CN-121706511-B - Stress analysis method for open cut tunnel of highway in high intensity area under coupled load of earthquake and falling rocks

CN121706511BCN 121706511 BCN121706511 BCN 121706511BCN-121706511-B

Abstract

The invention relates to a stress analysis method of a highway open cut tunnel in a high-intensity area under earthquake and falling stone coupling load, which belongs to the technical field of data processing analysis and comprises the following steps of introducing disaster phase coupling factors to quantify the superposition relation of earthquake kinetic energy and falling stone load pulse, adopting an earthquake falling stone time sequence coupling method to calculate the space-time evolution process of the full displacement field of the open cut tunnel surface and the steel bar strain inside the open cut tunnel to obtain the multiscale sensing condition of the open cut tunnel structure response, introducing a dynamic coupling analysis algorithm to solve the structure inertia response caused by the earthquake and the local power response caused by the falling stone load pulse, processing the multiscale power characteristics of high-frequency impact and low-frequency vibration through a mixed integration strategy, calculating the phase difference between the earthquake and the falling stone to obtain the time-gravity distribution rule of the internal structure of the open cut tunnel, and further defining the weak area of the open cut tunnel under the multi-disaster coupling effect.

Inventors

ZHENG JIQIANG
SONG LEI
ZHU SHIWEI
GONG LIMING
YANG ZHUANYUN
HUANG MIN
WAN JIAN
ZHOU XIANG
HUANG YALEI
LI JIE
FAN ANJUN
HUANG ZHENGYU
WANG MINGZHI
LIU XIAOTAO
DING KE

Assignees

四川公路工程咨询监理有限公司

Dates

Publication Date: 20260512
Application Date: 20260224

Claims (9)

