A method for evaluating tunnel structure toughness considering the time-dependent characteristics of soft rock

Abstract

The present invention discloses a method for evaluating the toughness of tunnel structures that considers the aging characteristics of soft rock. The method calculates weight coefficients and performance indicators, plots a three-dimensional scatter plot using the performance indicator data, and performs three-dimensional surface fitting to obtain a surface diagram of the spatiotemporal evolution of the lining performance indicators. The method also calculates the volume enclosed by the spatiotemporal evolution surface of the lining performance indicators that considers the aging deformation of the surrounding rock, the time axis, and the space axis, and the volume enclosed by the spatiotemporal evolution surface of the lining performance indicators that does not consider the aging deformation of the surrounding rock, and compares the two to obtain a toughness index. The overall toughness index of the internal and external lining is then calculated based on the obtained toughness index. Compared with the prior art, the method of evaluating the toughness of tunnel structures that considers the aging characteristics of soft rock of the present invention fully considers the spatiotemporal evolution of the stress on the lining by considering the aging deformation of the surrounding rock, and can provide a reliable calculation method for reasonably evaluating the long-term performance of the lining.

Description

Technical Field

[0001] The present invention relates to the technical field of underground tunnel support engineering, and in particular to a tunnel structure toughness evaluation method taking into account the aging characteristics of soft rock. Background Art

[0002] In soft rock underground projects, due to the high ground stress in the environment and the strong rheological properties of the weak surrounding rock, the time-dependent deformation of the surrounding rock poses a huge hidden danger to the long-term performance maintenance and safe operation and maintenance of the lining. Traditional lining performance evaluation methods are mostly guided by the safety factor method, which calculates the ratio between the bearing capacity and the bearing capacity of the lining after the lining structure is stabilized. On the one hand, this evaluation method mostly uses the safety factor of the lining's dangerous points as the evaluation standard, which is difficult to reflect the overall non-uniformity of the lining's stress. On the other hand, this evaluation method selects the final state of the lining after elastic-plastic equilibrium, which is difficult to reflect the lining's response process to time-dependent loads, and it is even more impossible to evaluate the lining's ability to resist external disturbances during service.

[0003] Resilience management is gaining more and more attention in today's world, such as seismic resilience, urban resilience, ecological resilience, and social resilience. Resilience is defined as the ability of a structure to recover after external disturbances. In underground engineering, it is mainly used to evaluate the mechanical response of tunnel structures under seismic load conditions. Its connotation mainly includes robustness, redundancy, rapidity, and resourcefulness. With the development of underground engineering, more and more tunnel projects have encountered problems with lining damage during operation. Considering the resilience control under the conditions of time-dependent deformation of surrounding rock, it has received more and more attention. However, the existing resilience assessment methods are difficult to directly apply to tunnel conditions with time-dependent deformation of surrounding rock.

[0004] Therefore, how to provide a tunnel structure toughness assessment method that takes into account the aging characteristics of soft rock, so that it can take into account the aging deformation of the surrounding rock and achieve the technical effect of providing technical support for the toughness support design of soft rock tunnels, is a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] In view of the problem of lining damage in the operation period of more and more tunnel projects in the prior art, the technical problem to be solved by the present invention is to provide a tunnel structure toughness assessment method taking into account the aging characteristics of soft rock, so as to provide technical support for the toughness support design of soft rock tunnels.

[0006] To achieve the above-mentioned object, the present invention provides a method for evaluating the toughness of a tunnel structure taking into account the aging characteristics of soft rock. The method comprises the following steps: S1. Based on actual on-site conditions, selecting a control index that affects the safety performance of the lining and obtaining an allowable value of the selected control index;

[0007] S2. Calculate the safety degree based on the obtained allowable value of the control index, calculate the weight coefficient of different control indexes according to the weight ratio of the safety degree, and obtain the performance index of the lining at different positions and at different times according to the performance index calculation formula; S3. Draw a three-dimensional scatter plot based on the obtained performance index data of the lining at different positions and at different times, and perform three-dimensional surface fitting. According to the integral calculation of the three-dimensional surface, the volume enclosed by the spatiotemporal evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock and the time axis and space axis is obtained; S4. Calculate the spatiotemporal evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock without considering the time-dependent deformation of the surrounding rock The volume enclosed by the time-space evolution surface of the lining performance index with the time axis and the space axis is calculated, and the volume enclosed by the time-space evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock and the volume enclosed by the time-space evolution surface of the lining performance index without considering the time-dependent deformation of the surrounding rock is compared with the volume enclosed by the time-space evolution surface of the lining performance index without considering the time axis and the space axis to obtain the toughness index of the lining at different times; S5. Based on the obtained toughness index of the lining at different times, the toughness index of the entire internal and external lining at different times is calculated by the calculation formula of the overall toughness index of the internal and external lining.

