Evaluation Methods and Devices for Active Protection and Backup Scheme of T-beam Wet Joints

Abstract

This invention relates to the field of computer design technology, and particularly to a method and device for evaluating an active protection backup scheme for wet joints of T-beams. The method includes the following steps: S1: Obtaining a set of construction environment parameters; S2: Setting the scheme to be evaluated; S3: Verifying the stiffness and strength of the scheme under simulated static and wind loads, and verifying the sway amplitude under wind load; if all verifications pass, proceed to S4; otherwise, proceed to S5; S4: Calculating the manufacturing cost of the scheme to be evaluated, then calculating and recording the cost-effectiveness index; S5: Analyzing the impact of changes in each design variable in the scheme to be evaluated on each verification item, and calculating the priority of each design variable's impact based on the safety margin, adjusting the design variable with the highest priority to form a new scheme to be evaluated; S6: After iterations of S3 to S5, outputting the scheme to be evaluated with the highest cost-effectiveness index as the final scheme. This invention can calculate the optimal cost-effectiveness scheme according to different construction environments.

Description

Technical Field

[0001] This invention relates to the field of computer design technology, and in particular to an evaluation method and device for an active protection backup scheme for wet joints of T-beams. Background Technology

[0002] In bridge construction, the gaps formed at the wet joints of adjacent T-beams due to lack of concrete pouring are a major source of falling objects, seriously threatening the safety of passage under the bridge. Traditionally, safety passages are constructed under the bridge for protection. However, these passages require significant construction and dismantling costs, extend the construction period, are difficult to adapt to complex construction sites, and are a passive protection measure—protecting a specific area after a falling object has occurred—therefore, significant safety hazards remain.

[0003] An active protection backup device is proposed, such as... Figure 1 As shown, this device, composed of a steel crossbeam 1, a steel wire rope 2, and a steel plate trough 3, forms a fully enclosed bottom protection layer below the wet joint, thereby directly preventing objects from falling from heights. However, different sizes of the active protection bottom protection device significantly impact its cost and protective effect. Therefore, a method is needed to calculate the optimal active protection bottom protection scheme based on different construction environments to achieve the best cost-effectiveness. Summary of the Invention

[0004] This invention provides an evaluation method and device for an active protection and backup scheme for wet joints of T-beams, which can effectively solve the problems in the background art.

[0005] This invention provides an evaluation method for an active protection backup scheme for wet joints of T-beams, comprising the following steps:

[0006] S1: Obtain the construction environment parameter set;

[0007] S2: Set up an evaluation scheme with multiple design variables having initial values;

[0008] S3: Based on the construction environment parameter set, simulate static load and wind load to verify the stiffness and strength of the scheme to be evaluated, and calculate the sway amplitude of the scheme to be evaluated under wind load to verify whether it will produce gaps that could lead to falling objects and leakage; if all the above verifications are passed, proceed to S4; otherwise, proceed to S5.

[0009] S4: Calculate the production cost of the solution to be evaluated, then calculate and record the cost-effectiveness index of the solution to be evaluated;

[0010] S5: Analyze the impact of changes in each design variable in the scheme to be evaluated on stiffness, strength, sway amplitude and manufacturing cost, and calculate the impact priority of each design variable in combination with the safety margin of each verification project. Adjust the design variable with the highest impact priority to form a new scheme to be evaluated.

[0011] S6: Repeat S3~S5 until the set number of repetitions or multiple consecutive times the cost-effectiveness index improves very little, then output the solution with the highest cost-effectiveness index as the final solution.

[0012] Furthermore, in step S1, the construction environment parameter group includes the maximum falling object weight Mdro and the maximum fall height Hdro;

[0013] In step S3, the specific steps for verifying the stiffness and strength of the scheme to be evaluated are as follows:

[0014] The impact force generated by the maximum weight of the falling object at the maximum drop height is converted into the ultimate equivalent static load by using a dynamic amplification model.

[0015] Calculate whether the stiffness and strength of each component in the scheme to be evaluated are within the set safety threshold under the ultimate equivalent static load. If they are, the verification is successful.

