CN115795788B - Calculation model and test method for seismic response of tower-foundation-improved foundation system - Google Patents

Abstract

A test method of a transmission tower-base-improved foundation system earthquake response calculation model comprises the steps of firstly constructing a transmission tower-transmission line-tower base physical model of an actual site, preparing a plurality of improved foundation samples, then burying the tower base model in an improved foundation layer prepared by the improved foundation samples, adding strain gauges for detecting the maximum tensile stress of the transmission line model, displacement sensors for detecting the swing amplitude of the tower tip of the transmission tower model, inclination angle sensors for detecting the inclination of the tower base model, and a laser three-dimensional scanner for detecting the average uplift degree of the improved foundation layer, inputting earthquake waves to the bottom of the improved foundation layer, constructing an earthquake response calculation model, and finally determining the optimal earthquake resistance ratio of the improved foundation according to the parameters detected in the earthquake response calculation model. The design can intuitively embody the earthquake resistance of the transmission tower system under the condition of improving foundation soil with different proportions, and determines the optimal earthquake resistance proportion of the improved foundation soil from the earthquake response angle.

Description

Calculation model and test method for seismic response of tower-foundation-improved foundation system

technical field

The invention belongs to the technical field of safety evaluation of power transmission pole-tower systems, and in particular relates to a calculation model and a test method for seismic response of a pole-tower-foundation-improved foundation system.

Background technique

my country's geological structure is complex, the seismic fault zone is widely developed, and the intensity and frequency of earthquakes are high. A large number of geological disasters and infrastructure damages caused by earthquakes occur every year. In recent years, with the expansion and construction of power grid projects, the safety of the transmission tower system under the action of earthquakes has attracted great attention. The transmission tower system is actually a tower-line-foundation coupling body, and the failure mode under the earthquake action has Many, such as uneven settlement of tower foundations, disconnection of transmission lines, tilting and collapse of towers, and damage to transmission tower systems under earthquakes will cause paralysis of transmission networks, resulting in huge economic losses and various secondary disasters. Therefore, it is of great significance to ensure the safety and stability of the transmission tower system under earthquake action.

At present, the impact of earthquake action on the transmission tower system can be weakened by improving the foundation. Since the ratio of the seismic component in the improved foundation soil to the foundation soil has a great impact on the seismic performance of the transmission tower system, the existing technology usually uses the improved foundation. Dynamic triaxial tests and other mechanical tests are used to judge the dynamic characteristics and seismic performance of the improved foundation soil, and then determine the best seismic mix ratio of the improved foundation soil, but this method cannot directly show the seismic response of the transmission tower system under the condition of different ratios of improved foundation soil The situation cannot accurately guarantee the safety and stability of the transmission tower system. Therefore, there is an urgent need for a tower-foundation-improved foundation system that can intuitively reflect the seismic performance of the transmission tower system under the condition of different ratios of improved foundation soil, and determine the best mix ratio of the improved foundation soil from the perspective of the seismic response of the transmission tower system. Earthquake response calculation model and test method.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art, and to provide a tower-foundation-improved foundation system seismic response that is more intuitive and can determine the optimal mix ratio of improved foundation soil from the perspective of the seismic response of the transmission tower system Computational models and test methods.

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

A test method for the calculation model of the seismic response of the tower-foundation-improved foundation system, the test method includes the following steps in sequence:

S1. First construct the transmission tower-transmission line-tower basic physical model of the actual site, and prepare a plurality of improved ground samples. The transmission tower-transmission line-tower basic physical model includes multiple transmission tower models and multiple transmission lines model, a plurality of tower foundation models, and then bury the tower foundation model in the improved foundation soil layer made of improved foundation samples to construct the overall model, wherein the plurality of improved foundation samples are composed of seismic components and The base soil from the actual site is mixed according to different proportions;

S2. Add strain gauges to detect the maximum tensile stress of the transmission line model on the overall model, add a displacement sensor to detect the swing amplitude of the transmission tower model tip, add an inclination sensor to detect the inclination of the foundation model of the tower, and add an average uplift to detect the improved foundation soil layer High-degree laser three-dimensional scanner, input seismic waves to the bottom of the improved foundation soil layer to build a tower-foundation-improved foundation system seismic response calculation model;

S3, using a computer to determine the improvement according to the swing amplitude of the transmission tower model tip, the maximum tensile stress of the transmission line model, the inclination of the tower foundation model, and the average uplift of the improved foundation soil layer detected in the seismic response calculation model obtained in step S2 The optimal anti-seismic ratio of the anti-seismic component in the foundation and the foundation soil from the actual site.

