CN107577890A - Analytical method and system for earthquake-resistant collapse capacity of underground structures - Google Patents

Abstract

The invention relates to the technical field of safety monitoring, in particular to an analysis method and system for the anti-seismic collapse ability of underground structures. The method of the invention includes: determining the seismic intensity parameter IM; Structural interaction model; build a section model of the frame structure, calculate the section bending moment-curvature, and obtain the plastic hinge parameters of the underground structure; build a soil-structure interaction plane model containing plastic hinges, and calculate the performance parameter DM of the underground structure under earthquake. The reaction acceleration method adopted in the present invention is a quasi-static anti-seismic calculation method, which uses a static method to analyze the dynamic problem, and successfully solves the problem of a large amount of machine time for one-time calculation of the soil-structure interaction model considering the dynamic boundary of the underground structure. High; the equivalent linear model is used for soil nonlinearity to avoid the influence of different nonlinear constitutive models of soil.

Description

Analytical method and system for earthquake-resistant collapse capacity of underground structures

technical field

The invention relates to the technical field of safety monitoring, in particular to an analysis method and system for the anti-seismic collapse ability of underground structures.

Background technique

Incremental Dynamic Analysis (IDA) is to multiply the acceleration of the ground motion by a series of proportional coefficients to make it a group of ground motions of different intensities. Linear dynamic time-history analysis obtains the curve of earthquake intensity and structural performance parameters, that is, IDA curve, to study the whole process of structure damage and failure under earthquake load. This method was first proposed by Bertero, and Vamvatsikos & Comell made a systematic summary and elaboration, and was adopted by FEMA35 and FEMA351 as a method for analyzing the overall collapse capacity of structures. The focus of the IDA analysis method is to select the appropriate ground motion intensity IM and structural performance parameter DM, and to select the appropriate amplitude modulation criterion in order to achieve the accuracy of the calculation results and reduce the amount of calculation.

The basic steps of the IDA analysis method are:

1. Select a representative structure and establish an elastic-plastic analysis model of the structure;

2. Select the ground motion records representing the site where the structure is located;

3. Select the ground motion intensity parameter IM and structural performance parameter DM;

4. Carry out monotonous amplitude modulation on a certain ground motion record, and obtain a series of ground motion records after amplitude modulation;

5. Single IDA curve analysis;

6. Transform the original ground motion records, repeat steps 4-5, and obtain multiple IDA curves;

7. Multiple IDA curve data processing;

8. Use the IDA results to evaluate the seismic performance of the structure.

Because the soil-structure interaction model of underground structure needs to consider the dynamic boundary, the scale is large, and a calculation will consume a lot of computer time. Soil will enter a strongly nonlinear state during earthquakes, and there are many nonlinear constitutive models of soil. To sum up, if the underground structure is analyzed by IDA, it will consume a lot of computer time, and it is even unfeasible, so it needs to be corrected.

Contents of the invention

In view of this, the present invention provides an analysis method and system for the anti-seismic collapse ability of underground structures. The reaction acceleration method adopted is a quasi-static anti-seismic calculation method, and the static method is used to analyze the dynamic problem, which successfully solves the problem of considering the dynamic boundary of the underground structure. The soil-structure interaction model of the soil-structure interaction model consumes a lot of computer time at one time, and the calculation efficiency is high; the nonlinear structure of the soil adopts an equivalent linear model to avoid the influence of different nonlinear constitutive models of the soil.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

The invention provides an analysis method for the anti-seismic collapse ability of an underground structure, comprising:

Determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located;

Construct a one-dimensional soil free field equivalent linearization model, and calculate the acceleration, equivalent shear modulus and elastic modulus of each soil layer at the moment of maximum relative displacement of the soil layers at the top and bottom of the underground structure;

Construct the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity;

Construct the section model of the frame structure member, calculate the section bending moment-curvature, and obtain the plastic hinge parameters of the underground structure;

A plane model of soil-structure interaction with plastic hinges is constructed to calculate the performance parameter DM of the underground structure under the action of earthquake.