[0016] Furthermore, the specific calculation process for the ultimate equivalent static load is as follows:

[0017] Let N be the maximum number of falling objects that the proposed scheme can withstand.

[0018] Ultimate equivalent static load Fload = kdro·Hdro·Mdro + N·Mdro + Moth + Mself;

[0019] Where kdro is the set amplification factor;

[0020] Moth is a flexible load setting;

[0021] Mself is the weight of the scheme to be evaluated.

[0022] Furthermore, in step S1, the construction environment parameter group includes the maximum vertical wind speed Vwind;

[0023] In step S3, the specific steps for calculating the swing amplitude are as follows:

[0024] The area of ​​the vertical plane is S = L·H;

[0025] Where L is the length of the steel plate groove in the scheme to be evaluated, and H is the depth of the steel plate groove in the scheme to be evaluated;

[0026] Wind load Fwind = 0.5·P / (R·T)·Vwind²·Cd·S;

[0027] Where P is the local average atmospheric pressure;

[0028] R is the set gas constant;

[0029] T represents the local average temperature;

[0030] Cd is the set drag coefficient;

[0031] Calculate the static pendulum angle θ = arcsin(Fwind / (Mself·g));

[0032] Mself is the self-weight of the scheme to be evaluated;

[0033] g is the gravitational acceleration constant;

[0034] Calculate the gap size Lchi = sinθ·Lrope;

[0035] Where Lrope is the length of the wire rope;

[0036] If the gap size Lchi is less than the set threshold, the verification is successful.

[0037] Furthermore, in step S4, the specific steps for calculating the cost-effectiveness index are as follows:

[0038] Calculate the margin coefficient for each validation item, and denote the margin coefficient of the i-th validation item as Smari, Smari=[σ]i / σacti-1;

[0039] Where [σ]i is the threshold of the i-th verification item;

[0040] σacti is the actual value of the i-th verification item;

[0041] Cost-effectiveness index (CPR) = (ΣSmari) / Cost;

[0042] Cost is the production cost of the proposed solution.

[0043] ΣSmari is the sum of the margin coefficients for all validation items.

[0044] Furthermore, in step S5, the specific steps for analyzing the influence of each design variable are as follows:

[0045] Set the minimum change value of the m-th design variable to Δxm;

[0046] After calculating the minimum change value △xm of the m-th design variable, the change of the n-th verification item is △σmn, and the sensitivity of the n-th verification item is △Fmn=(△σmn / [σ]n) / (△xm / Rxm);

[0047] Where [σ]n is the threshold of the nth verification item;

[0048] Rxm is the range of the specified range of the m-th design variable;

[0049] Calculate the percentage change in manufacturing cost after the m-th design variable increases by the minimum change value Δxm, denoted as ΔCm. The sensitivity of manufacturing cost is ΔCFm = ΔCm / (Δxm / Rxm).

[0050] For each design variable, calculate its impact priority;

[0051] The influence priority of the m-th design variable is Sm = Σ0.3·Smarn·△Fmn-0.1·△CFm;

[0052] After calculating the priority of the impact of all design variables, the value of the design variable with the highest priority is adjusted.

[0053] Furthermore, each time a design variable is adjusted, the design variable is counted. When the count of a design variable reaches a set limit value, the design variable is restored to its initial value, and then the adjustment direction is changed.

[0054] Furthermore, step S2 also includes determining the value range of each design variable based on the obtained construction environment parameter set.

[0055] Furthermore, in step S2, when setting the initial values ​​of multiple design variables, for any design variable, first determine the range of values ​​for that design variable, and then use the midpoint value between the midpoint of the range and the extreme point on the safer side of the design variable as the initial value of that design variable.

[0056] The present invention also provides an evaluation device for an active protection backup scheme for wet joints of T-beams, comprising a storage unit and a processor. The storage unit is used to store one or more program instructions; the processor is used to run one or more program instructions to perform the steps of the above-mentioned evaluation method for active protection backup schemes of wet joints of T-beams.