The step S3 comprises the following steps in turn:

S31. Using computer screening to obtain multiple seismic response calculation models that simultaneously meet the following conditions:

The detected swing amplitude of the tip of the transmission tower model ≤ the limit value of the swing amplitude of the tip of the transmission tower model;

The detected maximum tensile stress of the transmission line model ≤ the limit value of the maximum tensile stress of the transmission line model;

The detected inclination of the tower foundation model ≤ the limit value of the inclination of the tower foundation model;

S32. Using a computer to select the seismic response model with the smallest average uplift of the improved foundation soil layer from among the plurality of seismic response calculation models obtained in step S31, and use the improved foundation ratio of the seismic response calculation model with the smallest average uplift as The best anti-seismic ratio of the improved foundation in the actual site.

The limit value of the swing amplitude of the tower tip of the transmission tower model is 15mm;

The limit value of the maximum tensile stress of the transmission line model is 0.85 times of the tensile strength of the preparation material of the transmission line model;

The limit value of the inclination of the foundation model of the tower is 0.5%.

The anti-seismic components include rubber particles and cloth fibers, the percentages of which are 5-25% and 1-5% in the improved foundation sample, and the others are foundation soil from actual sites.

The cloth fibers are made from recycled waste clothes.

In step S1, the transmission tower model, transmission line model, and tower foundation model are respectively obtained by reducing the power transmission tower, tower foundation, and transmission line in the actual site by equal proportions.

Tower-foundation-improved foundation system seismic response calculation model, the seismic response calculation model includes improved foundation soil layer, computer, multiple transmission tower models, multiple transmission line models, and multiple towers corresponding to the transmission tower models The base model, the bottom of the transmission tower model is fixedly connected with the tower foundation model buried in the improved foundation soil layer, the tops of the adjacent transmission tower models are connected by transmission line models, and each transmission line model is arranged at intervals A plurality of strain gauges, displacement sensors are arranged at the spire of the transmission tower model connected with at least two transmission line models, and an inclination sensor is arranged on the base model of the transmission tower corresponding to the transmission tower model connected with at least two transmission line models, A laser three-dimensional scanner is erected on the improved foundation soil layer, and the signal output ends of the displacement sensor, strain gauge, inclination sensor, and laser three-dimensional scanner are all connected to the signal input end of the computer.

The distance between the laser three-dimensional scanner and each tower foundation model is at least five times the width of the tower foundation model.

Compared with prior art, the beneficial effect of the present invention is:

In the test method of the seismic response calculation model of the tower-foundation-improved foundation system of the present invention, first construct the transmission tower-transmission line-tower foundation physical model of the actual site and prepare a plurality of improved foundation samples, the physical model includes a plurality of transmission towers model, multiple transmission line models, and multiple tower foundation models, and then bury the tower foundation model in the improved foundation soil layer made of improved foundation samples, add strain gauges to detect the maximum tensile stress of the transmission line model, and add a transmission line to detect the maximum tensile stress A displacement sensor for the swing amplitude of the tower model tip, an inclination sensor for detecting the inclination of the tower foundation model, and a laser three-dimensional scanner for detecting the average uplift of the improved foundation soil layer are added, and seismic waves are input to the bottom of the improved foundation soil layer to construct the tower-foundation -Improve the calculation model of the seismic response of the foundation system, and finally use the computer to detect the vibration amplitude of the tower model of the transmission tower model, the maximum tensile stress of the transmission line model, the inclination of the foundation model of the tower, and the average uplift of the improved foundation soil layer by computer , jointly determine the optimal seismic ratio of the improved foundation. In this design, the swing amplitude of the tower tip of the transmission tower model, the maximum tensile stress of the transmission line model, and the inclination of the foundation model of the tower can be intuitively reflected in the transmission tower system. The degree of deformation of the foundation of power transmission lines and towers under the action of the earthquake, according to the average uplift of the improved foundation soil layer obtained through the detection, clearly shows the uplift of the improved foundation soil layer, and selects that under the same level of earthquake action, the degree of deformation meets the standard and the degree of uplift is the smallest The improved foundation ratio of the actual site is used as the best seismic ratio of the improved foundation on the actual site to ensure the safety and stability of the transmission tower system to the greatest extent. Therefore, the present invention can visually reflect the anti-seismic performance of the transmission tower system under the condition of different ratios of improved foundation soil, and determine the best anti-seismic ratio of the improved foundation soil from the perspective of the seismic response of the transmission tower system.

