A test method for sliding friction coefficient of split heavy-load shifting device

Abstract

The present invention relates to a test method for the sliding friction coefficient of a split heavy-duty displacement device. Before the overall sliding construction of a larger structure, a proportional heavy-duty displacement device is constructed. After applying a vertical load until the pressure is stable, a horizontal pulling device applies a horizontal force, thereby causing the sliding device to slide horizontally, and recording its load size. The sliding friction coefficient during the actual operation is determined by the vertical force and the horizontal force. The heavy-duty displacement device is a split structure. The horizontal pulling device connects the fixed building and the sliding box to provide a horizontal force. The sliding box is placed above the slideway. A vertical lifting jack is arranged in the sliding box to provide a vertical force, and the sliding box can slide along the slideway to construct a friction surface. The vertical loading reaction frame is anchored on the ground trough by means of an anchoring screw. The pressure-bearing steel plate is placed on the top of the vertical lifting jack. A steel solid roller 6 is arranged between the pressure-bearing steel plate and the conversion beam to reduce the friction coefficient of the upper friction surface. The sliding friction coefficient test process is carried out in a laboratory with a ground trench and a reaction wall, simulating the actual construction process. The test obtains the sliding friction coefficient under the pulling and sliding working conditions, and then determines the specifications of the pulling or pushing and sliding equipment. It has a high degree of restoration and accuracy.

Description

Technical Field

[0001] The invention belongs to the field of construction, and in particular relates to a method for testing the sliding friction coefficient of a split heavy-load shifting device. Background Art

[0002] The coefficient of friction refers to the ratio of the friction force generated when two objects come into contact with each other to the pressure perpendicular to the contact surface. In the field of engineering, the magnitude of the coefficient of friction has an important impact on the design and operation of mechanical equipment. Therefore, it is very necessary to accurately measure the coefficient of friction. Common methods for measuring the coefficient of friction include the plate method, Newton ring method, and sliding method. The principle of the plate method is to place the object to be tested on a plate, and then apply a horizontal force to the object to start moving. By measuring the speed of the object and the force applied, the coefficient of friction can be calculated.

[0003] During the overall sliding construction of a larger structure, due to its large size and weight, it is necessary to determine the friction coefficient during the sliding process before formal construction on site, and then determine the specifications of the pulling or pushing sliding equipment. However, the size and material of the specific sliding structure will affect the results, and it cannot be detected by conventional methods, so targeted design is required. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a split heavy-load shifting device sliding friction coefficient testing device and a testing method thereof based on the pulling and sliding working conditions, which is convenient for determining the specifications of the sliding equipment in pulling or pushing construction.

[0005] A method for testing the sliding friction coefficient of a split heavy-load shifting device comprises the following steps:

[0006] Step 1: According to the processing details of the split heavy-load shifting device, make a 1:1 heavy-load shifting device, including a slide box and a slide groove. The friction surface is consistent with the actual project, and the MGB plate slides on the mirror stainless steel plate;

[0007] Step 2: Conduct a sliding friction coefficient test in a laboratory with a ground trough and a reaction wall. The reaction wall is used as a support for the horizontal traction jack, and the ground trough is used to anchor the reaction frame to provide vertical pressure load.

[0008] Step 3: Determine the top elevation of the test support track beam according to the height of the anchor hole of the reaction wall to ensure that after the slide box is installed, the center of the anchor hole of the fine-rolled threaded steel bar for horizontal traction and the center of the anchor hole of the reaction wall are on the same axis; determine the width of the test support track beam according to the width of the slide; at the same time, cast the support track beam with concrete of the same grade as the actual construction site to ensure that the friction surface of the slide and the concrete is consistent with the actual situation.

[0009] Step 4: After the concrete strength of the supporting track beam meets the requirements, install the various components of the vertical loading system, that is, hoist the slide chute, slide box, vertical support jack, pressure steel plate, rolling shaft, conversion beam, reaction frame on the supporting track beam in sequence, and anchor the reaction frame to the ground trough. Ensure the stability of each component during the hoisting process; during the hoisting process, the contact surface of the slide chute and the slide box should be fully coated with lubricating oil.

[0010] Step 5: After the vertical loading system is installed, install the horizontal traction device, including the horizontal traction fine-rolled threaded steel, the horizontal traction reaction beam, and the horizontal traction jack. A temporary shelving pier is set at the bottom of the horizontal traction reaction beam. The elevation of the pier top is determined according to the cross-sectional height of the horizontal traction reaction beam to ensure the axis elevation of the horizontal traction fine-rolled threaded steel. In the horizontal direction, the horizontal traction reaction beam is anchored to the reaction wall by a high-strength screw rod, and a gap is reserved between the horizontal traction reaction beam and the reaction wall. The gap should meet the requirements for the installation and tensioning of the horizontal traction jack.