[0008] In the first aspect, in S1, the selected control indicators include lining concrete stress, steel bar stress, lining deformation and crack opening; the allowable values ​​of the control indicators include allowable values ​​of the control indicators inside the lining and allowable values ​​of the control indicators outside the lining.

[0009] In the first aspect, the weight coefficient includes the lining internal weight coefficient α i内 and lining external weight coefficient α i外 , the weight coefficient α inside the lining i内 The calculation formula is as follows:

[0010]

[0011] Among them, θ 内 To characterize the internal position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is time; P i内 (θ 内 ,t) is the i-th control index inside the lining; α i内 is the weight coefficient of the i-th control index inside the lining; n is the total number of control indexes selected inside the lining;

[0012] The weight coefficient α of the external i外 The calculation formula is as follows:

[0013]

[0014] Among them, θ 外 To characterize the parameters of the external position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is the time; P i外 (θ外 ,t) is the ith control index of the lining exterior; α i外 is the weight coefficient of the i-th control index of the lining exterior; n is the total number of control indexes selected for the lining exterior.

[0015] In the first aspect, the performance index includes the lining internal performance index Q 内 (θ 内 ,t) and lining external performance index Q 外 (θ 外 ,t), the lining internal performance index Q 内 (θ 内 ,t) is calculated as follows:

[0016]

[0017] Among them, Q 内 (θ 内 ,t) is the internal performance index of the lining; n is the total number of selected control indicators;

[0018] The lining external performance index Q 外 (θ 外 ,t) is calculated as follows:

[0019]

[0020] Among them, Q 外 (θ 外 , t) is the external performance index of the lining; n is the total number of selected control indicators.

[0021] In the first aspect, in S1, the control indicators affecting the safety performance of the lining are selected based on site conditions and engineering experience; wherein, when the selected control indicator is stress, the Pi inner (θ inner, t) represents the stress evolution law at different positions inside the lining over time, and the Pi outer (θ outer, t) represents the stress evolution law at different positions outside the lining over time; or, when the selected control indicator is deformation, the Pi inner (θ inner, t) represents the deformation evolution law at different positions inside the lining over time, and the Pi outer (θ outer, t) represents the deformation evolution law at different positions outside the lining over time.

[0022] In the first aspect, the volume enclosed by the temporal and spatial evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock, the time axis and the space axis includes the volume V enclosed by the temporal and spatial evolution surface of the lining internal performance index, the time axis and the space axis. 内(t1) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t1) The volume V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis is (t1)The calculation formula is as follows:

[0023]

[0024] Among them, V 内(t1) is the volume enclosed by the time axis and space axis of the surface of the temporal and spatial evolution of the internal performance index of the lining at time t1 when considering the time-dependent deformation of the surrounding rock; θ 内max is the maximum value of the internal parameters of the lining space, when θ 内 is the angle, then θ 内max is 360°;

[0025] The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis (t1) The calculation formula is as follows:

[0026]

[0027] Among them, V 外(t1) is the volume enclosed by the time axis and space axis of the spatiotemporal evolution surface of the lining external performance index at time t1 when considering the time-dependent deformation of the surrounding rock; θ 外max is the maximum value of the external parameter of the lining space, when θ 外 is the angle, then θ 外max It is 360°.

[0028] In the first aspect, the volume enclosed by the temporal and spatial evolution surface of the lining performance index without considering the aging deformation of the surrounding rock, the time axis and the space axis includes the volume V enclosed by the temporal and spatial evolution surface of the lining internal performance index, the time axis and the space axis. 内(t0) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0) The area V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis is 内(t0) The calculation formula is as follows:

[0029]

[0030] Among them, V 内(t0) Q is the volume enclosed by the time-space evolution surface of the lining internal performance index when the time-dependent deformation of the surrounding rock is not considered; 内 (θ 内 ,t0) is the performance index of the lining interior at the initial time t0;

[0031] The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0) The calculation formula is as follows:

[0032]

[0033] Among them, V 外(t0) Q is the volume enclosed by the time-space evolution surface of the lining external performance index when the time-dependent deformation of the surrounding rock is not considered, the time axis, and the space axis; 外 (θ 外 ,t0) is the performance index of the lining exterior at the initial moment t0.