[0057] The technical solution of this invention can achieve the following technical effects:

[0058] The proposed evaluation method, through simulating the ultimate equivalent static load and wind load, combined with cost-effectiveness quantification methods that balance safety and economy, can intelligently and quickly calculate and iterate the optimal design scheme according to different construction environments. Furthermore, during the iterative calculation process, it can automatically identify the design variables that most need adjustment in the scheme to be evaluated and make targeted adjustments to the scheme to be evaluated, thereby enabling faster iteration to the optimal scheme and saving computing power. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a schematic diagram of the active protection backstop device in the background technology;

[0061] Figure 2 This is a flowchart of an evaluation method for an active protection backup scheme for wet joints of T-beams in this invention;

[0062] Attached reference numerals: 1. Reinforcing bar crossbeam; 2. Wire rope; 3. Steel plate channel. Detailed Implementation

[0063] The basic principles and main features of the technical solution of the present invention will be described below with reference to the accompanying drawings of the embodiments of the present invention. The following description will use one or more embodiments for a more intuitive understanding. These embodiments are merely some, not all, of the embodiments of the present invention.

[0064] In the description of this invention, the terms indicating orientation or positional relationship (such as up, down, left, right, etc.) are based on the orientation shown in the drawings or some conventional positional relationships, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the features referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0065] This invention provides an evaluation method for an active protection backup scheme for wet joints of T-beams. The main idea of ​​this method is to first pre-define an active protection backup scheme to be evaluated. By verifying various parameters of this scheme, the most critical design variable requiring adjustment can be identified and adjusted. Through this method, the scheme is iteratively optimized in a targeted manner, thereby quickly obtaining an optimal design scheme. The specific steps of this method are as follows:

[0066] S1: Obtain multiple construction environment parameters required for verification and iterative calculations, and form a construction environment parameter group. The construction environment parameters should include at least the following parameters:

[0067] The maximum falling object weight (Mdro) is determined based on construction techniques and historical data statistics. It is the weight of the largest object that is assumed to fall during construction.

[0068] The maximum fall height (Hdro) is determined based on construction techniques and historical data statistics. It is the maximum height at which an object is assumed to fall onto the active protection bottom support device during construction.

[0069] Maximum vertical wind speed Vwind is determined by identifying the maximum wind speed perpendicular to the joint direction based on historical or forecasted weather conditions at the construction site.

[0070] The average atmospheric pressure P and average temperature at the construction site during the construction period are determined based on historical or forecasted weather conditions at the construction site, or by on-site measurements.

[0071] For the joint width, the joint width between the two T-beams is measured on site, and the maximum value is taken as the final joint width.

[0072] Market prices of each component in the active protection backup solution;

[0073] The above construction environment parameters are parameters that need to be re-determined when designing an active protection backup plan for each joint.

[0074] S2: Set multiple design variables with initial values ​​for the scheme to be evaluated. The design variables are the parameters of each component in the protection bottom-line scheme, including at least the diameter of the steel bar crossbeam 1, the length L of the steel plate groove 3, the depth H of the steel plate groove 3, the thickness of the steel plate groove 3, the length Lrope of the steel wire rope 2, the diameter of the steel wire rope 2, and the number of steel wire ropes 2.

[0075] S3: This step verifies the structural reliability of the scheme to be evaluated. In most cases, the falling object is within the tolerance range of the active protection bottom-up device. However, as a protective device, it must be considered under the most extreme conditions. This step mainly verifies the reliability of the active protection bottom-up device under extreme working conditions.

[0076] First, simulated static and wind loads are generated based on the set of construction environment parameters;

[0077] The simulated static load is to convert the impact of the falling object on the active protection bottom support device into an equivalent static object placed on the active protection bottom support device. In this way, the stiffness (i.e. bending resistance) and strength (i.e. fracture resistance) of the steel bar crossbeam 1, steel wire rope 2 and steel plate channel 3 can be quickly verified using the static load calculation formula.

