Formwork side pressure monitoring method in secondary lining concrete pouring process

Abstract

The invention provides a method for monitoring the side pressure of a formwork in the secondary lining concrete pouring process, and relates to the technical field of formwork pressure monitoring. By calculating the strength increasing rate of concrete, the actual strength change of the concrete in the pouring process can be reflected more accurately when the side pressure of the formwork is calculated; by analyzing the environment temperature and humidity of a pouring site, an environment influence correction coefficient is calculated, so that side pressure correction of the formwork not only depends on internal data in the pouring process, but also can adapt to dynamic changes of the external environment, the stress state of a supporting system is evaluated in real time, and the supporting system can be accurately and accurately corrected in combination with plate parameters of the formwork. The comprehensive bearing capacity data of the template supporting system can be generated, the comprehensive bearing capacity data is combined with the corrected template side pressure data, the safety coefficient is calculated, the safety coefficient is compared with the preset safety threshold value, and the safety of the template supporting system is judged in time.

Description

Technical Field

[0001] The invention relates to the technical field of formwork pressure monitoring, and in particular to a method for monitoring the side pressure of a formwork during the pouring of secondary lining concrete. Background Art

[0002] During the construction of large-volume concrete structures in tunnels, the pouring of secondary lining concrete is a very critical process. Secondary lining concrete refers to the formation of the final structural cross-section by pouring concrete again after the initial support structure is completed, in order to ensure the structural stability, durability and waterproofness of the tunnel or underground project. In this process, the formwork is used to fix and shape concrete, so the lateral pressure monitoring of the formwork is crucial to the safety of the project. As the concrete is gradually poured, factors such as the gravity of the concrete and changes in internal temperature and humidity will continuously increase the lateral pressure of the formwork. If this lateral pressure cannot be effectively monitored and controlled, it may cause deformation of the formwork or failure of the support system, leading to collapse or serious safety accidents. Therefore, how to accurately monitor and adjust the lateral pressure of the formwork during the pouring process is a technical problem that needs to be solved during the construction process.

[0003] At present, the monitoring methods for the side pressure of the formwork in the prior art usually adopt static monitoring means. Common methods include calculating the side pressure based on empirical formulas, or recording the stress conditions of the formwork during the pouring process by installing strain sensors and pressure sensors on the formwork. These data are usually calculated based on parameters such as concrete height, density, and pouring rate, and the side pressure is estimated based on existing engineering experience. In some cases, the influence of external conditions such as temperature and humidity in the construction environment on the strength of concrete is also considered to correct the side pressure. However, although these methods can provide a certain reference for the stress state of the formwork, they mainly rely on static data and fail to fully consider the dynamic changes in concrete strength and the complexity of the real-time construction environment.

[0004] The deficiencies of existing technologies are mainly reflected in three aspects. First, the traditional method fails to reflect the strength growth process of concrete in real time, resulting in inaccurate calculation of lateral pressure, especially during long-term pouring, the strength increase of concrete cannot be taken into account in a timely manner. Secondly, the existing formwork side pressure monitoring methods are not sensitive to dynamic changes in the external environment, such as the impact of temperature and humidity changes on the solidification rate of concrete, and fail to fully integrate environmental data to correct the lateral pressure. Finally, the traditional method lacks monitoring of the dynamic load effects of the support system, and cannot effectively evaluate the complex stress state of the formwork support system during the actual pouring process, resulting in lag and inaccuracy in the judgment of the safety of the support system.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0006] The object of the present invention is to provide a method for monitoring the pressure on the side of the formwork during the pouring of secondary lining concrete, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for monitoring the pressure on the side of the formwork during the pouring of secondary lining concrete, the specific steps comprising:

[0009] Step 1: Real-time collection of internal environmental data of poured concrete, concrete gravity density and pouring height data, wherein the internal environmental data includes internal temperature and internal humidity data, and the strength growth rate of concrete is calculated through the internal environmental data, and the lateral pressure of the formwork is obtained through the concrete gravity density and pouring height data;

[0010] Step 2: Collect external environmental data of the pouring site, the external environmental data including ambient temperature and ambient humidity data of the pouring site, analyze the external environmental data to obtain an environmental impact correction coefficient, use the strength growth rate and the environmental impact correction coefficient to correct the lateral pressure of the formwork, and obtain the corrected lateral pressure data of the formwork;

[0011] Step 3: Collect the pressure parameters of the connection points of the formwork support unit, number each connection point, analyze the pressure parameters of each connection point, and generate the dynamic load effect index of the support system. The support unit includes support columns, beams and diagonal braces, and the pressure parameters include stress and strain data.

[0012] Step 4: Obtain the parameters of each supporting column, each beam and each diagonal brace, and collect the plate parameters of the template, which include the thickness and area of ​​the template, the bending strength data of the template material and the support span. Combine the acquired parameters and the plate parameters to build an analysis model to generate the comprehensive bearing capacity data of the template support system;

[0013] Step 5: Add the corrected lateral pressure data of the formwork and the dynamic load effect index to obtain the total lateral pressure. Generate a safety factor based on the total lateral pressure and the comprehensive bearing capacity data. Compare the safety factor with the safety threshold to determine the safety of the formwork support system.

[0014] Furthermore, the strength growth rate of concrete is calculated by internal environmental data as follows:

[0015] According to the thickness of the poured concrete, multiple sets of internal temperature data and internal humidity data of different thickness areas are collected at equal thickness intervals, and analyzed to obtain the strength growth rate. The formula is:

[0016]

[0017] Among them, R q represents the intensity growth rate, T0 and H0 are standard temperature data and standard humidity data respectively, R0 is the intensity growth rate under standard temperature and standard humidity, α and β are temperature empirical coefficient and humidity empirical coefficient respectively, α>β>0 and α+β=1, N represents the total number of groups of internal temperature data and internal humidity data collected, T i and H i Respectively represent the i-th group of internal temperature data and internal humidity data.