Further, determining the earthquake intensity parameter IM includes: selecting the earthquake peak acceleration in the earthquake motion record as the earthquake intensity parameter IM.

Further, the construction of a one-dimensional soil free field equivalent linearization model includes: dividing the soil into soil layers along the depth, and adopting an equivalent linearization model for the soil.

Further, after calculating the performance parameter DM of the underground structure under the action of the earthquake, it also includes: drawing a single IDA curve.

Further, the analysis of a single IDA curve includes: calculating the dynamic response of the structure recorded by the small-amplitude-modulated earthquake motion to obtain the first DM-IM point; connecting the elastic slope of the line between the origin and the first DM-IM point Write down; continue to calculate the dynamic response of the structure recorded by the next AM earthquake motion, if the underground structure yields at this point, it is the structural yield point; continue to calculate the dynamic response of the structure recorded by the next AM earthquake motion, and obtain the next DM- IM point, if the slope between this point and the previous DM-IM point is greater than, or the interstory displacement angle of this point is greater than 10%, continue to calculate the DM-IM point under the next AM earthquake, otherwise it is considered that the structure will occur Collapse, where, 0<α<1.0, generally α is taken as 0.2.

Further, it also includes: transforming the original ground motion records to obtain multiple IDA curves and analyzing them respectively.

Further, constructing the soil-structure interaction model includes: using finite element software to construct the soil-structure interaction model.

Further, calculating the section bending moment-curvature includes: calculating the section bending moment-curvature using section capacity analysis software.

The present invention also provides an analysis system for the anti-seismic collapse ability of underground structures, including:

The seismic intensity parameter setting module is used to determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located;

One-dimensional soil free field equivalent linearization model construction calculation module, used to construct one-dimensional soil free field equivalent linearization model, and calculate the soil layers at the moment of maximum relative displacement of the soil layers at the top and bottom of the underground structure Acceleration, equivalent shear modulus and modulus of elasticity;

The first calculation module of the soil-structure interaction model is used to construct the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity;

The calculation module for constructing the section model of the frame structure member is used to construct the section model of the frame structure member, and calculate the moment-curvature of the section to obtain the plastic hinge parameters of the underground structure;

The second construction calculation module of the soil-structure interaction model is used to construct the soil-structure interaction plane model containing plastic hinges, and calculate the performance parameter DM of the underground structure under the action of earthquake.

Further, it also includes: an IDA curve drawing module, used for drawing an IDA curve.

Further, it also includes: an IDA curve analysis module, which is used to analyze the IDA curve to obtain the yield point and collapse point of the IDA curve.

Further, the first construction calculation module of the soil-structure interaction model and the second construction calculation module of the soil-structure interaction model both use finite element software.

Further, the section model building calculation module of the frame structural member adopts section capacity analysis software.

The invention provides an analysis method for the anti-seismic collapse ability of an underground structure, which has the following beneficial effects:

1. The reaction acceleration method adopted is a quasi-static anti-seismic calculation method. The static method is used to analyze the dynamic problem, and the soil-structure interaction model of the underground structure considering the dynamic boundary is successfully solved. high;

2. Equivalent linearization model is adopted for soil nonlinearity to avoid the influence of different nonlinear constitutive models of soil;

3. One-dimensional free-field equivalent linearization is used for soil nonlinearity, which can be calculated by a general program for seismic response analysis of one-dimensional site soil layers. Structural nonlinearity uses a concentrated plastic hinge model, which can be calculated by general-purpose finite element software.

The beneficial effects of the analysis system for the seismic collapse resistance of underground structures are similar to those of the analysis method for the seismic collapse resistance of underground structures, and will not be repeated here.