[0078] Because the joints of bridges are very long (usually tens of meters), the steel plate channel 3 cannot be made that long. Therefore, multiple active protection bottom-support devices will be used for one joint. The simulated wind load is the force applied to the active protection bottom-support device when the wind blows it. This force may cause the active protection bottom-support device to tilt and sway, thereby creating gaps between two adjacent active protection bottom-support devices. Objects such as bolts and small cement blocks may fall out through the gaps. Therefore, it is necessary to verify whether the active protection bottom-support device will create gaps that lead to leakage of falling objects when the wind force is at its maximum and the active protection bottom-support device has the maximum swing amplitude.

[0079] If all the above verifications pass, proceed to S4 for cost and cost-effectiveness calculations; otherwise, if the verifications fail, proceed to S5 to directly modify the design variables in the scheme to be evaluated.

[0080] S4: This step calculates the manufacturing cost of the scheme to be evaluated based on the parameters of each design variable within the scheme to be evaluated. It should be noted that the manufacturing cost is the total cost of multiple active protection bottom-covering devices required to cover the entire T-beam joint, not the cost of a single active protection bottom-covering device. Then, the cost-effectiveness index of the scheme to be evaluated is calculated. The physical meaning of the cost-effectiveness index is the ratio of the comprehensive safety margin to the manufacturing cost. For any verification project, the larger its corresponding safety margin, that is, under the extreme state of simulated static load or wind load, the greater the safety margin of the verification project, and the further away its value is from the danger line. If the manufacturing cost is relatively small at this time, the value of the cost-effectiveness index will become larger, which means that the cost-effectiveness of the scheme to be evaluated is higher.

[0081] After calculating the cost-effectiveness index of the scheme to be evaluated, it is necessary to record the various design variables and the cost-effectiveness index of the scheme in the corresponding data table.

[0082] S5: To avoid exhaustive enumeration and wasting computing power, this step is used to identify the design variable that needs the most modification in the scheme to be evaluated. Since changes in each design variable may affect all verification items, for example, if the depth of the steel plate trough 3 increases, the wind thrust received will be greater, but the stiffness of the steel plate trough 3 will increase. Therefore, this step will analyze the impact of changes in each design variable in the scheme to be evaluated on stiffness, strength, sway amplitude and manufacturing cost, and combine the safety margin of each verification item to comprehensively calculate the impact priority of each design variable. Then, the design variable with the highest impact priority will be adjusted to form a new scheme to be evaluated.

[0083] S6: Repeat S3~S5 until the set number of repetitions, or when the cost-effectiveness index improves very little for several consecutive times, it means that the solution to be evaluated has basically reached the optimal state. At this point, the iteration can be stopped, and the solution to be evaluated with the highest cost-effectiveness index is output as the final solution.

[0084] The simulated static load can be calculated using the following method:

[0085] First, in step S1, it is necessary to ensure that the maximum falling object weight Mdro and the maximum fall height Hdro are recorded in the construction environment parameter group, and verify the most recent update time of these two parameters to prevent the omission of these two data or the personnel forgetting to update them from affecting the final calculation accuracy.

[0086] In step S3, the specific steps for verifying the stiffness and strength of the scheme to be evaluated are as follows:

[0087] The impact force generated by the maximum weight of the falling object at the maximum drop height is converted into the ultimate equivalent static load by using a dynamic amplification model.

[0088] The calculation verifies whether the stiffness and strength of each component in the evaluated scheme are within the set safety threshold under the ultimate equivalent static load. The shapes of each component of this active protection bottom-line device are all standard shapes. Under the condition of determining its static load, the actual stress of each component can be calculated by using deflection calculation formula, material yield strength calculation formula, normal stress calculation formula, shear force calculation formula, tensile strength calculation formula, etc. The specific algorithm is existing technology and will not be elaborated here. Then, the calculated actual situation is compared with the corresponding threshold. If all actual stress situations are less than their corresponding thresholds, the verification is passed.

[0089] The specific calculation process for the ultimate equivalent static load is as follows:

[0090] Let N be the maximum number of falling objects that the scheme to be evaluated can withstand. That is, if the largest falling object is used to fill the entire steel plate groove 3, a maximum of N objects can be laid. If the number of falling objects exceeds N, the falling objects will protrude from the joint between the T beams, and personnel can clearly find and deal with the falling objects. It should be noted that this is a very extreme hypothetical situation. Under normal circumstances, the number of falling objects will not be that many.

