Bailey truss monitoring method for squat silo roof construction

Abstract

The invention discloses a bailey truss monitoring and controlling method for squat silo roof construction, and belongs to the technical field of squat silo construction, and the method comprises the following steps: selecting a plurality of observation points on a bailey truss, binding a line weight which is 1m away from the ground on an upper chord girder of the bailey truss, arranging a 1.5 m steel pipe beside the line weight, driving the steel pipe into the ground by 0.4 m, and pasting 200mm scale paper on the top end; during observation, the right-angle side of the set square is aligned with the tip of the plummet, the scale paper is marked for reading, and the difference value is recorded as the settlement value. Observation is conducted for the first time before concrete pouring, and observation is conducted once every hour in the pouring process and within 2 hours after concrete pouring is completed. The maximum settlement value of each position is calculated according to the bailey truss structure, and an early warning value is set. According to the invention, by arranging a plurality of vertical bidirectional observation points and covering a key area, multi-dimensional data acquisition is realized, vertical settlement and horizontal displacement are monitored in real time, the monitoring precision is improved, and the construction safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of shallow silo construction, and particularly relates to a method for monitoring and controlling a Bailey truss during the construction of a shallow silo roof slab. Background Technique

[0002] During the concrete pouring construction of the shallow silo roof slab, the Bailey truss formwork support system, as a key support structure, its stability directly affects the construction safety and project quality. However, due to the continuous increase in load during the concrete pouring process and the elastic deformation characteristics of the Bailey truss itself, the formwork support system is prone to non-negligible settlement and displacement phenomena. In particular, significant deformations may occur at the mid-span and supports of the large beams due to local stress concentration. In traditional construction methods, limited to manual visual inspection or simple tools, it is difficult to capture dynamic displacements in real time; the correlation between the warning threshold setting and the change of construction load is insufficient, and the emergency measures for sudden settlement lack standardized procedures. These problems may lead to the failure to detect excessive settlement in a timely manner, and then trigger serious accidents such as the instability of the formwork support system, the cracking or even collapse of the concrete structure, resulting in construction delays and economic losses.

[0003] In the prior art, some improvement schemes attempt to improve the monitoring effect by increasing the monitoring frequency or introducing electronic sensors, but there are still the following defects: 1) The installation of sensors is complex and costly, and it is difficult to adapt to the complex construction site environment; 2) There is a lag in data collection and analysis, and it is impossible to provide immediate feedback for dynamic construction; 3) A hierarchical warning mechanism is not established in combination with the design parameters of the Bailey truss and the characteristics of load distribution, resulting in insufficient matching between the warning value and the actual bearing capacity; 4) The emergency response process is vague, and the specific disposal measures corresponding to the critical settlement value are not clear, affecting the risk control efficiency. Therefore, there is an urgent need to develop a Bailey truss settlement monitoring technology suitable for the construction of shallow silo roofs, by optimizing the layout of monitoring points, integrating multi-dimensional observation methods, establishing a scientific warning system and supporting standardized emergency procedures, so as to systematically improve the construction safety and controllability. Summary of the Invention

[0004] In view of this, the invention provides a method for monitoring and controlling a Bailey truss during the construction of a shallow silo roof slab to solve the above problems.

[0005] In order to achieve the above object, the invention adopts the following technical scheme:

[0006] A method for monitoring and controlling a Bailey truss during the construction of a shallow silo roof slab includes the following steps:

[0007] S1. Select multiple observation points on the Bailey truss and conduct settlement observations of the Bailey truss before and during the pouring of the roof slab concrete;

[0008] S2. Tie a plumb bob on the upper chord girder of the Bailey truss at the observation point, 1 m above the ground. Then, set up a 1.5-m-long steel pipe beside the plumb bob, drive it 0.4 m into the ground, and paste a 200-mm-long scale paper on the top of the steel pipe as the observation basis;

[0009] S3. During the observation, place the vertical right-angle side of the large triangular plate against the steel pipe, align the tip of the horizontal right-angle side with the tip of the plumb bob, draw a line and take a reading on the scale paper, make a record, and calculate the difference, which is the settlement value;

[0010] S4. Conduct the first observation of the original data before pouring the concrete. During the pouring process and within 2 hours after pouring, observe once every hour;

[0011] S5. Calculate the maximum settlement value at each position on the Bailey truss according to the structural design parameters and load distribution characteristics of the Bailey truss, and obtain the warning value for each position based on the maximum settlement value.