[0034] In the first aspect, the toughness index of the lining includes the toughness index Re inside the lining. 内 (t) and the toughness index Re of the lining exterior 外 (t), the toughness index Re inside the lining 内 The calculation formula of (t) is as follows:

[0035]

[0036] Among them, Re 内 (t) is the toughness index of the lining at time t;

[0037] The toughness index Re of the lining exterior 外 The calculation formula of (t) is as follows:

[0038]

[0039] Among them, Re 外 (t) is the toughness index of the lining exterior at time t.

[0040] In the first aspect, the calculation formula for the overall toughness index of the internal and external lining is as follows:

[0041] Re(t)=Re 内 (t)×Re 外 (t);

[0042] Among them, Re(t) is the toughness index of the entire internal and external lining at time t.

[0043] In the first aspect, in said S3, a three-dimensional scatter plot is drawn based on the obtained performance index data of the lining at different positions and at different times, and a three-dimensional surface fitting is performed to reflect the response of the lining to long-term loads.

[0044] Beneficial effects:

[0045] The present invention provides a tunnel structure toughness assessment method that considers the aging characteristics of soft rock. The method takes into account the aging deformation of the surrounding rock, calculates the weight coefficient and performance index, draws a three-dimensional scatter plot based on the performance index data at different positions and times of the lining, and performs three-dimensional surface fitting to obtain a spatiotemporal evolution surface diagram of the lining performance index. The method also calculates the volume enclosed by the spatiotemporal evolution surface of the lining performance index that takes into account the aging deformation of the surrounding rock, the time axis, and the space axis, and obtains the volume enclosed by the spatiotemporal evolution surface of the lining performance index that does not consider the aging deformation of the surrounding rock, the time axis, and the space axis. By comparing the two, the toughness index of the lining at different times is obtained. The toughness index of the entire internal and external lining at different times is then calculated based on the obtained toughness index of the lining at different times. This method provides technical support for the future toughness support design of soft rock tunnels. The specific advantages are as follows:

[0046] 1. The present invention's tunnel structural toughness assessment method, which considers the aging characteristics of soft rock, more comprehensively characterizes the stress state of the lining compared to existing performance assessment methods, effectively reflecting the unevenness of the lining stress. Ultimately, it generates a comprehensive indicator, or performance index, that reflects lining performance. The performance index ranges from 0 to 1, with 1 representing optimal performance and 0 representing the worst. The resulting performance index parameters are concise, facilitating better understanding and calculation of lining safety performance by designers and researchers.

[0047] 2. Compared to the existing safety factor method, the present invention's tunnel structural toughness assessment method, which considers the aging characteristics of soft rock, incorporates the temporal evolution of lining performance indicators, namely, a spatiotemporal evolution surface of lining performance indicators. This method effectively reflects the lining's response to long-term loads, enabling the calculation of the lining's toughness at different times, thereby assessing the lining's ability to resist external loads during tunnel operation.

[0048] 3. The present invention provides a tunnel structural toughness assessment method that considers the aging characteristics of soft rock. The proposed performance index calculation method can comprehensively reflect the impact of different lining performance parameters. The proposed performance parameter weight coefficient calculation method can automatically adjust the weight coefficients based on the safety of different control indicators. This calculation method not only ensures that the sum of all weight coefficients is 1, but also has the function of automatically assigning higher weight coefficients to control indicators that have a controlling effect on lining safety.

[0049] 4. Compared to existing toughness assessment methods, the present invention's tunnel structure toughness assessment method, which considers the aging characteristics of soft rock, not only considers the temporal and spatial evolution of lining performance indicators but also the influence of initial lining performance indicators. The calculated toughness index ranges from 0 to 1, with 1 representing the highest lining toughness and 0 representing the lowest. The resulting toughness index is concise, easy to understand, and has a clear physical meaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 This is a flow chart of a method for evaluating the toughness of a tunnel structure taking into account the aging characteristics of soft rock according to the present invention;

[0052] Figure 2 In the present invention, a method for evaluating the toughness of a tunnel structure considering the aging characteristics of soft rock is used. When θ 内 When θ is the included angle, 内 markings on the inside of the lining;

[0053] Figure 3 In the present invention, a method for evaluating the toughness of a tunnel structure considering the aging characteristics of soft rock is used. When θ 外 When θ is the included angle, 外 markings on the outside of the lining;

[0054] Figure 4 It is a spatiotemporal evolution surface of the external performance index of the lining in a tunnel structure toughness evaluation method considering the aging characteristics of soft rock according to the present invention;

[0055] Figure 5 It is a spatiotemporal evolution surface of internal performance indicators of lining in a tunnel structure toughness evaluation method taking into account the aging characteristics of soft rock according to the present invention.