[0091] Ultimate equivalent static load Fload = kdro·Hdro·Mdro + N·Mdro + Moth + Mself;

[0092] Where kdro is a magnification factor set by the user;

[0093] Moth provides flexible loads that are manually configured.

[0094] Mself is the weight of the active protection backstop device manufactured for the proposed solution.

[0095] The physical meaning of the above formula is as follows:

[0096] kdro·Hdro·Mdro calculates the impact force generated when the largest falling object falls from the highest point onto the active protection bottom cover device, converting it into an equivalent static load.

[0097] Now consider an extreme case: the steel plate trough 3 is already full of falling objects, but the falling objects just cover the entire steel plate trough 3 and the personnel do not notice it. At this time, new falling objects fall on this active protection bottom cover device. Therefore, the weight of the existing N falling objects N·Mdro must be added to the ultimate equivalent static load Fload.

[0098] In the same extreme case described above, the flexible load Moth falls onto the active protection bottom-stop device without being noticed by personnel. The flexible load refers to the load that can be quickly detected and removed once it falls onto the active protection bottom-stop device, such as when personnel or equipment accidentally step on the active protection bottom-stop device. Therefore, the flexible load Moth should be added to the extreme equivalent static load Fload.

[0099] The ultimate equivalent static load Fload obtained by adding the above three loads will be a very extreme case. If the stiffness and strength of each component of the active protection bottom-line device made by the scheme to be evaluated are still within the threshold under this case, then its safety can be well guaranteed during normal use.

[0100] The simulated wind load can be calculated using the following method:

[0101] In step S1, it is necessary to ensure that the maximum vertical wind speed Vwind is recorded in the construction environment parameter group, and to verify the most recent update time of this parameter to prevent data omission or personnel forgetting to update it, which would affect the final calculation accuracy.

[0102] In step S3, the specific steps for calculating the swing amplitude are as follows:

[0103] First, calculate the vertical surface area S=L·H, where L is the length of the steel plate trough 3 in the scheme to be evaluated, and H is the depth of the steel plate trough 3 in the scheme to be evaluated; the vertical surface is the side surface of the steel plate trough 3, which is the surface that will be directly blown by the wind, and the thrust of the wind will be entirely applied to this surface.

[0104] Wind load Fwind = 0.5·P / (R·T)·Vwind²·Cd·S;

[0105] Where P is the local average atmospheric pressure;

[0106] R is the set gas constant;

[0107] T represents the local average temperature;

[0108] Cd is the set drag coefficient, a dimensionless coefficient that reflects the influence of the object's shape and windward orientation on wind force, and is used to quantify the object's wind-blocking effect.

[0109] The physical meaning of the above formula is as follows:

[0110] P / (R·T) is used to calculate the weight of air per unit space in a construction site (approximate to the air density). When wind blows onto a vertical surface, it is equivalent to a certain weight of air impacting the vertical surface. The wind load Fwind can be regarded as the impact kinetic energy of this mass of air impacting the vertical surface at the fastest speed. The above formula is a conversion calculation of this.

[0111] After obtaining the simulated wind load, consider an extreme case: when the active protection bottom-holding device is at its lightest (i.e., no falling object has yet entered the steel plate trough 3), a continuous wind load acts on the vertical surface, pushing the active protection bottom-holding device to swing to its maximum angle and reach a state of force equilibrium where it remains stationary. Let the active protection bottom-holding device swing by an angle θ at this point. The force in the wind direction at this time is sinθ·Mself·g = Fwind. After conversion, the formula for calculating the static swing angle θ can be obtained:

[0112] Calculate the static pendulum angle θ = arcsin(Fwind / (Mself·g));

[0113] Where Mself is the self-weight of the scheme to be evaluated; g is the gravitational acceleration constant.