1. The method for analyzing the stress of the open cut tunnel of the highway in the high intensity area under the coupling load of earthquake and falling rocks is characterized by comprising the following steps: introducing disaster phase coupling factors to quantify the superposition relation of earthquake kinetic energy and falling rock load pulse based on a dynamic finite element model of load time sequence sensitivity; the specific definition of the disaster phase coupling factor is as follows: ; Wherein, the For disaster phase coupling factor, is used for measuring the time of falling stone impact The degree of coupling with seismic energy when occurring; Is the point in time at which the falling rock impact begins; For the falling rock impact duration; A normalized seismic energy density function; Integration interval A time window representing the impact of the falling rocks during which the energy state of the earthquake is concerned; Is the total energy integral over the entire simulation time, used for normalization; The superposition of the earthquake kinetic energy and the falling rock load pulse is that the composite impact load effect of a structure or a rock mass unit on a unit area is used for describing the equivalent total energy input under the time superposition effect of the earthquake kinetic energy and the falling rock impact pulse, and specifically comprises the following steps: ; Wherein, the Equivalent total impact energy when falling rock impact and earthquake vibration jointly act on a structure or a rock mass; the quality of the falling rocks; Is the falling stone impact speed; Is the kinetic energy of falling rocks; Representing a unit pulse function or a narrow window function; Is the impact kinetic energy of falling rocks; The response capability to earthquake vibration is reflected for the effective participation quality of the structure or the rock mass; is the ground movement speed time course; Is the input seismic kinetic energy in unit time, the integration interval A time window centered on the time of impact of the falling rock; The energy integration of the earthquake is represented as continuous vibration energy input caused by the earthquake in a short time before and after falling rocks occur; a coupling enhancement term that is a nonlinear synergistic effect, In order to fall into Dan Hezai the pulse kinetic energy, Integrating kinetic energy of the earthquake in a time window; is a coupling coefficient; in a dynamic finite element model, calculating a space-time evolution process of a full displacement field of the surface of the open cut tunnel and the strain of reinforcing steel bars in the open cut tunnel by adopting an earthquake falling stone time sequence coupling method, and obtaining a multi-scale sensing condition of open cut tunnel structural response; The seismic falling rock time sequence coupling method adopted comprises the following steps in engineering practice: a first stage of earthquake generation to structural dynamic response; The second stage, the structural state after earthquake reaches the impact action of falling rocks, and then the structural response is updated, and the coupling solution is carried out through time stepping; the calculation of the full displacement field of the open cut tunnel surface is as follows: ; Wherein, the Is that The overall rigidity of the structure at the moment; is the total number of finite element units in the structure; is the first An integration domain of individual cells; is a strain-displacement matrix; Is that Is used for correlating stress with displacement; is the first A damage variable of each unit, representing the degree of material stiffness degradation; Is an initial elastic matrix; The equivalent elastic matrix of the damaged material is expressed as a rigidity reduction factor multiplied by the original rigidity; integrating the space in the unit to obtain the damage rigidity of the unit; representing the rigidity matrix of the whole structure assembled by the rigidity of all units, and representing the rigidity matrix as a nondestructive state; The space-time evolution calculation mode of the steel bar strain in the open cut tunnel is that concrete shrinkage is restrained by the steel bars or the structure, the steel bar tensile strain is reversely caused, and the restraint strain of the steel bar structure is calculated by adopting the concrete shrinkage: ; Wherein, the Is that The shrinkage strain of the concrete is restrained at the moment, and is the shrinkage strain actually generated by the concrete; Is that The elastic modulus of the concrete at any moment; is the elastic modulus of the steel bar; Is that The free shrinkage strain of the concrete at the moment; Is the bonding coefficient; A dynamic coupling analysis algorithm is introduced to solve the structural inertia response caused by earthquake and the local dynamic response caused by falling rock load pulse, and the multiscale dynamic characteristics of high-frequency impact and low-frequency vibration are processed through a hybrid integration strategy; the dynamic coupling analysis algorithm adopts a mode of combining the earthquake response time domain with the impact response frequency domain correlation to calculate: ; Wherein, the Hybrid response for the structure; Is a weight coefficient; the integral inertial response of the structure caused by earthquake; a local power transfer function for a falling rock impact; Is a frequency weight function; Is an integral range; Representing the global inertial response of the earthquake; A local dynamic response representing a falling rock impact; Based on the superposition relation of the earthquake kinetic energy and the falling stone load pulse, calculating the phase difference of the earthquake and the falling stone to obtain the time-gravity distribution rule of the internal structure of the open cut tunnel, and further determining the weak area of the open cut tunnel under the multi-disaster coupling effect.
2. The method for analyzing the stress of the highway open cut tunnel in the high intensity area under the coupling load of earthquake and falling rocks according to claim 1 is characterized in that the disaster phase coupling factor is defined as a coupling degree for measuring the energy of the earthquake when the falling rocks are impacted at a certain moment, and the total energy integration in the whole simulation time is used for calculating the total energy released by the earthquake in the time period when the falling rocks are impacted, so as to measure whether the structure is impacted during the falling rocks.
3. The method for analyzing the stress of the open cut tunnel in the high-intensity area under the coupling load of earthquake and falling rocks according to claim 1, wherein the superposition of the earthquake kinetic energy and the falling rock load pulse is that the composite impact load effect of a structure or a rock mass unit on a unit area is calculated, and the equivalent total energy input under the time superposition effect of the earthquake kinetic energy and the falling rock impact pulse is described.
4. The method for analyzing the stress of the open cut tunnel in the high intensity area under the coupling load of earthquake and falling rocks according to claim 1, wherein the calculation of the full displacement field of the surface of the open cut tunnel is to continuously model the gradual degradation of the rigidity of the structure under the action of dynamic load by introducing unit-level damage variables.
5. The method for analyzing the stress of the open cut tunnel in the high-intensity area under the coupling load of earthquake and falling rocks according to claim 1, wherein the space-time evolution process of the steel bar strain in the open cut tunnel is that concrete shrinkage is restrained by steel bars or structures, the steel bar tensile strain is reversely caused, the restrained strain of the steel bar structures is calculated by adopting the concrete shrinkage, and the actual restrained shrinkage strain of the concrete is obtained by combining the free shrinkage strain and the bonding property through the rigidity ratio of the concrete to the steel bars.
6. The method for analyzing the stress of the open cut tunnel in the high intensity area under the coupling load of the earthquake and the falling rocks according to claim 1, wherein the dynamic coupling analysis algorithm adopts a mode that an earthquake response time domain is combined with an impact response frequency domain to calculate, and the earthquake response time domain and the impact response frequency domain are overlapped, wherein the two responses are total dynamic responses after weight mixing; and combining the integral vibration of the structure caused by the earthquake with the local impact response caused by the falling rock impact in proportion to obtain the total response of the structure subjected to the earthquake response frequency domain response and the impact time domain response.
7. The method for analyzing the stress of the open cut tunnel in the high intensity area under the coupling load of earthquake and falling rocks according to claim 1, wherein for the hybrid integration strategy, the response calculated by adopting hybrid integration is compared with the actually measured response, and the structural parameters are updated through gradient descent, so that the multiscale dynamic characteristics of high-frequency impact and low-frequency vibration are described.
8. The method of claim 1, wherein the phase difference between the earthquake and the falling rock is defined as an angle of response lagging to excitation, and is used for describing the response of the single-degree-of-freedom linear damping system under simple harmonic excitation and describing the phase lag angle between the output signal and the input excitation signal.
9. The method for analyzing the stress of the open cut tunnel in the high intensity area under the coupling load of earthquake and falling rocks according to claim 1, wherein the time-gravity distribution rule is calculated by coupling the total weight load born by the open cut tunnel structure with time, wherein the calculation of the total vertical load born by the open cut tunnel structure is that the dynamic vertical stress exerted by an external rock-soil body is multiplied by the acting area and the self weight of the structure is added.