Description of drawings

Fig. 1 is a structural schematic diagram of the seismic response calculation model of the tower-foundation-improved foundation system in the present invention.

Fig. 2 is a control schematic diagram of the present invention.

Fig. 3 is the detection result of the maximum tensile stress of the transmission line model of the 15 earthquake response calculation models in the first embodiment.

Fig. 4 is the inclination detection result of the tower foundation model of the 15 seismic response calculation models in the first embodiment.

Fig. 5 is the detection result of the tip swing amplitude of the transmission tower model of the 15 earthquake response calculation models in the first embodiment.

FIG. 6 shows the detection results of the average heaving degree of the improved foundation soil layer of the three seismic response calculation models screened in step S4 in Example 1.

In the figure, the improved foundation soil layer 1, rubber particles 11, cloth fiber 12, computer 2, transmission tower model 3, transmission line model 4, tower foundation model 5, strain gauge 6, displacement sensor 7, inclination sensor 8, laser three-dimensional scanning Instrument 9.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Referring to Fig. 1 to Fig. 6, the test method of the tower-foundation-improved foundation system seismic response calculation model, the test method includes the following steps in turn:

S1. First construct the transmission tower-transmission line-tower basic physical model of the actual site, and prepare a number of improved foundation samples. The transmission tower-transmission line-tower basic physical model includes multiple transmission tower models 3. Multiple power transmission line model 4, a plurality of tower foundation models 5, and then the tower foundation model 5 is buried in the improved foundation soil layer 1 made of the improved foundation sample to construct the overall model, wherein the plurality of improved foundation samples are all It is obtained by mixing the anti-seismic components and the foundation soil from the actual site in different proportions;

S2, add the strain gage 6 that detects the maximum tensile stress of the transmission line model 4 on the overall model, add the displacement sensor 7 that detects the swing amplitude of the transmission tower model 3 spire, add the inclination sensor 8 that detects the inclination of the base model 5 of the tower, and add detection The laser three-dimensional scanner 9 for the average uplift of the improved foundation soil layer 1 inputs seismic waves to the bottom of the improved foundation soil layer 1 to construct a tower-foundation-improved foundation system seismic response calculation model;

S3, using the computer 2 according to the transmission tower model 3 tip swing amplitude detected in the seismic response calculation model obtained in step S2, the maximum tensile stress of the transmission line model 4, the slope of the tower foundation model 5, and the average value of the improved foundation soil layer 1 Uplift, to determine the best anti-seismic ratio of the anti-seismic component in the improved foundation and the subsoil from the actual site.

The step S3 comprises the following steps in turn:

S31. Use the computer 2 to screen and obtain multiple earthquake response calculation models that simultaneously meet the following conditions:

The detected swing amplitude of the tip of the transmission tower model 3 ≤ the limit value of the swing amplitude of the tip of the transmission tower model 3;

The detected maximum tensile stress of the transmission line model 4 ≤ the limit value of the maximum tensile stress of the transmission line model 4;

The detected inclination of the tower foundation model 5 ≤ the limit value of the inclination of the tower foundation model 5;

S32. Using the computer 2 to select the seismic response model with the smallest average uplift of the improved foundation soil layer 1 from the multiple seismic response calculation models obtained in step S31, and use the improved foundation configuration of the seismic response calculation model with the smallest average uplift The ratio is the best anti-seismic ratio of the improved foundation in the actual site.