[0114] Once the maximum swing angle of the active protection bottom cover device is known, the maximum gap size that the active protection bottom cover device will generate after swinging can be calculated. The gap size is calculated as Lchi = sinθ·Lrope.

[0115] Where Lrope is the length of wire rope 2;

[0116] If the gap size Lchi is less than the set threshold, the verification is successful.

[0117] Preferably, in step S4, the specific steps for calculating the cost-effectiveness index are as follows:

[0118] The aforementioned stiffness, strength, and sway amplitude verification items, including deflection verification, material yield strength verification, normal stress strength verification, shear strength verification, tensile strength verification, and sway amplitude verification for each component, are ordered as needed, such as 1, 2, etc.

[0119] Calculate the margin coefficient for each validation item, and denote the margin coefficient of the i-th validation item as Smari, Smari=[σ]i / σacti-1;

[0120] Where [σ]i is the threshold of the i-th verification item;

[0121] σacti is the actual value of the i-th verification item;

[0122] The margin coefficient reflects the difference between the calculated corresponding strength and its threshold under simulated static load and wind load in each verification project. The larger the margin coefficient, the further the corresponding strength is from the threshold, which means that this performance is relatively excessive. For example, if the margin coefficient in the deflection verification of steel plate trough 3 is very large, it means that the bending deformation of steel plate trough 3 under static load is much less than the threshold setting, that is, the stiffness performance of steel plate trough 3 is relatively excessive. The more excessive, the safer.

[0123] Then you can calculate the cost-effectiveness index CPR = (ΣSmari) / Cost;

[0124] Cost is the production cost of the proposed solution.

[0125] ΣSmari is the sum of the margin coefficients for all validation items.

[0126] In the optimization step S5, the specific analysis steps for the influence of each design variable are as follows:

[0127] The minimum change value of the m-th design variable is set to Δxm. Δxm is usually the minimum span that the design variable can achieve. For example, if the design variable is the length L of the steel plate channel 3, then Δxm can be designed to be a relatively free value such as 0.5cm or 1cm. If the design variable is the thickness of the steel plate channel 3, then according to the thickness of the steel plate that can usually be bought on the market, Δxm can only take a fixed value of 1mm.

[0128] After each design variable is individually increased by its minimum change value, the change of each verification item is calculated. This change can be regarded as the sensitivity of the verification item to the independent variable. For example, after the m-th design variable is increased by its minimum change value Δxm, the change of the n-th verification item is Δσmn. The sensitivity of the n-th verification item is ΔFmn=(Δσmn / [σ]n) / (Δxm / Rxm). ΔFmn represents the sensitivity of the n-th verification item to the m-th design variable.

[0129] Where [σ]n is the threshold of the nth verification item;

[0130] Rxm is the range of the specified range of the m-th design variable;

[0131] Calculate the percentage change in manufacturing cost after the m-th design variable increases by the minimum change value △xm, and the sensitivity of manufacturing cost △CFm=△Cm / (△xm / Rxm);

[0132] The higher these sensitivity values, the greater the impact of the corresponding design variables on the verification project or production cost; △σmn / [σ]n and △xm / Rxm are used to eliminate dimensions, thereby transforming the sensitivity calculation into a comparison between percentage changes, enabling accurate comparisons between different parameters with different dimensions.

[0133] For each design variable, calculate its impact priority;

[0134] The influence priority of the m-th design variable is Sm = Σ0.3·Smarn·△Fmn-0.1·△CFm;

[0135] 0.3·Smarn·△Fmn is the product of the margin coefficient Smarn and the sensitivity △Fmn of the nth validation item, multiplied by the weight coefficient 0.3; Σ0.3·Smarn·△Fmn represents the sum of all validation items from 1 to n after the above calculation; since the cost is a negative benefit, its weight is -0.1;

[0136] After calculating the priority of the impact of all design variables, the value of the design variable with the highest priority is adjusted.