[0018] Furthermore, the environmental impact correction coefficient obtained by analyzing the external environmental data is as follows:

[0019] According to the height of concrete pouring, collect multiple sets of ambient temperature and humidity data on the template surface at equal height intervals on the side of the template, and calculate the environmental impact correction coefficient based on the formula:

[0020]

[0021] Among them, R e represents the environmental impact correction coefficient, M represents the total number of sets of collected ambient temperature and ambient humidity data, Te j 、He j They respectively represent the ambient temperature and ambient humidity data of the jth group of template surfaces.

[0022] Furthermore, the lateral pressure of the formwork is obtained by the gravity density of concrete and the pouring height data as follows:

[0023] Determine the gravity density of concrete based on the concrete mix ratio, measure the height of concrete pouring, combine the gravity density of concrete and the height of concrete pouring, and calculate the lateral pressure of the formwork based on the formula:

[0024] P0=γ c *h

[0025] Among them, P0 represents the lateral pressure of the template, γ c represents the gravity density of concrete, and h represents the height of concrete pouring.

[0026] Furthermore, the specific formula for correcting the side pressure of the template is:

[0027] P x =P0*(1-k*Rq ) / R e

[0028] Among them, P x Represents the side pressure data of the modified template, R e Represents the environmental impact correction factor, R q represents the strength growth rate, k represents the adjustment coefficient, and the value range of the adjustment coefficient is: 0.01≤k≤0.03.

[0029] Furthermore, the connection of the formwork support unit includes the connection between the support column and the beam, the connection between the support column and the diagonal brace, and the connection between the beam and the diagonal brace. The method for generating the dynamic load effect index of the support system is:

[0030]

[0031] Among them, E d represents the dynamic load effect index, S p and ∈ p They represent the stress and strain data of the connection numbered p, respectively, and P represents the total number of connections.

[0032] Furthermore, the inherent parameters of the support column include the cross-sectional area of ​​the support column and the compressive strength data of the support column material, the inherent parameters of the beam include the yield strength of the beam material, the width, height, support span and safety factor of the beam, and the inherent parameters of the diagonal brace include the cross-sectional area of ​​the diagonal brace and the compressive strength of the diagonal brace material.

[0033] Furthermore, the specific method for generating the comprehensive bearing capacity data of the formwork support system is as follows:

[0034] The cross-sectional area of ​​each support column and the compressive strength data of the support column material are multiplied to obtain the bearing capacity data of each support column, and the bearing capacity data of all support columns are summed to obtain the total bearing capacity data of the support columns;

[0035] The cross-sectional area of ​​each brace is multiplied by the compressive strength of the brace material to obtain the bearing capacity data of each brace, and the bearing capacity data of all braces are summed to obtain the total bearing capacity data of the braces;

[0036] The load-bearing capacity of each beam is calculated based on the yield strength of the beam material, the width, height, support span and safety factor of the beam. The formula used is:

[0037]

[0038] Among them, Hl ρ represents the load-bearing capacity of the ρth beam, HFy ρ represents the yield strength of the material of the ρth beam, b ρ,Hh ρ , L ρ and γ ρ They represent the width, height, support span and safety factor of the ρth beam material respectively. ρ represents the beam number, ρ = 1, 2, ..., Hl N , Hl N is the total number of beams, and the safety factor of the beam is the ratio between the ultimate load-bearing capacity of the beam and the design load;

[0039] The total bearing capacity data of the beams is generated by superimposing the bearing capacity data of all beams, and the bearing capacity data of the template is generated according to the plate parameters of the template. The formula is:

[0040]

[0041] Among them, Mb z Indicates the bearing capacity data of the template, Mh and A represent the thickness and area of ​​the plate respectively, Mf p It represents the bending strength of the formwork material, and Mk represents the support span of the formwork;

[0042] Based on the total bearing capacity data of supporting columns, diagonal braces, beams and the bearing capacity data of the formwork, the comprehensive bearing capacity data of the formwork support system is generated according to the following method:

[0043]

[0044] Among them, Zh c Represents the comprehensive bearing capacity data of the formwork support system, Zc z 、Xc z and Hl z They respectively represent the total bearing capacity data of the supporting column, the diagonal brace and the cross beam, θ1, θ2 and θ3 respectively represent the first weight coefficient, the second weight coefficient and the third weight coefficient, and 2>θ1>1>θ2>θ3≥0.5.

[0045] Furthermore, the safety factor generated according to the total lateral pressure and comprehensive bearing capacity data is as follows:

[0046]

[0047] Among them, Z cy Indicates the total side pressure, P x Indicates the side pressure data of the modified template, E d The dynamic load effect index SF represents the safety factor. If SF<SF y If the support is insufficient, an early warning will be issued; otherwise, no early warning will be issued. y Indicates the safety threshold.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention collects the internal temperature and humidity of the poured concrete, the gravity density of the concrete and the pouring height in real time, calculates the strength growth rate of the concrete in real time, so that the calculation of the lateral pressure of the template can more accurately reflect the actual strength change of the concrete during the pouring process, avoiding the static assumption and delayed response in the traditional method; by analyzing the ambient temperature and humidity at the pouring site, the environmental impact correction coefficient is calculated, so that the lateral pressure correction of the template not only depends on the internal data during the pouring process, but also can adapt to the dynamic changes of the external environment, thereby providing a more accurate lateral pressure evaluation. By considering internal and external environmental factors, the present invention makes the monitoring results more credible and can better reflect the mechanical state of the model under actual construction conditions;

