direction: y : Where: μ y is the calculated length coefficient of the column in the y-axis direction perpendicular to the ladder rod direction, K3 is the sum of the stiffness of the beam lines intersecting the upper end of the column, and K4 is the sum of the stiffness of the beam lines intersecting the lower end of the column. When calculating the stability around the y-axis, α Ny is the beam linear stiffness reduction factor.

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