[0137] When selecting design variables for adjustment, if adjustments are made solely based on the sensitivity ΔFmn, it is highly likely that the margin coefficient Smarn of a certain validation item will decrease, creating a safety hazard. In this method, the impact priority of each design variable is calculated by evaluating all validation items to obtain a comprehensive assessment of that variable. Furthermore, for each term in the summation, the sensitivity ΔFmn is adjusted using the margin coefficient Smarn. If the margin coefficient Smarn is too small (i.e., the adjustable space for the validation item is relatively small), then even if the sensitivity ΔFmn of that design variable is large (i.e., the change in the design variable has a significant impact on the validation item), this calculation method reduces the final impact priority value of that design variable, thereby lowering its priority for adjustment. This prioritizes adjusting design variables with a larger combined value of margin coefficient Smarn and sensitivity ΔFmn.

[0138] When adjusting design variables, it may be difficult to determine whether to increase or decrease the value of a design variable to bring it closer to the optimal value. Therefore, in this method, the design variable is counted each time it is adjusted. When the count of a design variable reaches a set limit value, the design variable is restored to its initial value and the adjustment direction is changed. For example, if the value of a design variable has been increasing, after accumulating 10 increases, the design variable is restored to its initial value. Each time the design variable needs to be adjusted later, its value is decreased.

[0139] In step S2, it is preferable to further include determining the value range of each design variable based on the obtained construction environment parameter group, and this value range needs to be verified by multiple parties to avoid generating obviously unreasonable or unimplementable solutions.

[0140] In step S2, when setting initial values ​​for multiple design variables, for any design variable, first determine the range of values ​​for that design variable, and then take the midpoint of the range to the extreme point on the safer side of the design variable as the initial value of that design variable. Taking the length L of the steel plate channel 3 as an example, generally, the smaller the length L of the steel plate channel 3, the better the rigidity of the steel plate channel 3. Although this will lead to an increase in the number of active protection bottoms and thus increase the manufacturing cost, from a safety point of view, the length L of the steel plate channel 3 needs to be relatively shorter. Assuming that the length L of the steel plate channel 3 is 60cm~100cm, then the extreme point on the safe side is 60cm, and the midpoint of the range (80cm) to the extreme point on the safer side of the design variable (60cm) is 70cm. Therefore, the initial value of the length L of the steel plate channel 3 is 70cm. This method of value selection ensures that each component of the active protection backup device is as close as possible to the safe value from the beginning. Even if this method fails to adjust some design variables, it can still guarantee the safety of the active protection backup device.

[0141] The present invention also relates to an evaluation device for an active protection backup scheme for wet joints of T-beams, comprising a storage unit and a processor. The storage unit is used to store one or more program instructions; the processor is used to run one or more program instructions to implement the steps of the above-mentioned evaluation method for active protection backup schemes of wet joints of T-beams.

[0142] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An evaluation method for an active protection backup scheme for wet joints of T-beams, characterized by the following steps: include: S1: Obtain the construction environment parameter set; S2: Set up an evaluation scheme with multiple design variables having initial values; S3: Based on the construction environment parameter set, simulate static load and wind load to verify the stiffness and strength of the scheme to be evaluated, and calculate the sway amplitude of the scheme to be evaluated under wind load to verify whether it will produce gaps that could lead to falling objects and leakage; if all the above verifications are passed, proceed to S4; otherwise, proceed to S5. S4: Calculate the production cost of the solution to be evaluated, then calculate and record the cost-effectiveness index of the solution to be evaluated; S5: Analyze the impact of changes in each design variable in the scheme to be evaluated on stiffness, strength, sway amplitude and manufacturing cost, and calculate the impact priority of each design variable in combination with the safety margin of each verification project. Adjust the design variable with the highest impact priority to form a new scheme to be evaluated. S6: Repeat S3~S5 until the set number of repetitions or the improvement of the cost-effectiveness index is very weak after multiple consecutive repetitions, and then output the solution with the highest cost-effectiveness index as the final solution. In step S1, the construction environment parameter group includes the maximum falling object weight Mdro, the maximum falling height Hdro, and the maximum vertical wind speed Vwind. In step S3, the specific steps for verifying the stiffness and strength of the scheme to be evaluated are as follows: The impact force generated by the maximum weight of the falling object at the maximum drop height is converted into the ultimate equivalent static load by using a dynamic amplification model. Calculate whether the stiffness and strength of each component in the scheme to be evaluated are within the set safety threshold under the ultimate equivalent static load. If they are, the verification is successful. The specific calculation process for the ultimate equivalent static load is as follows: Let N be the maximum number of falling objects that the proposed scheme can withstand. Ultimate equivalent static load Fload = kdro·Hdro·Mdro + N·Mdro + Moth + Mself; Where kdro is the set amplification factor; Moth is a flexible load setting; Mself is the self-weight of the scheme to be evaluated; The specific steps for calculating the swing amplitude are as follows: The area of ​​the vertical plane is S = L·H; Where L is the length of the steel plate groove in the scheme to be evaluated, and H is the depth of the steel plate groove in the scheme to be evaluated; Wind load Fwind = 0.5·P / (R·T)·Vwind²·Cd·S; Where P is the local average atmospheric pressure; R is the set gas constant; T represents the local average temperature; Cd is the set drag coefficient; Calculate the static pendulum angle θ = arcsin(Fwind / (Mself·g)); Mself is the self-weight of the scheme to be evaluated; g is the gravitational acceleration constant; Calculate the gap size Lchi = sinθ·Lrope; Where Lrope is the length of the wire rope; If the gap size Lchi is less than the set threshold, the verification is successful.