The limit value of the swing amplitude of the tower tip of the transmission tower model 3 is 15mm;

The limit value of the maximum tensile stress of the transmission line model 4 is 0.85 times the tensile strength of the material prepared by the transmission line model 4;

The limit value of the inclination of the tower foundation model 5 is 0.5%.

The anti-seismic components include rubber particles 11 and cloth fibers 12. The percentages of the rubber particles 11 and cloth fibers 12 in the improved foundation sample are 5-25% and 1-5% respectively, and the others are obtained from the actual site. base soil.

The cloth fiber 12 is made from recycled waste clothes.

In step S1, the transmission tower model 3, the transmission line model 4, and the tower foundation model 5 are respectively obtained by scaling down the transmission towers, tower foundations, and transmission lines in the actual site.

Tower-foundation-improved foundation system seismic response calculation model, said seismic response calculation model includes improved foundation soil layer 1, computer 2, multiple transmission tower models 3, multiple transmission line models 4, and one-to-one correspondence with transmission tower models 3 A plurality of tower foundation models 5 are set, the bottom of the transmission tower model 3 is fixedly connected to the tower foundation model 5 buried in the improved foundation soil layer 1, and the tops of adjacent transmission tower models 3 are connected by a transmission line model 4 , a plurality of strain gauges 6 are arranged at intervals on each transmission line model 4, and a displacement sensor 7 is arranged at the spire of the transmission tower model 3 connected with at least two transmission line models 4, and is connected with at least two transmission line models An inclination sensor 8 is arranged on the corresponding tower foundation model 5 of the power transmission tower model 3 of 4, a laser three-dimensional scanner 9 is erected on the improved foundation soil layer 1, the displacement sensor 7, the strain gauge 6, the inclination sensor 8, The signal output terminals of the laser three-dimensional scanner 9 are all connected with the signal input terminals of the computer 2 .

The distance between the laser three-dimensional scanner 9 and each tower foundation model 5 is at least five times the width of the tower foundation model 5 .

Example 1:

Refer to Figure 1 and Figure 2, taking the Enyu Line transmission tower system in western Hubei as the test object, a tower-foundation-improved foundation system seismic response calculation model, including improved foundation soil layer 1, computer 2, and three transmission tower models 3. Two transmission line models 4, three base tower models 5 corresponding to the transmission tower model 3. , tower foundation, and transmission lines are obtained through equal proportion reduction, and the reduction ratio is 1/20. The transmission tower model 3 is made of the same material as the transmission tower in the actual site, which is Q345 steel. The transmission line model 4 is the same as that in the actual site. The production materials of the transmission lines are the same, all are steel-cored aluminum conductors with a diameter of 5mm. The base model 5 of the pole tower is the same as the production material of the transmission lines in the actual site, which is C30 concrete. The bottom of the transmission pole model 3 is buried in the The tower foundation model 5 in the improved foundation soil layer 1 is fixedly connected, and the tops of the adjacent power transmission tower models 3 are connected through the transmission line model 4, and a plurality of strain gauges 6 are arranged at intervals on each transmission line model 4, adjacent to each other. The distance between the strain gauges 6 is 10cm, and a displacement sensor 7 is arranged at the spire of the transmission tower model 3 connected with two transmission line models 4. An inclination sensor 8 is arranged on the base model 5, and a laser three-dimensional scanner 9 is set up on the improved foundation soil layer 1, and the distance between the laser three-dimensional scanner 9 and each tower base model 5 is controlled within five times of the width of the base model 5 of the tower. times and above, the signal output terminals of the displacement sensor 7, the strain gauge 6, the inclination sensor 8, and the laser three-dimensional scanner 9 are all connected with the signal input terminals of the computer 2;

Based on the test method of the above-mentioned tower-foundation-improved foundation system seismic response calculation model, the following steps are followed in turn:

S1. First construct the transmission tower-transmission line-tower basic physical model of the actual site, and prepare a number of improved foundation samples. The transmission tower-transmission line-tower basic physical model includes three transmission tower models 3, two power transmission Line model 4, three tower foundation models 5, the multiple improved foundation samples are obtained by mixing the anti-seismic components and foundation soil from the actual site in different proportions, and then the tower foundation models 5 are buried in the improved foundation test In the improved foundation soil layer 1 made by the sample, to build the overall model;