[0011] Step 6: Preloading stage: Start the vertical support jack, load 50t vertically until the pressure is stable, and start the horizontal traction jack until the slide box slides 10mm relative to the slideway. After the preloading is completed, check whether there is relative sliding between the slideway and the supporting track beam, whether the conversion beam is overloaded or skewed, whether the rolling shaft between the pressure steel plate and the conversion beam is working normally, whether there is relative sliding between the horizontal traction reaction beam and the lower temporary shelving pier, and whether the horizontal traction fine-rolled threaded steel is horizontal.

[0012] Step 7: After the preloading is successfully implemented, after standing for 12 hours, the formal loading stage of friction coefficient measurement is carried out. First, start the vertical support jack for vertical loading, load the vertical pressure to 200t, and then start the horizontal traction jack for horizontal traction. The horizontal traction loading oil pump uses the oil pump actually used on site to ensure that the jack oil inlet rate is consistent with the site. Real-time record of the axial force value of the horizontal traction fine-rolled rebar.

[0013] Step 8: According to the axial force curve recorded in the formal loading stage, extract the axial force values ​​of the sliding box from the static state to the sliding state and the sliding box in the normal sliding process, and calculate the static friction coefficient of the sliding box from the static state to the sliding state and the dynamic friction coefficient of the sliding box in the normal sliding process. Here, since the rolling friction coefficient is very small, the rolling friction coefficient is not separated. The friction coefficient measured by this method is too large for the site and tends to be conservative.

[0014] Beneficial Effects

[0015] (1) The present invention tests the sliding friction coefficient by means of a split heavy-load displacement device in view of the characteristics of pulling or pushing sliding displacement of large buildings. The device is highly reproducible and targeted, and the test results have high accuracy.

[0016] (2) Through the test scheme of vertical loading and horizontal traction, the friction coefficient of the sliding friction surface is determined to provide a basis for the reasonable selection of traction equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of a split-type heavy-load shifting device sliding friction coefficient testing device used in the present invention;

[0018] Figure 2 yes Figure 1 A top view of

[0019] Figure 3 yes Figure 1 Right view of;

[0020] Figure 4 This is a physical picture of the slip-box.

[0021] Explanation of main figure marks: 1-bottom temporary support pier; 2-vertical tension anchor steel; 3-slide; 4-slide box; 5-vertical lifting jack; 6-steel solid roller; 7-conversion beam; 8-vertical loading reaction frame; 9-high-rolled threaded steel for horizontal pulling; 10-pressure-bearing steel plate; 11-jack for horizontal pulling; 12-horizontal traction reaction beam; 13-horizontal anchoring reaction frame; 14-vertical loading reaction frame anchor screw; 15-reaction wall; 16-ground trench; 17-long screw; 18-support track beam. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described in detail below in conjunction with specific embodiments:

[0023] Example 1

[0024] A method for testing the sliding friction coefficient of a split heavy-load shifting device comprises the following steps:

[0025] Step 1: According to the processing detailed drawing of the split heavy-load shifting device, a 1:1 heavy-load shifting device is made, including a slide box and a slide groove. The slide box 4 slides on the slide groove 3. The friction surface is consistent with the actual project. The bottom plate of the slide box 4 is an MGB plate, which slides on the mirror stainless steel plate of the slide groove 3 to construct the friction surface. During the hoisting process, the contact surface between the slide groove and the slide box is fully coated with lubricating oil;

[0026] Step 2: Conduct a sliding friction coefficient test in a laboratory with a ground trough 15 and a reaction wall 15, the reaction wall is used as a support for the horizontal traction jack 11, and the ground trough is used to anchor the vertical loading reaction frame 8 that provides a vertical pressure load.

[0027] Step 3: According to the height of the anchor hole of the reaction wall, determine the top elevation of the test support track beam 18 (control height h) to ensure that after the slide box is installed, the center of the anchor hole of the horizontal traction fine-rolled threaded steel 9 and the center of the anchor hole of the reaction wall are on the same axis; according to the width of the slide, determine the width of the test support track beam; at the same time, cast the support track beam with concrete of the same grade as the actual construction site to ensure that the friction surface of the slide and the concrete is consistent with the actual situation.