Description of drawings

Fig. 1 is the flow diagram of the analysis method of the anti-seismic collapse ability of the underground structure provided by the embodiment of the present invention;

Fig. 2 is the structural frame diagram of the analysis system of the anti-seismic collapse ability of the underground structure provided by the embodiment of the present invention;

Fig. 3 is the cross-section and reinforcement diagram of the underground station;

Figure 4 shows the concrete material parameters of the underground station;

Fig. 5 is soil layer parameter;

Fig. 6 is the time history of Elcentro seismic wave acceleration;

Fig. 7 is the soil equivalent linearization model;

Fig. 8 is the distribution diagram of the acceleration of each soil layer along the depth at the moment of the maximum relative displacement between the top plate and the bottom plate of the underground station;

Figure 9 is the distribution diagram of the equivalent shear modulus along the depth at the moment of maximum relative displacement between the roof and the floor of the underground station;

Figure 10 is the distribution diagram of the elastic modulus along the depth at the moment of the maximum relative displacement between the top plate and the bottom plate of the underground station;

Figure 11 is a sectional view of the column in the section capacity analysis model;

Fig. 12 is a schematic diagram of a soil-structure interaction model containing plastic hinges;

Figure 13 is a schematic diagram of the distribution of frame plastic hinges;

Figure 14 is a single IDA curve.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Exemplary embodiments of the present invention are described below in conjunction with specific circumstances:

The invention provides an analysis method for the anti-seismic collapse ability of an underground structure, which mainly includes the following steps:

Determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located;

Construct a one-dimensional soil free field equivalent linearization model, and calculate the acceleration, equivalent shear modulus and elastic modulus of each soil layer at the moment of maximum relative displacement of the soil layers at the top and bottom of the underground structure;

Construct the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity;

Construct the section model of the frame structure member, calculate the section bending moment-curvature, and obtain the plastic hinge parameters of the underground structure;

A soil-structure interaction plane model containing plastic hinges is constructed to calculate the performance parameter DM of the underground structure under earthquake motion.

Please refer to Fig. 1, Fig. 1 is the flow diagram of the analysis method of the anti-seismic collapse ability of the underground structure provided by the embodiment of the present invention; The present embodiment provides a kind of analysis method of the anti-seismic collapse ability of the underground structure, specifically comprises the following steps:

Step S101. Determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located.

In this embodiment, the peak acceleration of the earthquake in the earthquake record is selected as the earthquake intensity parameter IM.

Step S102 , constructing a one-dimensional soil free field equivalent linearized model, and calculating the acceleration, equivalent shear modulus, and elastic modulus of each soil layer at the time of maximum relative displacement of the soil layers at the top and bottom of the underground structure, respectively.

Among them, the construction of a one-dimensional soil free field equivalent linearization model includes: dividing the soil of the underground structure into soil layers along the depth, and adopting an equivalent linearization model for the soil.

Step S103, building a soil-structure interaction model, and calculating the unit internal force of the underground structure under the action of gravity.

Among them, constructing the soil-structure interaction model includes: using finite element software to construct the soil-structure interaction model.

Step S104 , building a section model of the frame structure member, calculating the section bending moment-curvature, and obtaining the plastic hinge parameters of the underground structure.

Wherein, the calculation of the section bending moment-curvature includes: using section capacity analysis software to calculate the section bending moment-curvature.

Step S105 , constructing a plane model of soil-structure interaction including plastic hinges, and calculating the performance parameter DM of the underground structure under the action of earthquake.

Step S106, draw a single IDA curve, and analyze the single IDA curve.

Among them, the analysis of a single IDA curve includes: calculating the dynamic response of the structure recorded by the small-amplitude-modulated earthquake motion, and obtaining the first DM-IM point; recording the elastic slope of the line between the origin and the first DM-IM point Do; continue to calculate the dynamic response of the structure recorded by the next AM earthquake motion, if the underground structure yields at this point, it is the structural yield point; continue to calculate the dynamic response of the structure recorded by the next AM earthquake motion, and get the next DM- IM point, if the slope between this point and the previous DM-IM point is greater than, or the interstory displacement angle of this point is greater than 10%, continue to calculate the DM-IM point under the next AM earthquake, otherwise it is considered that the structure will occur Collapse, where, 0<α<1.0, generally α is taken as 0.2.

Step S107, transforming the original ground motion records to obtain a plurality of IDA curves, and analyzing them respectively.