Description

Stress analysis method for open cut tunnel of highway in high intensity area under coupled load of earthquake and falling rocks Technical Field The invention belongs to the technical field of data processing analysis, and particularly relates to a stress analysis method of a highway open cut tunnel in a high intensity area under the coupling load of earthquake and falling rocks, which is used for data analysis of stress conditions. Background The open cut tunnel is used as an important protection structure for mountain roads and railways to pass through steep slopes or dangerous rock areas, and is widely applied to high-intensity earthquake areas. The main function of the system is to shield gravity geological disasters of falling rocks and collapse above the system, and meanwhile, the system is required to have enough anti-seismic performance to ensure the safe operation of traffic life lines under strong shock. The traditional open cut tunnel design is mostly based on the loading effect of a single disaster, and is assumed that the anti-falling stone design usually adopts a static force equivalent method or a simplified impact model to simplify the falling stone load into a concentrated force or an equivalent static load, and the anti-seismic design adopts a reaction spectrum method or unidirectional earthquake time course analysis according to the specification to neglect the interaction with other disasters. However, in high-intensity earthquake areas, earthquake and rockfall disasters often have space-time coupling characteristics, namely strong earthquake can induce mountain loosening and dangerous rock instability so as to cause secondary rockfall impact, and local damage caused by the rockfall impact can weaken the bearing capacity of the structure under the action of subsequent earthquake. In the prior art, the phase relation of earthquakes and falling rocks on a time domain, the interaction of energy transmission paths and the superposition effect of nonlinear response of structures are not considered, so that the evaluation of the true stress state of the open cut tunnel is poor, and potential safety hazards exist. Disclosure of Invention The invention provides a stress analysis method for a highway open cut tunnel in a high intensity area under the coupling load of earthquake and falling rocks, which is used for solving the technical problem of poor evaluation of the real stress state of the open cut tunnel. By introducing a dynamic coupling analysis algorithm, the low-frequency structure inertial response caused by earthquake and the high-frequency local dynamic response caused by falling rock impact are effectively separated and solved, and the high-efficiency and accurate processing of dynamic characteristics of different frequency scales is realized by combining a hybrid integration strategy, so that the technical problem of poor evaluation of the real stress state of the open cut tunnel is solved. In order to achieve the above purpose, the present invention is realized by the following technical scheme: the method for analyzing the stress of the open cut tunnel of the highway in the high intensity area under the coupling load of earthquake and falling rocks comprises the following steps: introducing disaster phase coupling factors to quantify the superposition relation of earthquake kinetic energy and falling rock load pulse based on a dynamic finite element model of load time sequence sensitivity; in a dynamic finite element model, calculating a space-time evolution process of a full displacement field of the surface of the open cut tunnel and the strain of reinforcing steel bars in the open cut tunnel by adopting an earthquake falling stone time sequence coupling method, and obtaining a multi-scale sensing condition of open cut tunnel structural response; A dynamic coupling analysis algorithm is introduced to solve the structural inertia response caused by earthquake and the local dynamic response caused by falling rock load pulse, and the multiscale dynamic characteristics of high-frequency impact and low-frequency vibration are processed through a hybrid integration strategy; Based on the superposition relation of the earthquake kinetic energy and the falling stone load pulse, calculating the phase difference of the earthquake and the falling stone to obtain the time-gravity distribution rule of the internal structure of the open cut tunnel, and further determining the weak area of the open cut tunnel under the multi-disaster coupling effect. Optionally, the disaster phase coupling factor is defined as a factor for measuring the coupling degree of the falling stone impact with the earthquake energy at a certain moment, and calculating the total energy released by the earthquake vibration in the time period of the falling stone impact through the total energy integral in the whole simulation time, and measuring whether the structure is impacted or not during the falling stone impact. Alt