[0056] Reference numerals:

[0057] 1. Lining; 2. Spatiotemporal evolution surface of lining external performance indicators without considering the time-dependent deformation of surrounding rock; 3. Spatiotemporal evolution surface of lining external performance indicators with considering the time-dependent deformation of surrounding rock; 4. Spatiotemporal evolution surface of lining internal performance indicators without considering the time-dependent deformation of surrounding rock; 5. Spatiotemporal evolution surface of lining internal performance indicators with considering the time-dependent deformation of surrounding rock. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this invention.

[0059] Example 1

[0060] like Figures 1 to 5As shown, the present embodiment 1 provides a method for evaluating the toughness of a tunnel structure taking into account the aging characteristics of soft rock, and the method for evaluating the toughness of a tunnel structure taking into account the aging characteristics of soft rock includes the following steps: S1, based on the actual conditions on site, selecting a control index that affects the safety performance of the lining, and obtaining an allowable value of the selected control index; S2, performing safety calculation based on the obtained allowable value of the control index, calculating the weight coefficient of different control indicators according to the weight ratio of the safety, and obtaining the performance index of the lining at different positions and at different times according to the performance index calculation formula; S3, drawing a three-dimensional scatter plot based on the obtained performance index data of the lining at different positions and at different times, and performing three-dimensional surface fitting, and calculating the integral of the three-dimensional surface according to the integral of the three-dimensional surface. Obtain the volume enclosed by the time-space evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock, the time axis and the space axis; S4. Calculate the volume enclosed by the time-space evolution surface of the lining performance index not considering the time-dependent deformation of the surrounding rock, the time axis and the space axis, and compare the volume enclosed by the time-space evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock, the time axis and the space axis with the volume enclosed by the time-space evolution surface of the lining performance index not considering the time-dependent deformation of the surrounding rock, to obtain the toughness index of the lining at different times; S5. Based on the obtained toughness index of the lining at different times, the toughness index of the entire internal and external lining at different times is calculated using the calculation formula for the overall toughness index of the internal and external lining.

[0061] The present invention provides a tunnel structure toughness evaluation method considering the aging characteristics of soft rock. The method takes into account the aging deformation of the surrounding rock, calculates the weight coefficient and performance index, draws a three-dimensional scatter plot based on the performance index data at different positions and times of the lining, and performs three-dimensional surface fitting to obtain a spatiotemporal evolution surface diagram of the lining performance index. The method also calculates the volume enclosed by the spatiotemporal evolution surface of the lining performance index considering the aging deformation of the surrounding rock, the time axis, and the space axis, and obtains the volume enclosed by the spatiotemporal evolution surface of the lining performance index without considering the aging deformation of the surrounding rock, and obtains the volume enclosed by the spatiotemporal evolution surface of the lining performance index without considering the aging deformation of the surrounding rock. The method compares the two to obtain the toughness index of the lining at different times. The method then calculates the toughness index of the entire internal and external lining at different times based on the obtained toughness index of the lining at different times. The method fully considers the spatiotemporal evolution law of the lining stress, provides a reliable calculation method for reasonably evaluating the long-term performance of the lining, and provides technical support for the future toughness support design of soft rock tunnels. The specific advantages are as follows:

[0062] 1. The present invention's tunnel structural toughness assessment method, which considers the aging characteristics of soft rock, more comprehensively characterizes the stress state of the lining compared to existing performance assessment methods, effectively reflecting the unevenness of the lining stress. Ultimately, it generates a comprehensive indicator, or performance index, that reflects lining performance. The performance index ranges from 0 to 1, with 1 representing optimal performance and 0 representing the worst. The resulting performance index parameters are concise, facilitating better understanding and calculation of lining safety performance by designers and researchers.