Embodiments of the present invention also provide an analysis system for the seismic collapse resistance of underground structures, including:

The earthquake intensity parameter setting module 201 is used to determine the earthquake intensity parameter IM according to the ground motion records of the site where the underground structure is located;

The one-dimensional soil free-field equivalent linearization model construction calculation module 202 is used to construct the one-dimensional soil free-field equivalent linearization model, and calculate the relative displacement of each soil layer at the top and bottom of the underground structure when the relative displacement is the largest. Layer acceleration, equivalent shear modulus and elastic modulus;

The first construction calculation module 203 of the soil-structure interaction model is used to construct the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity;

The frame structure component section model construction calculation module 204 is used to construct the frame structure component section model, and calculate the section bending moment-curvature, so as to obtain the plastic hinge parameters of the underground structure;

The second construction calculation module 205 of the soil-structure interaction model is used to construct a soil-structure interaction plane model including plastic hinges, and calculate the performance parameter DM of the underground structure under the action of earthquake.

Further, it also includes: an IDA curve drawing module 206 for drawing an IDA curve.

Further, it also includes: an IDA curve analysis module 207, configured to analyze the IDA curve to obtain the yield point, collapse point, etc. of the IDA curve.

Further, the first construction calculation module of the soil-structure interaction model and the second construction calculation module of the soil-structure interaction model both use finite element software. Further, the section model building calculation module of the frame structural member adopts section capacity analysis software.

The specific operation process of the analysis method for the seismic collapse resistance of underground structures provided by the embodiments of the present invention is described in detail below in conjunction with specific examples:

Taking a project: an underground station with 3 floors and 3 spans, a soil layer thickness of 70m, a structure buried depth of 10m, a Class III site, and the use of Elcentro seismic waves as an example to illustrate.

The underground station adopts a two-story, double-column, three-span concrete frame structure; a typical transverse section is taken as the design section, and the frame of the design section is composed of roof, floor, upper and lower middle plates, double middle columns, and side walls; the width of the station is 24.8m, and the height is 20.8m, of which the thickness of the roof is 0.8m, the thickness of the upper and lower middle plates is 0.4m, the thickness of the bottom plate is 1.0m, the center column is a 0.6×1.3m rectangular section, and the thickness of the side wall is 0.9m; the section and reinforcement of the station are shown in Figure 3; .

C40 is used for the concrete of the center column of the station structure, and C30 for the rest of the concrete; see Figure 4 for the concrete material parameters; see Figure 5 for the soil layer parameters, where the seismic wave is input from the bedrock; see Figure 6 for the Elcentro seismic wave records.

One-dimensional soil free field analysis is carried out, and the thickness of the soil layer is divided along the depth, and the layer thickness is taken as 1m. See Figure 7 for the equivalent linearization parameters of the soil. In the figure, the descending curve is the shear modulus attenuation curve, and the rising curve is the damping curve.

Input 1 times the Elcentro seismic wave, and calculate the acceleration, equivalent shear modulus and elastic modulus of each soil layer at the moment of maximum relative displacement between the roof and floor of the underground station, see Fig. 8, Fig. 9 and Fig. 10.

Plastic hinge moment-angle calculation. The plastic hinge moment-curvature parameters are obtained by section capacity analysis software. The thickness of the protective layer of the center column of the station is 30mm, and the HRB335 steel bar is used. The section capacity model built is shown in Figure 11.

A soil-structure interaction model with plastic hinges is constructed. The top of the soil-structure interaction model is taken from the free ground surface, the bottom boundary is a fixed boundary, and the boundaries on both sides are fixed vertical and horizontal constraints. The schematic diagram is shown in Figure 12. In order to consider nonlinearity, plastic hinges are set on the frame beam elements of the underground structure, as shown in Fig. 13.

Using the reaction acceleration method to calculate the interstory displacement angle of the underground structure, draw the IDA curve under the seismic wave, and calculate the yield point and collapse point of the IDA curve, as shown in Figure 14.

Carry out the basic steps of the IDA analysis method in the background technology afterwards:

6. Transform the original earthquake records to obtain multiple IDA curves;

7. Multiple IDA curve data processing;

8. Use the IDA results to evaluate the seismic performance of the structure.

The IDA analysis method and the IDA curve data processing therein are well-known technologies in the art and will not be described in detail.