[0050] The present invention performs numbering and pressure monitoring on the joints of components such as support columns, beams, and diagonal braces, evaluates the stress state of the support system in real time, and constructs a more comprehensive load-bearing capacity analysis model. Combined with the plate parameters of the formwork, it can generate comprehensive load-bearing capacity data of the formwork support system, thereby making the calculation of the safety factor more comprehensive and accurate. The comprehensive load-bearing capacity data is combined with the corrected formwork side pressure data to calculate the safety factor, and the safety factor is compared with a preset safety threshold to timely judge the safety of the formwork support system. The present invention significantly improves the safety monitoring capability and construction reliability during the pouring of the secondary lining concrete through real-time data collection, dynamic analysis and correction, and comprehensive load-bearing capacity evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0053] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] Example:

[0055] See also Figure 1 , the present invention provides a technical solution:

[0056] A method for monitoring the pressure on the side of the formwork during the pouring of secondary lining concrete, the specific steps comprising:

[0057] Step 1: Collect the internal environment data of the poured concrete, the gravity density of the concrete and the pouring height data in real time. The internal environment data includes the internal temperature and internal humidity data. The strength growth rate of the concrete is calculated through the internal environment data. The lateral pressure of the formwork is obtained through the gravity density of the concrete and the pouring height data.

[0058] In this embodiment, the strength growth rate of concrete is calculated by internal environment data as follows:

[0059] According to the thickness of the poured concrete, multiple sets of internal temperature data and internal humidity data of different thickness areas are collected at equal thickness intervals, and analyzed to obtain the strength growth rate. The formula is:

[0060]

[0061] Among them, R q represents the intensity growth rate, T0 and H0 are standard temperature data and standard humidity data respectively, R0 is the intensity growth rate under standard temperature and standard humidity, α and β are temperature empirical coefficient and humidity empirical coefficient respectively, α>β>0 and α+β=1, N represents the total number of groups of internal temperature data and internal humidity data collected, T i and H i Respectively represent the i-th group of internal temperature data and internal humidity data.

[0062] Collecting multiple sets of internal temperature data and internal humidity data at different thicknesses at equal thickness intervals means selecting several locations that are equidistant from the surface of the concrete to the other side. For example, if the total thickness of the concrete is 100 cm, you may choose to collect data every 10 cm. Therefore, you will collect data at depths of 0 cm, 10 cm, 20 cm, and up to 100 cm, and collect temperature and humidity data at these different thicknesses. The temperature and humidity data at each depth point form a group, so the data collected from multiple depths are grouped together. This collection method ensures that we can obtain the temperature and humidity changes of the concrete from the surface to different depths inside. Since the temperature and humidity inside the concrete may change due to factors such as materials, ambient temperature, and chemical reactions during the pouring process, collecting data at different thicknesses can provide comprehensive internal environmental information.

[0063] The strength growth of concrete is related to the hydration reaction of cement, and the reaction rate is significantly affected by temperature and humidity. Temperature increase usually accelerates the hydration reaction, thereby accelerating the strength growth; humidity affects the water retention inside the concrete, and too low humidity will lead to insufficient hydration reaction. This implementation averages the collected temperature and humidity data to eliminate the randomness of individual data points and obtain a more stable and representative average value, which is then standardized, that is, divided by the standard temperature and standard humidity to establish a benchmark condition. This standardization allows data under different construction conditions to be effectively compared. The standard temperature is 20 degrees Celsius, because 20 degrees Celsius is considered to be a temperature suitable for most hydration reactions and can provide a relatively stable and repeatable test environment. The standard humidity is 100%, and 100% humidity can ensure maximum hydration reaction. The strength growth rate under standard conditions is usually obtained through laboratory tests. In the laboratory, concrete samples are cured under controlled temperature and humidity, and their compressive strength is tested regularly. A curve of concrete strength over time can be drawn to determine the strength growth rate under standard conditions.

[0064] The strength growth rate reflects the speed at which the compressive strength of concrete increases over time within a specific time interval. If the strength growth rate is fast, the concrete enters the hardening stage earlier and the lateral pressure decreases faster. On the contrary, if the strength growth rate is slow, the concrete maintains a high fluidity for a long time, and the lateral pressure of the formwork will last for a long time.

[0065] Humidity affects the transfer of water between cement particles, which in turn affects the hydration reaction. Although humidity changes will affect the reaction environment, its direct effect on the reaction rate is not as significant as temperature. The hydration reaction tends to be completed under high humidity, but after the humidity reaches a certain level, its additional effect on strength growth tends to weaken. Therefore, an exponential form is used to reflect the nonlinear effect of temperature and humidity on strength growth. The effect of temperature on strength growth is greater, while the effect of humidity is relatively weak. Therefore,

[0066] α>β>0, α+β=1 means that the influence of temperature and humidity is limited in the total intensity growth rate, that is, the sum of the influence weights of the two is 1.

[0067] Step 2: Collect external environmental data of the pouring site, wherein the external environmental data includes the ambient temperature and ambient humidity data of the pouring site, analyze the external environmental data to obtain the environmental impact correction coefficient, use the strength growth rate and the environmental impact correction coefficient to correct the lateral pressure of the formwork, and obtain the corrected lateral pressure data of the formwork.

[0068] The environmental impact correction coefficient obtained by analyzing the external environmental data is as follows:

[0069] According to the height of concrete pouring, collect multiple sets of ambient temperature and humidity data on the template surface at equal height intervals on the side of the template, and calculate the environmental impact correction coefficient based on the formula:

[0070]

[0071] Among them, R e represents the environmental impact correction coefficient, M represents the total number of sets of collected ambient temperature and ambient humidity data, Te j 、He j They respectively represent the ambient temperature and ambient humidity data of the jth group of template surfaces.