2. The evaluation method for the active protection backup scheme of T-beam wet joints according to claim 1, characterized in that, In step S4, the specific steps for calculating the cost-effectiveness index are as follows: Calculate the margin coefficient for each validation item, and denote the margin coefficient of the i-th validation item as Smari, Smari=[σ]i / σacti-1; Where [σ]i is the threshold of the i-th verification item; σacti is the actual value of the i-th verification item; Cost-effectiveness index (CPR) = (ΣSmari) / Cost; Cost is the production cost of the proposed solution. ΣSmari is the sum of the margin coefficients for all validation items.

3. The evaluation method for the active protection backup scheme of T-beam wet joints according to claim 2, characterized in that, In step S5, the specific steps for analyzing the influence of each design variable are as follows: Set the minimum change value of the m-th design variable to Δxm; After calculating the minimum change value △xm of the m-th design variable, the change of the n-th verification item is △σmn, and the sensitivity of the n-th verification item is △Fmn=(△σmn / [σ]n) / (△xm / Rxm); Where [σ]n is the threshold of the nth verification item; Rxm is the range of the specified range of the m-th design variable; Calculate the percentage change in manufacturing cost after the m-th design variable increases by the minimum change value Δxm, denoted as ΔCm. The sensitivity of manufacturing cost is ΔCFm = ΔCm / (Δxm / Rxm). For each design variable, calculate its impact priority; The influence priority of the m-th design variable is Sm = Σ0.3·Smarn·△Fmn-0.1·△CFm; After calculating the priority of the impact of all design variables, the value of the design variable with the highest priority is adjusted.

4. The evaluation method for the active protection backup scheme of T-beam wet joints according to claim 3, characterized in that, Each time a design variable is adjusted, the variable is counted. When the count of a design variable reaches the set limit value, the variable is restored to its initial value, and then the adjustment direction is changed.

5. The evaluation method for the active protection backup scheme of T-beam wet joints according to claim 1, characterized in that, Step S2 also includes determining the value range of each design variable based on the obtained construction environment parameter set.

6. The evaluation method for the active protection backup scheme of T-beam wet joints according to claim 5, characterized in that, In step S2, when setting the initial values ​​of multiple design variables, for any design variable, first determine the range of values ​​for that design variable, and then take the value of the midpoint between the midpoint of the range and the extreme point on the safer side of the design variable as the initial value of that design variable.

7. An evaluation device for an active protection and backup scheme for wet joints of T-beams, characterized in that, It includes a storage device and a processor, the storage device being used to store one or more program instructions; the processor being used to run one or more program instructions to perform the steps of the evaluation method for the active protection backup scheme of T-beam wet joints as described in any one of claims 1 to 6.

Images