Wherein, the anti-seismic components include rubber particles 11 and cloth fibers 12, the particle diameter of the rubber particles 11 is 3 mm, the cloth fibers 12 are made from recycled waste clothes, and the rubber particles 11 are used in improving the foundation sample The percentage content in is set to 5%, 10%, 15%, 20%, 25%, the percentage content of the cloth fiber 12 in the improved foundation sample is set to 1%, 3%, 5%, and the rest are from the actual For the foundation soil of the site, a total of 15 improved foundation samples were prepared according to the different ratios of rubber particles 11 and cloth fibers 12 in the improved foundation samples, and a total of 15 overall models were constructed based on the 15 improved foundation samples;

S2, add the strain gage 6 that detects the maximum tensile stress of the transmission line model 4 on the overall model, add the displacement sensor 7 that detects the swing amplitude of the transmission tower model 3 spire, add the inclination sensor 8 that detects the inclination of the base model 5 of the tower, and add detection The laser three-dimensional scanner 9 with the average uplift of the improved foundation soil layer 1 inputs seismic waves to the bottom of the improved foundation soil layer 1 to construct a seismic response calculation model for the tower-foundation-improved foundation system, which is constructed based on the 15 overall models obtained in step S1 A total of 15 seismic response calculation models were obtained;

S3. Use the computer 2 to select an earthquake response calculation model that satisfies the following conditions at the same time from 15 seismic response calculation models:

The detected swing range of the tip of the transmission tower model 3 is ≤15mm;

The detected maximum tensile stress of the transmission line model 4 is ≤ 0.85 times the tensile strength of the material prepared by the transmission line model 4, and 0.85 times the tensile strength of the material prepared by the transmission line model 4 is 20 MPa;

The detected inclination of tower foundation model 5 is ≤0.5%;

The detection results of the maximum tensile stress of the transmission line model 4, the inclination of the tower foundation model 5, and the tip swing amplitude of the transmission tower model 3 in the 15 seismic response calculation models are shown in Figure 3-Figure 5 respectively, and are screened according to Figure 3-Figure 5 A total of 3 seismic response calculation models were obtained. In the 3 seismic response calculation models, the proportions of the improved foundation soil were 3% of cloth fiber and 10% of rubber particles, 3% of cloth fiber and 15% of rubber particles, 5% of cloth fiber and Rubber particles 10%;

S4. Using the computer 2 to select the seismic response model with the smallest average uplift of the improved foundation soil layer 1 from the 3 seismic response calculation models screened in step S4, the average uplift of the improved foundation soil layer 1 of the 3 seismic response calculation models According to Fig. 6, it can be seen that the average heave degree of the seismic response calculation model is the smallest when the proportion of improved foundation soil is 3% cloth fiber and 15% rubber particles. Therefore, 3% cloth fiber and 15% rubber particles 15% is used as the optimal anti-seismic ratio for the improved foundation of the Enyu line transmission tower system in western Hubei.

Claims (7)

1. The test method of the earthquake response calculation system of the tower-foundation-improved foundation system is characterized by comprising the following steps of:

the test method sequentially comprises the following steps:

s1, firstly constructing a transmission tower-transmission line-tower foundation physical model of an actual field, and preparing a plurality of improved foundation samples, wherein the transmission tower-transmission line-tower foundation physical model comprises a plurality of transmission tower models (3), a plurality of transmission line models (4) and a plurality of tower foundation models (5), and then burying the tower foundation models (5) in an improved foundation layer (1) prepared from the improved foundation samples to construct an integral model, and the improved foundation samples are obtained by mixing anti-seismic components with foundation soil from the actual field according to different proportions;

s2, adding strain gauges (6) for detecting the maximum tensile stress of a transmission line model (4) on the whole model, adding displacement sensors (7) for detecting the swing amplitude of the tower tip of a transmission tower model (3), adding inclination angle sensors (8) for detecting the inclination angle of a tower foundation model (5), adding a laser three-dimensional scanner (9) for detecting the average uplift degree of an improved foundation layer (1), and inputting seismic waves to the bottom of the improved foundation layer (1) to construct a tower-foundation-improved foundation system seismic response calculation system;