[0072] During the concrete construction process, concrete is usually poured in layers, especially in the concrete pouring of tall structures. The pouring height refers to the vertical distance from the bottom of the formwork to the top of the current pouring layer. Equal-height interval collection is to collect data at a certain vertical interval on the side of the formwork. Specifically, according to the height of concrete pouring, multiple height points are selected at certain intervals (such as every 1 meter, 2 meters, etc.), and measurements are taken at these points. At each selected height point, instruments such as thermometers and hygrometers are used to record the ambient temperature and humidity of the formwork surface. During the pouring process of concrete at different heights, it may be affected by different temperatures and humidity. The environmental conditions at different heights may be different. Understanding these differences and calculating the average value will help to better evaluate the hydration and strength development of concrete.

[0073] The environmental impact correction factor specifically reflects the effect of the temperature and humidity of the external environment on the strength growth of concrete and the side pressure of the formwork. Under high temperature conditions, concrete will gain strength quickly in the early stage after pouring, thereby reducing the side pressure demand on the formwork during this period. Under low temperature conditions, the strength growth is slow, and the formwork needs to withstand high side pressure for a longer period of time, resulting in a delayed peak in the side pressure. Ambient humidity affects the curing conditions and water loss rate of concrete. Higher ambient humidity helps prevent the concrete surface from losing water too quickly, thereby maintaining the necessary hydration environment and ensuring that the concrete strength grows as expected. Lower humidity may cause the concrete surface to dry out prematurely, affecting the ultimate strength and durability.

[0074] This embodiment calculates the deviation between the average value of the current ambient temperature and humidity and the reference value. A positive deviation means that the ambient conditions are more conducive to the growth of concrete strength than the reference, which may lead to a smaller side pressure requirement. A negative deviation is the opposite. The effects of temperature and humidity are weighted and linearly superimposed in the formula, reflecting their independent effects on concrete performance. Different ambient conditions will correct the pressure calculation through the correction coefficient. By converting the ambient deviation into a correction factor and multiplying it by the uncorrected template side pressure, a pressure value that is more in line with the actual ambient conditions can be obtained.

[0075] If the value of the environmental impact correction coefficient is greater than 1, it means that the current environmental conditions have a positive impact on strength growth (i.e., it helps to improve strength). If it is less than 1, it means that the environmental conditions may inhibit strength growth. If the average ambient temperature of the formwork surface is higher than the standard temperature, it means that higher temperatures help accelerate the hydration reaction of cement, thereby promoting strength growth. If the average ambient humidity of the formwork surface is higher than the standard humidity, it means that under conditions of high humidity, the moisture on the concrete surface is well maintained, which helps the hydration reaction to continue, thereby promoting strength growth.

[0076] The lateral pressure of the formwork is obtained by the gravity density of concrete and the pouring height data as follows:

[0077] Determine the gravity density of concrete based on the concrete mix ratio, measure the height of concrete pouring, combine the gravity density of concrete and the height of concrete pouring, and calculate the lateral pressure of the formwork based on the formula:

[0078] P0=γ c *h

[0079] Among them, P0 represents the lateral pressure of the template, γ c represents the gravity density of concrete, and h represents the height of concrete pouring.

[0080] The gravity density of concrete refers to the mass of concrete per unit volume. The calculation of gravity density is generally determined based on its mix ratio (i.e. the ratio of cement, sand, stone, admixture and water). The pouring height refers to the vertical distance from the bottom of the concrete formwork to the top of the current pouring layer. The concrete exerts lateral pressure on the formwork due to its weight. The gravity density and height jointly determine the magnitude of this pressure.

[0081] The specific formula for correcting the side pressure of the template is:

[0082] P x =P0*(1-k*R q ) / R e

[0083] Among them, P x Represents the side pressure data of the modified template, R e Represents the environmental impact correction factor, R q represents the strength growth rate, k represents the adjustment coefficient, and the value range of the adjustment coefficient is: 0.01≤k≤0.03.

[0084] The lateral pressure of concrete is a dynamic process, which is affected by many factors such as the growth of concrete strength and changes in environmental conditions. The calculation of the lateral pressure of the formwork can only preliminarily calculate the pressure exerted on the formwork by the concrete in the uncured state, but it only considers the gravity density and pouring height of the concrete, and does not consider the strength growth of the concrete during the hardening process and the influence of the external environment on the pressure. The strength of concrete is not constant, but gradually increases over time. The greater the growth rate of strength means that the concrete gradually becomes stronger, and the contribution to the lateral pressure decreases accordingly.

[0085] P x It is the correction of the calculated pressure P0. This correction involves two factors: the strength growth rate and the environmental influence correction factor, which is calculated by 1-k*R q This term takes into account the effect of the strength growth rate on the lateral pressure. If the strength growth rate R q If the strength is larger, the lateral pressure on the formwork should be reduced accordingly, because the increase in strength means that the concrete can better resist external pressure. Here R q The larger the value, 1-k*R q The smaller the value, the smaller the lateral pressure P x becomes smaller, reflecting the inhibitory effect of strength improvement on lateral pressure. Because the higher the strength, the stronger the bearing capacity of concrete, and the lateral pressure on the formwork should be reduced accordingly. e The larger the value, i.e. when the environmental conditions are favorable), the corrected side pressure P x will decrease, reflecting that the concrete hardens faster and the lateral pressure decreases due to the favorable environment.

[0086] The function of the adjustment coefficient k is to correct the influence of the concrete strength growth rate on the side pressure when calculating the side pressure of the formwork. The adjustment coefficient k is an empirical parameter used to adjust the influence of the strength growth rate on the side pressure of the formwork.

[0087] The value of k determines the effect of the strength growth rate on reducing the lateral pressure. If k is too large, then even if the strength growth rate is small, the lateral pressure of the formwork will be excessively reduced, which may not conform to the actual situation; if k is too small, even if the strength growth rate is large, the effect of reducing the lateral pressure will be ignored.