[0063] 2. Compared to the existing safety factor method, the present invention's tunnel structural toughness assessment method, which considers the aging characteristics of soft rock, incorporates the temporal evolution of lining performance indicators, namely, a spatiotemporal evolution surface of lining performance indicators. This method effectively reflects the lining's response to long-term loads, enabling the calculation of the lining's toughness at different times, thereby assessing the lining's ability to resist external loads during tunnel operation.

[0064] 3. The present invention provides a tunnel structural toughness assessment method that considers the aging characteristics of soft rock. The proposed performance index calculation method can comprehensively reflect the impact of different lining performance parameters. The proposed performance parameter weight coefficient calculation method can automatically adjust the weight coefficients based on the safety of different control indicators. This calculation method not only ensures that the sum of all weight coefficients is 1, but also has the function of automatically assigning higher weight coefficients to control indicators that have a controlling effect on lining safety.

[0065] 4. Compared with the original toughness assessment method, the present invention's method for assessing tunnel structure toughness that takes into account the aging characteristics of soft rock not only considers the spatiotemporal evolution of lining performance indicators, but also the influence of the initial lining performance indicators. The calculated toughness index ranges from 0 to 1, where 1 represents the highest lining toughness and 0 represents the lowest lining toughness. The resulting toughness index is concise and easy to understand, and has a clear physical meaning.

[0066] In some possible implementations, in S1, the selected control indicators include lining concrete stress, steel bar stress, lining deformation and crack opening; the allowable values ​​of the control indicators include allowable values ​​of the control indicators inside the lining and allowable values ​​of the control indicators outside the lining.

[0067] Specifically, the control indicators include but are not limited to lining concrete stress, steel bar stress, lining deformation and crack opening; the allowable value of the control indicator is the maximum value of the control indicator, which can be directly obtained according to the existing specifications. The evaluation of lining toughness is divided into the evaluation of internal toughness of the lining and the evaluation of external toughness of the lining. The allowable value of the control indicator is divided into the allowable value of the control indicator inside the lining and the allowable value of the control indicator outside the lining.

[0068] In some possible implementations, the weight coefficient includes a lining internal weight coefficient αi内 and lining external weight coefficient α i外 , the weight coefficient α inside the lining i内 The calculation formula is as follows:

[0069]

[0070] Among them, θ 内 To characterize the internal position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is time; P i内 (θ 内 ,t) is the i-th control index inside the lining; α i内 is the weight coefficient of the i-th control index inside the lining; n is the total number of control indexes selected inside the lining;

[0071] The weight coefficient α of the external i外 The calculation formula is as follows:

[0072]

[0073] Among them, θ 外 To characterize the parameters of the external position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is the time; P i外 (θ 外 ,t) is the ith control index of the lining exterior; α i外 is the weight coefficient of the i-th control index of the lining exterior; n is the total number of control indexes selected for the lining exterior.

[0074] Specifically, The safety level of the internal control index of the lining, The safety degree of the internal control index of the lining is calculated by the safety degree of the control index to obtain the internal weight coefficient of the lining and the external weight coefficient of the lining. The calculation method of the internal weight coefficient of the lining and the external weight coefficient of the lining are the same, the difference is that θ 内 and θ 外 Different from the above, this calculation method can automatically adjust the weight coefficient according to the safety of different control indicators, which not only ensures that the sum of all weight coefficients is 1, but also has the function of automatically giving higher weight coefficients to control indicators that play a role in controlling lining safety; the lining internal weight coefficient and lining external weight coefficient are used for the subsequent calculation of lining internal performance indicators and lining external performance indicators respectively.

[0075] In some possible implementations, the performance index includes a lining internal performance index Q 内 (θ 内 ,t) and lining external performance index Q 外 (θ 外 ,t), the lining internal performance index Q 内 (θ内 ,t) is calculated as follows:

[0076]

[0077] Among them, Q 内 (θ 内 ,t) is the internal performance index of the lining; n is the total number of selected control indicators;

[0078] The lining external performance index Q 外 (θ 外 ,t) is calculated as follows:

[0079]

[0080] Among them, Q 外 (θ 外 , t) is the external performance index of the lining; n is the total number of selected control indicators.

[0081] Specifically, the range of the internal performance index and external performance index of the lining calculated by the present invention is 0 to 1, where 1 represents the best performance and 0 represents the worst performance. The obtained performance index parameters are concise, which facilitates designers and scientific researchers to better understand and calculate the safety performance of the lining.