s3, determining the optimal anti-seismic proportion of the anti-seismic component in the improved foundation and the foundation soil from the actual field by using a computer (2) according to the swing amplitude of the tower tip of the transmission tower model (3), the maximum tensile stress of the transmission tower model (4), the gradient of the tower foundation model (5) and the average degree of elevation of the improved foundation soil layer (1) which are detected in the earthquake response calculation system obtained in the step S2;

the step S3 sequentially comprises the following steps:

s31, screening by using a computer (2) to obtain a plurality of earthquake response computing systems meeting the following conditions simultaneously:

the detected swing amplitude of the tower tip of the transmission tower model (3) is less than or equal to the limit value of the swing amplitude of the tower tip of the transmission tower model (3);

the maximum tensile stress of the detected power transmission line model (4) is less than or equal to the limit value of the maximum tensile stress of the power transmission line model (4);

the detected gradient of the tower foundation model (5) is less than or equal to the limit value of the gradient of the tower foundation model (5);

s32, selecting a seismic response computing system with the minimum average rising degree of the improved foundation layer (1) from the plurality of seismic response computing systems obtained in the step S31 by utilizing the computer (2), and taking the improved foundation proportion of the seismic response computing system with the minimum average rising degree as the optimal earthquake resistant proportion of the improved foundation of the actual field.

2. The method for testing a system for calculating the earthquake response of a tower-foundation-modified foundation system according to claim 1, wherein:

the limit value of the swing amplitude of the tower tip of the transmission tower model (3) is 15mm;

the limit value of the maximum tensile stress of the power transmission line model (4) is 0.85 times of the tensile strength of the preparation material of the power transmission line model (4);

the limit value of the inclination of the tower foundation model (5) is 0.5 percent.

3. The method for testing a system for calculating the earthquake response of a tower-foundation-modified foundation system according to claim 1 or 2, wherein:

the anti-seismic component comprises rubber particles (11) and cloth fibers (12), wherein the percentage content of the rubber particles (11) and the cloth fibers (12) in the improved foundation sample is 5-25% and 1-5% respectively, and the other is foundation soil from an actual field.

4. A method of testing a system for calculating the seismic response of a tower-foundation-modified foundation system according to claim 3, wherein:

the cloth fiber (12) is manufactured by recycling waste clothes.

5. The method for testing a system for calculating the earthquake response of a tower-foundation-modified foundation system according to claim 1 or 2, wherein:

in step S1, the transmission tower model (3), the transmission line model (4) and the tower foundation model (5) are respectively obtained by reducing the transmission tower, the tower foundation and the transmission line in equal proportion in an actual field.

6. A tower-foundation-modified foundation system seismic response calculation system applied to the test method of any one of claims 1-5, characterized in that:

the earthquake response computing system comprises an improved foundation soil layer (1), a computer (2), a plurality of transmission tower models (3), a plurality of transmission tower foundation models (4) and a plurality of transmission tower foundation models (5) which are arranged in a one-to-one correspondence manner with the transmission tower models (3), wherein the bottom of the transmission tower models (3) is fixedly connected with the transmission tower foundation models (5) buried in the improved foundation soil layer (1), the tops of the adjacent transmission tower models (3) are connected through the transmission tower models (4), a plurality of strain gauges (6) are uniformly arranged on each transmission tower model (4) at intervals, displacement sensors (7) are arranged at the tower tip of the transmission tower models (3) which are at least connected with the two transmission tower models (4), inclination sensors (8) are arranged on the transmission tower foundation models (5) which are corresponding to the transmission tower models (3) which are at least connected with the two transmission tower models (4), a laser three-dimensional scanner (9) is arranged on the improved foundation soil layer (1), and the displacement sensors (7), the strain gauges (6) and the strain gauges (8) are connected with the output ends of the laser three-dimensional scanner (2).

7. The tower-foundation-modified foundation system seismic response calculation system of claim 6, wherein:

the distance between the laser three-dimensional scanner (9) and each tower foundation model (5) is at least five times the width of the tower foundation model (5).