[0088] The adjustment coefficient k is determined by experimental data or engineering experience, rather than by direct calculation. It depends on the following factors: different types of concrete materials may react differently to lateral pressure during strength growth, so the k value should be adjusted according to the specific material properties. Construction conditions such as formwork setting, concrete pouring speed, ambient temperature and humidity will affect the actual performance of concrete strength growth rate, thereby affecting the k value. The range of the adjustment coefficient k is derived from a large amount of engineering experience and repeatedly verified under specific construction environments and material conditions.

[0089] The function of the adjustment coefficient k is to adjust the influence of the strength growth rate on the pressure on the template side. Its specific value is usually determined by engineering experience or experimental data, rather than direct theoretical calculation. The range of 0.01≤k≤0.03 is based on experience and can provide a reasonable pressure correction effect in most cases. This range not only ensures the rationality of the formula, but also avoids calculation errors caused by excessive or insufficient correction. If this range is found to be inappropriate in some special projects, the specific value of k can be recalibrated and adjusted through experimental data.

[0090] Step 3: Collect the pressure parameters of the connection points of the formwork support unit, number each connection point, analyze the pressure parameters of each connection point, and generate the dynamic load effect index of the support system. The support unit includes support columns, beams and diagonal braces, and the pressure parameters include stress and strain data.

[0091] In the formwork support system for secondary lining concrete pouring, support columns refer to vertical members used to support the formwork. Their main function is to transfer the vertical load of concrete to the foundation or other structures. Support columns are arranged vertically below the formwork system, usually directly supported under the formwork, and evenly distributed to support the entire formwork structure. Crossbeams refer to structural members placed horizontally in the formwork support system, used to connect support columns or directly support the formwork. Diagonal braces are oblique structural members in the formwork support system, used to increase the stability of the entire support system and resist lateral forces, and are installed at a certain angle to form a stable triangular structure.

[0092] During the pouring of the secondary lining concrete, the support columns provide the main vertical support, bearing the weight of the formwork and concrete; the beams distribute the load laterally and help stabilize the formwork structure; the diagonal braces provide additional lateral support to prevent the system from becoming unstable when subjected to lateral forces. These components work together to ensure that the formwork system is stable and safe during the pouring of the secondary lining concrete, ultimately achieving precise forming of the structure.

[0093] The connections of the formwork support unit include the connection between the support column and the beam, the connection between the support column and the diagonal brace, and the connection between the beam and the diagonal brace. The method for generating the dynamic load effect index of the support system is:

[0094]

[0095] Among them, E d represents the dynamic load effect index, S p and ∈ p They represent the stress and strain data of the connection numbered p, respectively, and P represents the total number of connections.

[0096] The connection between the support column and the crossbeam specifically refers to the place where the vertical support column and the horizontal crossbeam intersect and are fixed by some connection method. The connection between the support column and the diagonal brace specifically refers to the place where the vertical support column and the diagonal brace arranged diagonally are connected and fixed. The connection between the crossbeam and the diagonal brace specifically refers to the place where the horizontal crossbeam and the diagonal brace arranged diagonally are connected and fixed.

[0097] The connection between the support column and the beam mainly bears and transfers vertical loads to ensure stable support of the beam. The connection between the support column and the diagonal brace mainly prevents lateral instability of the support column and improves the system's anti-overturning ability. The connection between the beam and the diagonal brace mainly strengthens the stability of the beam under stress and disperses the lateral load. The stress and strain data are directly measured using strain gauges.

[0098] The dynamic load effect index is used to reflect the overall performance of the entire support system under dynamic load. The larger the value of this indicator, the greater the dynamic impact on the system and the higher the potential risk. The product of stress and strain at all connections is accumulated. The product of stress and strain reflects the response strength of the connection under dynamic load. Combining the magnitude of force and the degree of material deformation, the product of stress and strain at all connections is added up to obtain the dynamic load effect index of the entire support system.

[0099] If E d A high value indicates that the support system is subject to large forces and deformations under dynamic loads, which means that the system is close to its design limit or there is a high structural risk. dA lower value indicates that the system is subjected to less stress and deformation and is in a relatively safe working state. By comprehensively considering the stress and strain at each connection, a comprehensive index is calculated that can reflect the performance of the entire formwork support system under dynamic load.

[0100] Step 4: Obtain the intrinsic parameters of each supporting column, each beam and each diagonal brace, and collect the plate parameters of the formwork, which include the plate thickness and area of ​​the formwork, the bending strength data of the formwork material and the support span. Combine the acquired intrinsic parameters and plate parameters to build an analysis model to generate the comprehensive bearing capacity data of the formwork support system.

[0101] The supporting column's own parameters include the cross-sectional area of ​​the supporting column and the compressive strength data of the supporting column material; the beam's own parameters include the yield strength of the beam material, the beam's width, height, support span and safety factor; the brace's own parameters include the cross-sectional area of ​​the brace and the compressive strength of the brace material.

[0102] The specific method for generating the comprehensive bearing capacity data of the formwork support system is:

[0103] The cross-sectional area of ​​each support column and the compressive strength data of the support column material are multiplied to obtain the bearing capacity data of each support column, and the bearing capacity data of all support columns are summed to obtain the total bearing capacity data of the support columns;

[0104] The cross-sectional area of ​​each brace is multiplied by the compressive strength of the brace material to obtain the bearing capacity data of each brace, and the bearing capacity data of all braces are summed to obtain the total bearing capacity data of the braces;

[0105] The load-bearing capacity of each beam is calculated based on the yield strength of the beam material, the width, height, support span and safety factor of the beam. The formula used is:

[0106]

[0107] Among them, Hl ρ represents the load-bearing capacity of the ρth beam, HFy ρ represents the yield strength of the material of the ρth beam, b ρ ,Hh ρ , L ρ and γ ρ They represent the width, height, support span and safety factor of the ρth beam material respectively. ρ represents the beam number, ρ = 1, 2, ..., Hl N , Hl N is the total number of beams, and the safety factor of the beam is the ratio between the ultimate load-bearing capacity of the beam and the design load.