[0028] Step 4: After the concrete strength of the supporting track beam meets the requirements, install the various components of the vertical loading system, that is, hoist the slide 3, slide box 4, vertical lifting jack 5, pressure steel plate 10, steel solid roller 6, conversion beam 7, and vertical loading reaction frame 8 on the supporting track beam 8 in sequence. Two vertical reaction frames are arranged on the conversion beam 7. The crossbeam of the reaction frame is anchored to the ground trough through the anchor screw 14. The stability of each component is ensured during the hoisting process; the contact surface of the slide and the slide box should be fully coated with lubricating oil during the hoisting process. Among them, the vertical lifting jack 5 is placed in the slide box 4, and the number is determined according to the weight of the building to be moved; the pressure steel plate 10 is placed on the top of the vertical lifting jack 5, and a steel solid roller 6 is arranged between the pressure steel plate and the conversion beam.

[0029] The conversion beam 7 is fixed to the ground through the vertical loading reaction frame 8. In this process, in order to effectively simulate the friction coefficient between the pulley and the slideway, a steel solid roller 6 is arranged at the top of the lifting jack to reduce the friction coefficient of the upper friction surface.

[0030] Step 5: After the vertical loading system is installed, install the horizontal traction device, including the fine-rolled threaded steel bar 9 for horizontal traction, the horizontal traction reaction beam 12, and the horizontal traction jack 11. The fine-rolled threaded steel bar for horizontal traction connects the slide box and the horizontal traction jack 11, and the horizontal traction jack 11 applies horizontal force to the slide box. A temporary shelving pier 1 is set at the bottom of the horizontal traction reaction beam, and the elevation of the pier top is determined according to the cross-sectional height of the horizontal traction reaction beam to ensure the axis elevation of the fine-rolled threaded steel bar for horizontal traction. In the horizontal direction, the horizontal traction reaction beam is anchored to the reaction wall by a high-strength long screw 17, and a gap is reserved between the horizontal traction reaction beam and the reaction wall. The gap should meet the requirements for the installation and tensioning of the horizontal traction jack.

[0031] Step 6: Preloading stage: Start the vertical lifting jack 5, load 50t vertically until the pressure is stable, and then start the horizontal traction jack 11 until the slide box slides 10mm relative to the slideway. After the preloading is completed, check whether there is relative sliding between the slideway and the supporting track beam, whether the conversion beam is overloaded or skewed, whether the rolling shaft between the pressure steel plate and the conversion beam works normally, whether there is relative sliding between the horizontal traction reaction beam and the lower temporary shelving pier, and whether the horizontal traction fine-rolled threaded steel is horizontal.

[0032] Step 7: After the preloading is successfully implemented, after standing for 12 hours, the formal loading stage of friction coefficient measurement is carried out. First, start the vertical lifting jack for vertical loading, load the vertical pressure to 200t, and then start the horizontal traction jack for horizontal traction. The horizontal traction loading oil pump uses the oil pump actually used on site to ensure that the jack oil inlet rate is consistent with the site. Real-time record the axial force value of the horizontal traction fine-rolled threaded steel 9.

[0033] Step 8: According to the axial force curve recorded in the formal loading stage, extract the axial force values ​​of the sliding box from the static state to the sliding state and the sliding box in the normal sliding process state respectively. According to the formula f=μN The static friction coefficient of the sliding box from the static state to the sliding state and the dynamic friction coefficient of the sliding box during the normal sliding process are calculated respectively. The results are shown in Tables 1 and 2.

[0034] Among them, μ is the friction coefficient; f is the friction force, which is the resultant force of the horizontal traction jack; N is the vertical pressure and the resultant force of the vertical jack.

[0035] Table 1

[0036]

[0037] Table 2

[0038]

[0039] Here, the friction coefficient measured in this experiment did not deduct the rolling friction coefficient of the roller above the jack, but because the rolling friction coefficient is very small, the rolling friction coefficient is not separated. The friction coefficient measured by this method is too large for the site and is more conservative, with a higher safety reserve.