[0082] In some possible implementations, in S1, the control index affecting the safety performance of the lining is selected based on site conditions and engineering experience; wherein, when the selected control index is stress, the P i内 (θ 内 ,t) represents the evolution of stress at different positions inside the lining over time. i外 (θ 外 ,t) represents the evolution of stress at different locations outside the lining over time; or, when the selected control index is deformation, the P i内 (θ 内 ,t) represents the evolution of deformation at different positions inside the lining over time. i外 (θ 外 ,t) represents the evolution law of deformation at different positions outside the lining with time.

[0083] Specifically, P i内 (θ 内 ,t) and P i外 (θ 外 ,t) can be adjusted according to the changes in the stress on the tunnel lining during the operation period.

[0084] In some possible implementations, the volume enclosed by the temporal and spatial evolution surface of the lining performance index considering the aging deformation of the surrounding rock, the time axis, and the space axis includes the volume V enclosed by the temporal and spatial evolution surface of the lining internal performance index, the time axis, and the space axis. 内(t1) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t1) The volume V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis is (t1) The calculation formula is as follows:

[0085]

[0086] Among them, V 内(t1) is the volume enclosed by the time axis and space axis of the surface of the temporal and spatial evolution of the lining internal performance index at time t1 when considering the time-dependent deformation of the surrounding rock; θ 内max is the maximum value of the internal parameters of the lining space, when θ 内 is the angle, then θ 内max is 360°;

[0087] The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis (t1) The calculation formula is as follows:

[0088]

[0089] Among them, V 外(t1) is the volume enclosed by the time axis and space axis of the spatiotemporal evolution surface of the lining external performance index at time t1 when considering the time-dependent deformation of the surrounding rock; θ 外max is the maximum value of the external parameters of the lining space, when θ 外 is the angle, then θ 外max It is 360°.

[0090] Specifically, considering the time-dependent deformation of the surrounding rock, a three-dimensional scatter plot is drawn based on the calculated performance indicators at different positions and times inside the lining. A three-dimensional surface fitting is performed to obtain the spatiotemporal evolution surface 5 of the lining internal performance indicators. From this, the volume V enclosed by the spatiotemporal evolution surface 5 of the lining internal performance indicators and the time axis and space axis can be obtained by calculation. 内(t1) , a three-dimensional scatter plot is drawn based on the calculated performance indicators of the lining at different positions and times, and a three-dimensional surface fitting is performed to obtain the spatiotemporal evolution surface 3 of the lining external performance indicators. Thus, the volume V enclosed by the spatiotemporal evolution surface 3 of the lining external performance indicators and the time axis and space axis can be obtained by calculation. 外(t1) ,θ 内 and θ 外 is the data of the spatial axis, t is the data of the time axis, where when θ 内 and θ 外When θ is the included angle, 内 and θ 外 Marking on lining see Figure 2 and Figure 3 , the inner radius of lining 1 is r1, and the outer radius of lining 1 is r2.

[0091] In some possible implementations, the volume enclosed by the temporal and spatial evolution surface of the lining performance index without considering the aging deformation of the surrounding rock, the time axis, and the space axis includes the volume V enclosed by the temporal and spatial evolution surface of the lining internal performance index, the time axis, and the space axis. 内(t0) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0) The area V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis is 内(t0) The calculation formula is as follows:

[0092]

[0093] Among them, V 内(t0) Q is the volume enclosed by the time-space evolution surface of the lining internal performance index when the time-dependent deformation of the surrounding rock is not considered, the time axis, and the space axis; 内 (θ 内 ,t0) is the performance index of the lining interior at the initial time t0;

[0094] The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0) The calculation formula is as follows:

[0095]

[0096] Among them, V 外(t0) Q is the volume enclosed by the time-space evolution surface of the lining external performance index when the time-dependent deformation of the surrounding rock is not considered, the time axis, and the space axis; 外 (θ 外 ,t0) is the performance index of the lining exterior at the initial moment t0.

[0097] Specifically, without considering the time-dependent deformation of the surrounding rock, the spatiotemporal evolution surface 4 of the internal performance index of the lining is parallel to the time axis plane, with an area of ​​1, and it forms a cube with the time axis and the space axis; correspondingly, the spatiotemporal evolution surface 3 of the external performance index of the lining is parallel to the time axis plane, with an area of ​​1, and it forms a cube with the time axis and the space axis.