Finally, it should also be noted that in this text, relational terms such as first and second etc. are only used to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The specific implementation methods provided by the present invention have been introduced in detail above, and the principles and implementation modes of the present invention have been explained by using specific examples in this paper. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as limiting the present invention.

Claims (9)

1. An analytical method for the seismic collapse resistance of an underground structure, characterized in that it comprises: Determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located; Construct a one-dimensional soil free field equivalent linearization model, and calculate the acceleration, equivalent shear modulus and elastic modulus of each soil layer at the moment of maximum relative displacement of the soil layers at the top and bottom of the underground structure; Construct the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity; Construct the section model of the frame structure member, calculate the section bending moment-curvature, and obtain the plastic hinge parameters of the underground structure; A plane model of soil-structure interaction with plastic hinges is constructed to calculate the performance parameter DM of the underground structure under the action of earthquake. 2. the analysis method of underground structure anti-seismic collapse ability according to claim 1, it is characterized in that, determining the seismic intensity parameter IM comprises: The peak acceleration of ground motion in the ground motion record is selected as the earthquake intensity parameter IM. 3. the analysis method of underground structure anti-seismic collapse ability according to claim 1, is characterized in that, constructs one-dimensional soil body free field equivalent linearization model, comprises: The soil is divided into soil layers along the depth, and the soil adopts an equivalent linear model. 4. the analysis method of underground structure anti-seismic collapse ability according to claim 1, it is characterized in that, after calculating the underground structure performance parameter DM under the earthquake, also comprise: Draw and analyze a single IDA curve. 5. the analysis method of underground structure anti-seismic collapse ability according to claim 4 is characterized in that, analyzing a single IDA curve comprises: Calculate the dynamic response of the structure recorded by the small-amplitude-modulated earthquake motion, and obtain the first DM-IM point; record the elastic slope of the line between the origin and the first DM-IM point; continue to calculate the next amplitude-modulated earthquake motion and record For the dynamic response of the structure, the second DM-IM point is obtained. If the underground structure yields at this point, it is the structural yield point; continue to calculate the dynamic response of the structure under the next AM earthquake record, and obtain the next DM-IM point, If the slope between this point and the previous DM-IM point is greater than, or the interstory displacement angle of this point is greater than 10%, continue to calculate the DM-IM point under the next AM earthquake, otherwise the structure will be considered to collapse, where , 0<α<1.0, generally α is taken as 0.2. 6. according to the analysis method of the earthquake-resistant collapse ability of underground structure described in claim 4 or 5, it is characterized in that, also comprises: Transform the original ground motion records to obtain multiple IDA curves and analyze them separately. 7. An analysis system for seismic collapse resistance of underground structures, characterized in that it comprises: The seismic intensity parameter setting module is used to determine the seismic intensity parameter IM according to the ground motion records of the site where the underground structure is located; One-dimensional soil free field equivalent linearization model construction calculation module, used to construct one-dimensional soil free field equivalent linearization model, and calculate the soil layers at the moment of maximum relative displacement of the soil layers at the top and bottom of the underground structure Acceleration, equivalent shear modulus and modulus of elasticity; The first building calculation module of the soil-structure interaction model is used to build the soil-structure interaction model and calculate the unit internal force of the underground structure under the action of gravity; The calculation module for constructing the section model of the frame structure member is used to construct the section model of the frame structure member, and calculate the section bending moment-curvature to obtain the plastic hinge parameters of the underground structure; The second construction calculation module of the soil-structure interaction model is used to construct the soil-structure interaction plane model containing plastic hinges, and calculate the performance parameter DM of the underground structure under the action of earthquake. 8. The analysis system of the anti-seismic collapse capability of underground structures according to claim 7, further comprising: The IDA curve drawing module is used to draw the IDA curve. 9. The analysis system of the anti-seismic collapse capability of underground structures according to claim 7, further comprising: The IDA curve analysis module is used to analyze the IDA curve and obtain the yield point and collapse point of the IDA curve.