Claims

1. A method for testing the sliding friction coefficient of a split heavy-load displacement device, characterized in that: The following steps are involved: Step 1: Make a split heavy-duty shifting device for testing at a ratio of 1:

1. The friction surface and friction method are consistent with the actual project. The friction method is that the bottom plate of the sliding box of the split heavy-duty shifting device slides on the sliding groove; the friction surface is the contact surface between the bottom plate of the sliding box and the sliding groove; Step 2: Conduct a sliding friction coefficient test in a situation where there is a ground trough and a reaction wall. The reaction wall is used as a support for the horizontal traction jack, and the ground trough is used as an anchor for the vertical loading reaction frame that provides vertical pressure load; Step 3: Cast the supporting track beam and the temporary support pier at the bottom, and open anchor holes in the reaction wall; The horizontal traction device is placed on the temporary support pier, with one end fixed to the anchor hole of the reaction wall and the other end fixed to the side of the slide box of the split heavy-load shifting device; the slide slot of the split heavy-load shifting device is placed on the supporting track beam to ensure that the center of the horizontal traction device, the split heavy-load shifting device and the anchor hole of the reaction wall are on the same axis; The width of the supporting rail beam is the same as or slightly larger than the width of the chute, and the concrete grade of the supporting rail beam is the same as the actual one, ensuring that the friction surface between the chute and the concrete is consistent with the actual situation; Step 4: After the concrete strength of the supporting track beam meets the requirements, install the various components of the vertical loading system, that is, hoist the slideway, slide box, vertical support jack, pressure steel plate, rolling shaft, conversion beam, vertical loading reaction frame on the supporting track beam in sequence, and anchor the vertical loading reaction frame on the ground trough to ensure the stability of each component during the hoisting process; Step 5: After the vertical loading system is installed, install the horizontal traction device, including the horizontal traction fine rolled threaded steel bar, the horizontal traction reaction beam and the horizontal traction jack; the horizontal traction reaction beam is set on the temporary shelving pier cast in step 3, and the pier top elevation is determined according to the cross-sectional height of the horizontal traction reaction beam to ensure the axis elevation of the horizontal traction fine rolled threaded steel bar; in the horizontal direction, the horizontal traction reaction beam is anchored to the reaction wall by a high-strength screw rod, and a gap is reserved between the horizontal traction reaction beam and the reaction wall, which should meet the requirements for the installation and tensioning of the horizontal traction jack; Step 6: Preloading stage: Start the vertical lifting jack, apply vertical load until the pressure is stable, start the horizontal traction jack until the slide box slides slightly relative to the slide slot, and check the stability of the split heavy-load shifting device after the preloading is completed; Step 7: After the preloading is successfully implemented, let it stand until the whole system is stable, and then proceed to the formal loading stage of friction coefficient measurement; first start the vertical support jack for vertical loading, load the vertical pressure to the actual project estimated pressure value or the maximum allowable value of the vertical pressure under the premise of ensuring the safety and reliability of the trench force, then start the horizontal traction jack for horizontal traction, and record the axial force curve of the fine-rolled rebar for horizontal traction; Step 8: According to the axial force curve recorded in the formal loading stage in step 7, extract the axial force values ​​of the sliding box from the static state to the sliding state and the sliding box in the normal sliding process state respectively. According to the formula f=μN , calculate the static friction coefficient of the sliding box from the static state to the sliding state and the dynamic friction coefficient of the sliding box in the normal sliding process respectively; Among them, μ is the friction coefficient; f is the friction force, which is the resultant force of the horizontal traction jack; N is the resultant force of the vertical pressure and the vertical jack.

2. A method for testing the sliding friction coefficient of a split heavy-load shifting device according to claim 1, characterized in that: In step 1, the bottom plate of the slide box is an MGB plate, which slides on the mirror stainless steel plate of the slide groove; during the lifting process, the contact surface between the slide groove and the slide box is fully coated with lubricating oil, and the test result is the friction coefficient of the contact surface.

3. A method for testing the sliding friction coefficient of a split heavy-load shifting device according to claim 1, characterized in that: In step 4, the conversion beam is fixed to the ground through a vertical loading reaction frame; Vertical lifting jacks are placed in the skid box, and the number is determined by the load imposed by the building to be moved; The pressure-bearing steel plate is placed on the top of the vertical lifting jack, and a steel solid roller is arranged between the pressure-bearing steel plate and the conversion beam to reduce the friction coefficient of the upper friction surface.

4. A method for testing the sliding friction coefficient of a split heavy-load shifting device according to claim 1, characterized in that: In step six, after preloading is completed, the items to be checked include but are not limited to: whether there is relative sliding between the slide chute and the supporting track beam, whether the transfer beam is overloaded or skewed, whether the rolling shaft between the pressure steel plate and the transfer beam is working normally, whether there is relative sliding between the horizontal traction reaction beam and the lower temporary shelving pier, and whether the high-quality rolled threaded steel used for horizontal traction is level.

5. The method for testing the sliding friction coefficient of a split heavy-load displacement device according to claim 1, characterized in that: The horizontal traction loading oil pump adopts the oil pump actually used on site to ensure that the oil inlet rate of the jack is consistent with that on site.

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