[0098] In some possible implementations, the toughness index of the lining includes the toughness index Re of the interior of the lining. 内 (t) and the toughness index Re of the lining exterior 外 (t), the toughness index Re inside the lining内 The calculation formula of (t) is as follows:

[0099]

[0100] Among them, Re 内 (t) is the toughness index of the lining at time t;

[0101] The toughness index Re of the lining exterior 外 The calculation formula of (t) is as follows:

[0102]

[0103] Among them, Re 外 (t) is the toughness index of the lining exterior at time t;

[0104] The calculation formula for the overall toughness index of the internal and external lining is as follows:

[0105] Re(t)=Re 内 (t)×Re 外 (t);

[0106] Among them, Re(t) is the toughness index of the entire internal and external lining at time t.

[0107] Specifically, the toughness index of the lining outside and the toughness index of the lining inside are both in the range of 0 to 1, so that the overall toughness index of the inside and outside of the lining ranges from 0 to 1, where 1 represents the highest lining toughness and 0 represents the lowest lining toughness. The obtained toughness index is simple and easy to understand, and has a clear physical meaning.

[0108] In some possible implementations, in S3, a three-dimensional scatter plot is drawn based on the obtained performance index data of the lining at different positions and at different times, and a three-dimensional surface fitting is performed to reflect the response of the lining to long-term loads.

[0109] Specifically, the surface diagram finally obtained by plotting the performance index data of the lining at different positions and at different times is a surface diagram of the spatiotemporal evolution of the lining performance index taking into account the time-dependent deformation of the surrounding rock. It reflects the response of the lining to long-term loads and can more intuitively understand the safety performance of the lining at different positions and at different times.

[0110] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for evaluating the toughness of tunnel structures considering the aging characteristics of soft rock, characterized by: The tunnel structure toughness assessment method considering the aging characteristics of soft rock comprises the following steps: S1. Based on the actual conditions on site, select the control indicators that affect the safety performance of the lining and obtain the allowable values ​​of the selected control indicators; S2. Calculate the safety degree based on the obtained allowable values ​​of the control indicators, calculate the weight coefficients of different control indicators according to the weight ratio of the safety degree, and obtain the performance indicators of the lining at different positions and at different times according to the performance indicator calculation formula; S3. Draw a three-dimensional scatter plot based on the obtained performance index data of the lining at different positions and at different times, and perform three-dimensional surface fitting. According to the integral calculation of the three-dimensional surface, obtain the volume enclosed by the time axis and the space axis and the spatiotemporal evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock; S4. Calculate the volume enclosed by the time-space evolution surface of the lining performance index without considering the time-dependent deformation of the surrounding rock, the time axis, and the space axis. Compare the volume enclosed by the time-space evolution surface of the lining performance index with considering the time-dependent deformation of the surrounding rock, the time axis, and the space axis with the volume enclosed by the time-space evolution surface of the lining performance index without considering the time-dependent deformation of the surrounding rock, and obtain the toughness index of the lining at different times. S5. Based on the obtained toughness index of the lining at different times, the toughness index of the entire interior and exterior of the lining at different times is calculated using the calculation formula for the overall toughness index of the interior and exterior of the lining; In said S1, the selected control indicators include lining concrete stress, steel bar stress, lining deformation and crack opening; the control indicator allowable values ​​include the allowable values ​​of the control indicators inside the lining and the allowable values ​​of the control indicators outside the lining; The weight coefficient includes the lining internal weight coefficient α i内 and lining external weight coefficient α i外， The weight coefficient α inside the lining i内 The calculation formula is as follows: ； Among them, θ 内 To characterize the internal position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is time; P i内 (θ 内 ,t) is the i-th control index inside the lining; α i内 is the weight coefficient of the i-th control index inside the lining; n is the total number of control indexes selected inside the lining; The weight coefficient α of the external i外 The calculation formula is as follows: ； Among them, θ 外 To characterize the parameters of the external position of the lining space, the angle between the coordinate point and the coordinate axis can be taken; t is the time; P i外 (θ 外 ,t) is the ith control index of the lining exterior; α i外 is the weight coefficient of the ith control index of the lining exterior; n is the total number of selected control indexes of the lining exterior; The performance index includes the lining internal performance index Q 内 (θ 内 ,t) and lining external performance index Q 外 (θ 外 ,t), the lining internal performance index Q 内 (θ 内 ,t) is calculated as follows: ； Among them, Q 内 (θ 内 ,t) is the internal performance index of the lining; n is the total number of selected control indicators; The lining external performance index Q 外 (θ 外 ,t) is calculated as follows: ； Among them, Q 外 (θ 外 , t) is the external performance index of the lining; n is the total number of selected control indicators.