[0012] Further, in step S1, from a top-down perspective, the multiple observation points selected on the Bailey truss are in two perpendicular directions.

[0013] Further, in step S3, the vertical displacement of the plumb bob can also be measured using a level, and the horizontal displacement of the plumb bob can be measured using a total station.

[0014] Further, in step S5, the difference between the maximum settlement value and the warning value at each position on the Bailey truss is 5 mm.

[0015] Further, step S5 also includes the measures when the observation points on the Bailey truss reach the warning value:

[0016] S51. Immediately stop pouring the concrete and stop all loading activities; evacuate the personnel in a timely manner;

[0017] S52. Increase the observation frequency to once every half hour;

[0018] S53. If the settlement continues and the maximum settlement value reaches 50 mm, stop the observation, do not allow personnel to enter the bin, and cut off the power supply; continue the observation after the concrete has finally set;

[0019] S54. Before resuming construction, the acceptance team and relevant experts shall check the Bailey truss and carry out reinforcement before resuming construction.

[0020] The beneficial effects of the present invention are as follows:

[0021] By optimizing the layout of monitoring points, this invention sets multiple vertical two-way observation points to cover key areas. Combining the data collection of the plumb bob scale observation method or the levels and total stations, it can capture the vertical settlement value of the Bailey truss in real time, ensuring the comprehensiveness and accuracy of monitoring data, with the error control precision reaching the millimeter level. Based on the design parameters of the Bailey truss and the characteristics of the load distribution, the grading warning thresholds at various positions on the Bailey truss are differentiated to effectively match the actual bearing limit and avoid false alarms or missed alarms caused by traditional single thresholds. Through high-frequency and multi-dimensional data statistics, the safety of the construction of the shallow silo roof is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0023] Figure 1 It is a process flow chart of a monitoring and control method for the Bailey truss in the construction of the shallow silo roof.

[0024] Figure 2 It is a schematic diagram of the layout of the observation points on the Bailey truss. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] Referring to the attached Figure 1-2 , the present invention provides a monitoring and control method for the Bailey truss in the construction of the shallow silo roof, including:

[0027] S1. Select multiple observation points on the Bailey truss. From a top-down perspective, the multiple observation points are in two vertical directions. For example, Figure 2 , three observation points are respectively set in two vertical directions, located at the core tube, the mid-span point of the large beam, and the support of the Bailey truss, and then the settlement observation of the Bailey truss is carried out before and during the casting of the roof concrete.

[0028] S2. Tie a plumb bob to the upper chord large beam of the Bailey truss at the observation point, at a height of 1 m from the ground. Then, set up a steel pipe with a length of 1.5 m beside the plumb bob, drive it 0.4 m into the ground, and paste a scale paper with a length of 200 mm on the top of the steel pipe as the basis for observation.

[0029] S3. During observation, place the vertical right-angle side of the large triangular plate against the steel pipe, align the tip of the horizontal right-angle side with the tip of the plumb bob, draw a line on the scale paper and take readings, make records, and calculate the difference, which is the settlement value. It is also possible to use a level to measure the vertical displacement of the plumb bob and a total station to measure the horizontal displacement of the plumb bob.

[0030] S4. Conduct the first observation of the original data before pouring the concrete. During the pouring process and within 2 hours after pouring, observe once every hour.