[0108] The total bearing capacity data of the beams is generated by superimposing the bearing capacity data of all beams, and the bearing capacity data of the template is generated according to the plate parameters of the template. The formula is:

[0109]

[0110] Among them, Mb z Indicates the bearing capacity data of the template, Mh and A represent the thickness and area of ​​the plate respectively, Mf p It represents the bending strength of the formwork material, and Mk represents the support span of the formwork.

[0111] The total bearing capacity data of the supporting columns and diagonal braces can indicate whether the formwork support system can maintain a safe state when bearing the expected load. The cross-sectional area of ​​the supporting columns and diagonal braces is directly obtained from the structural design drawings. The dimensions of each supporting member will be marked on the design drawings, so as to calculate the cross-sectional area. The compressive strength data of commonly used building materials have been standardized in the relevant material manuals or building specifications and can be directly consulted. For specific building materials, the design value of compressive strength and material performance data can be obtained from the material supplier or manufacturer. The bearing capacity refers to the maximum load that a structure or component can withstand without being damaged. The supporting columns and diagonal braces play a bearing role in the structure. The calculation of bearing capacity is based on the basic mechanical properties of the material. When the load is applied, the bearing capacity of the component can be expressed by the product of its cross-sectional area and the compressive strength of the material. In the structure, the supporting columns and diagonal braces usually work in parallel. The calculation logic of the total bearing capacity accumulates the bearing capacity of each supporting member through simple addition, reflecting the bearing capacity of the entire system. This is because in a parallel structure, the increase in the load of any supporting member will not affect the load bearing of other members.

[0112] The yield strength of a material is the stress of the material when it reaches the yield point. This stress level determines the maximum load that the beam can withstand before permanent deformation or failure. The width of the beam affects its load-bearing capacity. The larger the width, the higher the load-bearing capacity of the beam. The square of the height represents the bending resistance of the beam. The bending resistance of the beam is proportional to the square of the height, because the moment of inertia of the beam plays a key role in the bending resistance of the beam. The support span is the distance between the support points at both ends of the beam. The larger the span, the greater the bending moment of the beam, so the load-bearing capacity is reduced accordingly. The safety factor is the ratio between the ultimate load-bearing capacity and the design load. By introducing the safety factor, it is ensured that the design of the beam is still safe when considering uncertainties and potential dangers.

[0113] The bearing capacity of a beam is the maximum load that the beam can withstand under design conditions. The yield strength is proportional to the bearing capacity. The higher the yield strength, the greater the stress that the material can withstand, and thus the greater the bearing capacity of the beam. The width of the beam is proportional to the bearing capacity. As the width increases, the cross-sectional area of ​​the beam increases, thereby increasing the bearing capacity of the beam. The square of the height of the beam is proportional to the bearing capacity. The square of the height reflects the change in the bending resistance of the beam. The higher the height of the beam, the greater its bending resistance, thereby increasing the bearing capacity. The support span is inversely proportional to the bearing capacity. The larger the span, the greater the bending moment that the beam needs to withstand, so the bearing capacity will decrease when the span increases. The safety factor is inversely proportional to the bearing capacity. The larger the safety factor, the more conservative the design requirements, resulting in a lower calculated bearing capacity.

[0114] Furthermore, based on the total bearing capacity data of the supporting columns, diagonal braces, beams and the bearing capacity data of the formwork, the comprehensive bearing capacity data of the formwork support system is generated according to the following method:

[0115]

[0116] Among them, Zh C Represents the comprehensive bearing capacity data of the formwork support system, Zc z 、Xc z and Hl z They respectively represent the total bearing capacity data of the supporting column, the diagonal brace and the cross beam, θ1, θ2 and θ3 respectively represent the first weight coefficient, the second weight coefficient and the third weight coefficient, and 2>θ1>1>θ2>θ3≥0.5.

[0117] The comprehensive bearing capacity data reflects the comprehensive bearing capacity of the supporting columns, diagonal braces, beams and the formwork itself. This embodiment combines the bearing capacity of each component to obtain the overall bearing capacity of the entire system. The calculation method of the comprehensive bearing capacity data adopts the form of square root of the sum of squares, which is similar to the calculation method of Euclidean distance. It is used to integrate various influencing factors to avoid a single factor from excessively dominating the overall result.

[0118] Logarithmic function log(Xc z +1) is used to smooth the total load-bearing capacity of the diagonal brace to prevent it from contributing too much to the total load-bearing capacity, while ensuring that no matter Xc z Whatever the value, there will be a positive contribution. Adding 1 is to prevent z Mathematical error in logarithmic operation when it is 0, exponential function Used to enhance the contribution of template bearing capacity to the system's comprehensive bearing capacity, the exponential function will significantly amplify Mb z To Zh c The influence of the formwork, especially when the bearing capacity of the formwork is large, highlights its importance in the overall structure.

[0119] By setting different weight coefficients θ1, θ2 and θ3, the influence of supporting columns, diagonal braces, beams and formwork on the comprehensive bearing capacity in different situations can be reflected. The weight coefficient θ1 of supporting columns is larger, reflecting that supporting columns play a more important supporting role in the system, while the weight coefficients of beams and formwork are smaller, reflecting that their roles are relatively weak or secondary.