2. The method for evaluating tunnel structure toughness considering the aging characteristics of soft rock according to claim 1, characterized in that: In S1, the control index affecting the safety performance of the lining is selected based on the site conditions and engineering experience; wherein, when the selected control index is stress, the P i内 (θ 内 ,t) represents the evolution of stress at different positions inside the lining over time. i外(θ外 ,t) represents the evolution of stress at different locations outside the lining over time; or, when the selected control index is deformation, the P i内 (θ 内,t ) represents the evolution of deformation at different positions inside the lining over time. i外 (θ 外 ,t) represents the evolution law of deformation at different positions outside the lining with time.

3. The method for evaluating tunnel structure toughness considering the aging characteristics of soft rock according to claim 2, characterized in that: The volume enclosed by the temporal and spatial evolution surface of the lining performance index considering the time-dependent deformation of the surrounding rock, the time axis and the space axis includes the volume V enclosed by the temporal and spatial evolution surface of the lining internal performance index, the time axis and the space axis. 内(t1) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t1) The volume V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis is (t1) The calculation formula is as follows: ； Among them, V 内(t1) is the volume enclosed by the time axis and space axis of the surface of the temporal and spatial evolution of the internal performance index of the lining at time t1 when considering the time-dependent deformation of the surrounding rock; θ 内max is the maximum value of the internal parameters of the lining space, when θ 内 is the angle, then θ 内max is 360°; The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis (t1) The calculation formula is as follows: ； Among them, V 外(t1) is the volume enclosed by the time axis and space axis of the spatiotemporal evolution surface of the lining external performance index at time t1 when considering the time-dependent deformation of the surrounding rock; θ 外max is the maximum value of the external parameter of the lining space, when θ 外 is the angle, then θ 外max It is 360°.

4. The method for evaluating the toughness of a tunnel structure considering the aging characteristics of soft rock according to claim 3, characterized in that: The volume enclosed by the time-space evolution surface of the lining performance index without considering the aging deformation of the surrounding rock, the time axis and the space axis includes the volume V enclosed by the time-space evolution surface of the lining internal performance index, the time axis and the space axis. 内(t0) , and the volume V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0)， The area V enclosed by the spatiotemporal evolution surface of the lining internal performance index and the time axis and space axis 内(t0) The calculation formula is as follows: ； Among them, V 内(t0) Q is the volume enclosed by the time-space evolution surface of the lining internal performance index when the time-dependent deformation of the surrounding rock is not considered, the time axis, and the space axis; 内 (θ 内 ,t0) is the performance index of the lining interior at the initial time t0; The area V enclosed by the spatiotemporal evolution surface of the lining external performance index and the time axis and space axis 外(t0) The calculation formula is as follows: ； Among them, V 外(t0) Q is the volume enclosed by the time-space evolution surface of the lining external performance index when the time-dependent deformation of the surrounding rock is not considered, the time axis, and the space axis; 外 (θ 外 ,t0) is the performance index of the lining exterior at the initial moment t0.

5. The method for evaluating the toughness of a tunnel structure considering the aging characteristics of soft rock according to claim 4, characterized in that: The toughness index of the lining includes the toughness index Re inside the lining 内 (t) and the toughness index Re of the lining exterior 外 (t), the toughness index Re inside the lining 内 The calculation formula of (t) is as follows: ； Among them, Re 内 (t) is the toughness index of the lining at time t; The toughness index Re of the lining exterior 外 The calculation formula of (t) is as follows: ； Among them, Re 外 (t) is the toughness index of the lining exterior at time t.

6. The method for evaluating the toughness of a tunnel structure considering the aging characteristics of soft rock according to claim 5, characterized in that: The calculation formula for the overall toughness index of the internal and external lining is as follows: ； Among them, Re(t) is the toughness index of the entire internal and external lining at time t.

7. The method for evaluating tunnel structure toughness considering the aging characteristics of soft rock according to claim 6, characterized in that: In S3, a three-dimensional scatter plot is drawn based on the obtained performance index data of the lining at different positions and at different times, and a three-dimensional surface fitting is performed to reflect the response of the lining to the long-term load.

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