[0031] S5. Based on the structural design parameters and load distribution characteristics of the Bailey truss, calculate the maximum settlement value at each position on the Bailey truss, and obtain the warning value at each position based on the maximum settlement value. The difference between the maximum settlement value and the warning value at each position on the Bailey truss is 5 mm. For example, the maximum settlement value at the core tube and the mid-span of the main beam of the Bailey truss can reach 35 mm, and the maximum settlement value at the support of the main beam can reach 15 mm. Therefore, the alarm value for the observation points at the core tube and the mid-span of the main beam is set at 30 mm, and the alarm value for the observation points at the support is set at 10 mm.

[0032] Based on the set warning values for each observation point, the measures when each observation point on the Bailey truss reaches the warning value are as follows:

[0033] S51. Immediately stop pouring the concrete, stop all loading activities, and promptly evacuate the personnel.

[0034] S52. Increase the observation frequency to once every half hour.

[0035] S53. If the settlement continues and the maximum settlement value reaches 50 mm, stop the observation, prohibit personnel from entering the bin, and cut off the power supply. Continue the observation after the concrete has set.

[0036] S54. Before resuming construction, the acceptance team and relevant experts shall inspect the Bailey truss and carry out reinforcement before continuing the construction.

[0037] The above are only specific embodiments of the present invention. Common general knowledge such as specific structures and characteristics in the solution is not described in detail here. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application shall be subject to the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

[0038] In the present specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For related parts, reference can be made to the description in the method section.

[0039] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A monitoring method for Bailey trusses in the construction of the top plate of a shallow silo, characterized in that, It includes the following steps: S1. Select multiple observation points on the Bailey truss and conduct settlement observations of the Bailey truss before and during the casting of the top slab concrete. S2. Tie a plumb bob to the upper chord girder of the Bailey truss at the observation point, with a height of 1 m from the ground. Then, set up a steel pipe with a length of 1.5 m beside the plumb bob, drive it 0.4 m into the ground, and paste a scale paper with a length of 200 mm on the top of the steel pipe as the observation basis. S3. During observation, place the vertical right-angle side of a large triangular plate against the steel pipe, align the tip of the horizontal right-angle side with the tip of the plumb bob, draw a line and take a reading on the scale paper, make a record, and calculate the difference as the settlement value. S4. Conduct the first observation of the original data before casting the concrete, and observe once every hour during the casting process and within 2 hours after the casting is completed. S5. Calculate the maximum settlement value at each position on the Bailey truss according to the structural design parameters and load distribution characteristics of the Bailey truss, and obtain the warning value at each position based on the maximum settlement value.

2. The monitoring and control method of the Bailey truss for the construction of the top plate of a shallow silo according to claim 1, wherein, In step S1, from a top-down perspective, multiple observation points selected on the Bailey truss are in two perpendicular directions.

3. The monitoring and control method of the Bailey truss for the construction of the shallow silo roof according to claim 1, characterized in that, In step S3, a level can also be used to measure the vertical displacement of the plumb bob, and a total station can be used to measure the horizontal displacement of the plumb bob.

4. A monitoring and control method for a Bailey truss in the construction of the top plate of a shallow silo according to claim 1, characterized in that, In step S5, the difference between the maximum settlement value and the warning value at each position on the Bailey truss is 5 mm.

5. A monitoring method for a Bailey truss in the construction of the top plate of a shallow silo according to claim 1, characterized in that, Step S5 also includes measures when the observation points on the Bailey truss reach the warning value: S51. Immediately stop the concrete casting and all loading activities; promptly evacuate the personnel. S52. Increase the observation frequency to once every half hour. S53. If the settlement continues and the maximum settlement value reaches 50 mm, stop the observation, prohibit personnel from entering the bin, and cut off the power supply; continue the observation after the concrete has finally set. S54. Before resuming construction, the acceptance team and relevant experts shall inspect the Bailey truss and carry out reinforcement before resuming construction.

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