[0120] θ1 is between 1 and 2, reflecting that the support column occupies a major position in the formwork support system. The support column is usually the main load-bearing force, so assigning a higher weight coefficient helps to accurately reflect its importance.

[0121] θ1>1>θ2>θ3 reflects that the effect of the diagonal brace is inferior to that of the supporting column but stronger than the formwork. The role of the diagonal brace is to provide additional stability for the support system, so its weight should be between the supporting column and the formwork. θ3 is between 0.5 and 1, indicating that the bearing capacity of the formwork has a certain influence on the overall system, but its effect is relatively small compared with the supporting column and the diagonal brace. The formwork mainly bears direct loads, but its contribution to the overall stability of the system is relatively weak, so its weight is the lowest.

[0122] The comprehensive bearing capacity data reflects the total bearing capacity of the entire formwork support system under the combined effect of the bearing capacities of all components, and represents the overall stability and safety of the system under the action of external forces. This data not only takes into account the bearing capacity of each individual component, but also reflects the interaction between them and the impact on the overall structure.

[0123] When the bearing capacity of the supporting column increases, the bearing capacity of the whole system will also be significantly improved. The total bearing capacity of the diagonal brace is processed by logarithmic function, and its contribution is relatively smooth and stable. The additional support provided by the diagonal brace can enhance the overall stability of the system, but its role is controlled within a reasonable range and does not dominate the bearing capacity of the system. The contribution of the beam bearing capacity to the comprehensive bearing capacity is reflected by a smaller weight coefficient θ2. The beam is a connecting part in the whole system, so its bearing capacity has an impact on the system but is not as important as the supporting column. The bearing capacity data of the template is fitted by an exponential function, and its contribution to the comprehensive bearing capacity is rapidly amplified when the value is high. When the template bearing capacity is high, its role becomes more significant.

[0124] Through the reasonable weight distribution and the application of smoothing functions (logarithmic, exponential), it is ensured that the contribution of each part of the supporting column, diagonal brace, beam and formwork is reasonably considered, so that the overall imbalance will not be caused by a certain part being too strong, nor will it be ignored because of a certain part being too weak. z 、Xc z and Hl zThe relationship and weights reflect the needs and structural characteristics in actual engineering. Support columns as main load-bearing components require higher weights, while diagonal braces and formwork, as secondary supports and load-bearing structures, have relatively lower weights.

[0125] Step 5: Add the corrected lateral pressure data of the formwork and the dynamic load effect index to obtain the total lateral pressure. Generate a safety factor based on the total lateral pressure and the comprehensive bearing capacity data. Compare the safety factor with the safety threshold to determine the safety of the formwork support system.

[0126] The safety factor generated based on the total lateral pressure and comprehensive bearing capacity data is as follows:

[0127]

[0128] Among them, Zc y Indicates the total side pressure, P x Indicates the side pressure data of the modified template, E d The dynamic load effect index SF represents the safety factor. If SF<SF y If the support is insufficient, an early warning will be issued; otherwise, no early warning will be issued. y Indicates the safety threshold.

[0129] The corrected lateral pressure data of the formwork is the lateral pressure that the formwork may bear during the construction process, including the lateral force caused by concrete pouring, etc. The dynamic load effect index reflects the additional load effect caused by vibration, impact or other dynamic factors during the construction process. The superposition of the two reflects the total lateral pressure that the formwork support system may bear under actual construction conditions. Ensure that all potential external loads are taken into account during the assessment process.

[0130] The safety factor is determined by comparing the system's comprehensive load-bearing capacity with the total lateral pressure that it may actually withstand. The higher the safety factor, the greater the system's load-bearing capacity is than the actual applied pressure, and thus the higher the safety.

[0131] The greater the total lateral pressure, the smaller the safety factor. An increase in total lateral pressure means that the system faces a greater external load. Therefore, if the carrying capacity does not increase accordingly, safety will decrease. The greater the comprehensive carrying capacity, the higher the safety factor. This is because an increase in carrying capacity means that the system can withstand greater external pressure, thereby improving safety.

[0132] If SF ≥ SF y , which means that the system's safety factor is above the safety threshold, indicating that the formwork support system has sufficient bearing capacity and no warning is needed. y, it indicates that the safety factor is lower than the safety threshold, which means that the system's carrying capacity may not be sufficient to cope with the actual pressure, there is a potential risk, and an early warning of insufficient support needs to be issued.

[0133] The core of the early warning mechanism is to determine the safety of the formwork support system by calculating the safety factor and comparing it with the preset safety threshold. If the safety factor is less than the safety threshold, the system will issue an early warning of insufficient support, prompting the engineer to take necessary actions. The design logic of this mechanism is to ensure safety during construction, dynamically respond to changes in construction, reduce accident risks, and ensure that the project complies with relevant specifications and standards.

[0134] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0135] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete, characterized in that: The specific steps include: Step 1: Real-time collection of internal environmental data of poured concrete, concrete gravity density and pouring height data, wherein the internal environmental data includes internal temperature and internal humidity data, and the strength growth rate of concrete is calculated through the internal environmental data, and the lateral pressure of the formwork is obtained through the concrete gravity density and pouring height data; Step 2: Collect external environmental data of the pouring site, the external environmental data including ambient temperature and ambient humidity data of the pouring site, analyze the external environmental data to obtain an environmental impact correction coefficient, use the strength growth rate and the environmental impact correction coefficient to correct the lateral pressure of the formwork, and obtain the corrected lateral pressure data of the formwork; Step 3: Collect the pressure parameters of the connection points of the formwork support unit, number each connection point, analyze the pressure parameters of each connection point, and generate the dynamic load effect index of the support system. The support unit includes support columns, beams and diagonal braces, and the pressure parameters include stress and strain data. Step 4: Obtain the parameters of each supporting column, each beam and each diagonal brace, and collect the plate parameters of the template, which include the thickness and area of ​​the template, the bending strength data of the template material and the support span. Combine the acquired parameters and the plate parameters to build an analysis model to generate the comprehensive bearing capacity data of the template support system; Step 5: Add the corrected lateral pressure data of the formwork and the dynamic load effect index to obtain the total lateral pressure. Generate a safety factor based on the total lateral pressure and the comprehensive bearing capacity data. Compare the safety factor with the safety threshold to determine the safety of the formwork support system.

2. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 1, characterized in that: The strength growth rate of concrete calculated by internal environmental data is as follows: According to the thickness of the poured concrete, multiple sets of internal temperature data and internal humidity data of different thickness areas are collected at equal thickness intervals, and analyzed to obtain the strength growth rate. The formula is: Among them, R q represents the intensity growth rate, T0 and H0 are standard temperature data and standard humidity data respectively, R0 is the intensity growth rate under standard temperature and standard humidity, α and β are temperature empirical coefficient and humidity empirical coefficient respectively, α>β>0 and α+β=1, N represents the total number of groups of internal temperature data and internal humidity data collected, T i and H i Respectively represent the i-th group of internal temperature data and internal humidity data.

3. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 2, characterized in that: The environmental impact correction coefficient obtained by analyzing the external environmental data is as follows: According to the height of concrete pouring, collect multiple sets of ambient temperature and humidity data on the template surface at equal height intervals on the side of the template, and calculate the environmental impact correction coefficient based on the formula: Among them, R e represents the environmental impact correction coefficient, M represents the total number of sets of collected ambient temperature and ambient humidity data, Te j 、He j They respectively represent the ambient temperature and ambient humidity data of the jth group of template surfaces.

4. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 1, characterized in that: The lateral pressure of the formwork is obtained by the gravity density of concrete and the pouring height data as follows: Determine the gravity density of concrete based on the concrete mix ratio, measure the height of concrete pouring, combine the gravity density of concrete and the height of concrete pouring, and calculate the lateral pressure of the formwork based on the formula: P0=γ c *h Among them, P0 represents the lateral pressure of the template, γ c represents the gravity density of concrete, and h represents the height of concrete pouring.

5. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 4, characterized in that: The specific formula for correcting the side pressure of the template is: P x =P0*(1-k*R q ) / R e Among them, P x Represents the side pressure data of the modified template, R e Represents the environmental impact correction factor, R q represents the strength growth rate, k represents the adjustment coefficient, and the value range of the adjustment coefficient is: 0.01≤k≤0.

03.

6. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 1, characterized in that: The connections of the formwork support unit include the connection between the support column and the beam, the connection between the support column and the diagonal brace, and the connection between the beam and the diagonal brace. The method for generating the dynamic load effect index of the support system is: Among them, E d represents the dynamic load effect index, S p and ∈ p They represent the stress and strain data of the connection numbered p, respectively, and P represents the total number of connections.

7. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 1, characterized in that: The supporting column's own parameters include the cross-sectional area of ​​the supporting column and the compressive strength data of the supporting column material; the beam's own parameters include the yield strength of the beam material, the beam's width, height, support span and safety factor; the brace's own parameters include the cross-sectional area of ​​the brace and the compressive strength of the brace material.

8. The method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 7, characterized in that: The specific method for generating the comprehensive bearing capacity data of the formwork support system is: The cross-sectional area of ​​each support column and the compressive strength data of the support column material are multiplied to obtain the bearing capacity data of each support column, and the bearing capacity data of all support columns are summed to obtain the total bearing capacity data of the support columns; The cross-sectional area of ​​each brace is multiplied by the compressive strength of the brace material to obtain the bearing capacity data of each brace, and the bearing capacity data of all braces are summed to obtain the total bearing capacity data of the braces; The load-bearing capacity of each beam is calculated based on the yield strength of the beam material, the width, height, support span and safety factor of the beam. The formula is: Among them, Hl ρ represents the load-bearing capacity of the ρth beam, HFy ρ represents the yield strength of the material of the ρth beam, b ρ ,Hh ρ , L ρ and γ ρ They represent the width, height, support span and safety factor of the ρth beam material respectively. ρ represents the beam number, ρ = 1, 2, ..., Hl N , Hl N is the total number of beams, and the safety factor of the beam is the ratio between the ultimate load-bearing capacity of the beam and the design load; The total bearing capacity data of the beams is generated by superimposing the bearing capacity data of all beams, and the bearing capacity data of the template is generated according to the plate parameters of the template. The formula is: Among them, Mb z Indicates the bearing capacity data of the template, Mh and A represent the thickness and area of ​​the plate respectively, Mf p It represents the bending strength of the formwork material, and Mk represents the support span of the formwork; Based on the total bearing capacity data of supporting columns, diagonal braces, beams and the bearing capacity data of the formwork, the comprehensive bearing capacity data of the formwork support system is generated according to the following method: Among them, Zh C Represents the comprehensive bearing capacity data of the formwork support system, Zc z 、Xc z and Hl z They respectively represent the total bearing capacity data of the supporting column, the diagonal brace and the cross beam, θ1, θ2 and θ3 respectively represent the first weight coefficient, the second weight coefficient and the third weight coefficient, and 2>θ1>1>θ2>θ3≥0.

5.

9. A method for monitoring the pressure on the formwork side during the pouring of secondary lining concrete according to claim 8, characterized in that: The safety factor generated based on the total lateral pressure and comprehensive bearing capacity data is as follows: Among them, Zc y Indicates the total side pressure, P x Indicates the side pressure data of the modified template, E d The dynamic load effect index SF represents the safety factor. If SF<SF y If the support is insufficient, an early warning will be issued; otherwise, no early warning will be issued. y Indicates the safety threshold.

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