PCC pile-based signal error analysis method for high-speed rail seismic survey well structure

Abstract

The invention discloses a signal error analysis method for a high-speed rail seismic survey well structure based on PCC piles. The signal error analysis method comprises the steps that an arrangement area is selected, wherein a proper area is selected to preset a seismic survey well; the diameter and depth of the PCC pile are designed, and a mechanical model is established; acquiring soil body information from an exploration report of the arrangement area; a frame of the seismic well is manufactured through a PCC pile using method; debugging the sensitivity of the sensor; the arrangement of the seismic well is completed; establishing a control equation based on a Hamiltonian minimum capability principle, and substituting the control equation into boundary conditions for solving; calculating a signal error; according to the method, the error can be analyzed and evaluated quickly and efficiently.

Description

Technical Field

[0001] The present invention relates to the technical field of railway disaster prevention and mitigation, and in particular to a signal error analysis method for a high-speed railway seismic survey well structure based on PCC piles. Background Art

[0002] Earthquakes are one of the most harmful natural disasters to railway transportation. When an earthquake occurs, running trains and high-speed trains may derail or be affected by unstable surrounding mountain rockfalls, seriously endangering the lives of train passengers and drivers. Moreover, China is located between the Circum-Pacific Seismic Belt and the Eurasian Seismic Belt, and most railway lines pass through earthquake-prone areas. When an earthquake occurs along a railway line, the economic and social impacts are immeasurable. Therefore, when an earthquake occurs along a railway line, by using earthquake monitoring technologies such as survey wells to quickly obtain earthquake signals and conduct rapid earthquake warnings, the losses caused by earthquakes can be effectively reduced.

[0003] In earthquake monitoring work, it is particularly important to be able to give accurate warnings of the coming of an earthquake.

[0006] At present, China's earthquake warning technology mainly relies on manual warnings. There are safety hazards when staff conduct manual warnings when an earthquake comes, so it is necessary to transition to technical earthquake warnings. However, China is not yet developed in technical earthquake warnings, and there are errors in the warning results. Usually, the detected earthquake signals are regarded as surface signals, but in fact, due to the soil-structure interaction between the survey well and the soil mass, there will be signal disturbances between the two, resulting in distortion of the monitored signals. Summary of the Invention

[0007] To solve the problems existing in the prior art, the purpose of the present invention is to provide a signal error analysis method for a high-speed railway seismic survey well structure based on PCC piles, which can quickly and efficiently analyze and evaluate errors.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is: a signal error analysis method for a high-speed railway seismic survey well structure based on PCC piles, comprising the following steps:

[0009] Step 1, select the layout area: select a suitable area to preset the survey well;

[0010] Step 2, design the diameter and depth of the PCC pile and establish a mechanical model;

[0011] Step 3, obtain soil information from the exploration report of the layout area;

[0012] Step 4, make the frame of the survey well by using the PCC pile method;

[0013] Step 5: Conduct sensitivity debugging of the sensor;

[0014] Step 6: Complete the layout of the seismic monitoring well;

[0015] Step 7: Establish the control equation based on the Hamilton's principle of minimum energy and substitute the boundary conditions for solution;

[0016] Step 8: Calculate the signal error.

[0017] As a further improvement of the present invention, step 2 is specifically as follows:

[0018] Set the depth of the PCC pile as H, the outer diameter as d, and the inner radius as r a , the outer radius as R, and the distance from the top of the soil mass to the top of the bedrock as D; where 2H = D, d = 2R, and H / d < 10.

[0019] As a further improvement of the present invention, in step 3, the soil mass information includes: Young's modulus E of the soil mass s , Poisson's ratio v s , hysteretic damping ratio β0, complex modulus E s * , soil density ρ s , Young's modulus E of the seismic monitoring well w , Poisson's ratio v w , density ρ w , complex shear modulus G s * ; where: complex modulus E s * = E s (1 + 2iβ0), complex shear modulus G s * = E s * / [2(1 + v s )]

[0020] As a further improvement of the present invention, step 7 is specifically as follows:

[0021] Harvest the harmonic ω, substitute it into the control equation, and solve for the displacement W of the empty column, the displacement W of the foundation part of the seismic monitoring well hollow , and the displacement W of the virtual soil column foundatioon , and calculate the displacement W of the top of the foundation part of the seismic monitoring well soil (L) and the displacement W of the bottom of the foundation part of the seismic monitoring well foundation (H) by subtracting the lower value from the upper value. foundation

[0022] As a further improvement of the present invention, the solution method is specifically as follows:

[0023] Denote "hollow", "foundation", and "soil" as h, f, and s respectively; A represents the area of a certain region.

[0024] A h = π(R 2 - r a 2 )², A f = πR² 2 ;

[0025]

[0026] w f (z) = w g + W f (z)

[0027] where w f (z) is the displacement of the free field in the vertical direction; w g is the amplitude of the incident wave; W f (z) is the relative displacement of the free field with respect to the bedrock; k, 2c, and 2b represent the influence of the soil around the well and are parameters; λ 2 can be regarded as a parameter

[0028]

[0029] W hollow :

[0030]

[0031] Under the boundary conditions:

[0032]

[0033]

[0034] W foundation :

[0035]

[0036] Under the boundary conditions:

[0037] w holow = w foumdaion (z = L)

[0038]

[0039] W soil :

[0040]

[0041] Under the boundary conditions:

[0042] w foundation = w soil (z = H)

[0043] w soil = w g (z = D)

[0044] According to Hamilton's principle, the coefficients collected by δφ are used to obtain the control equation φ(r) of the attenuation function as follows:

[0045] Where:

[0046]

[0047] Under the boundary conditions:

[0048]

[0049] The solution is:

[0050]

[0051] Where K0(.) is the modified Bessel function of the second kind of order zero; W hollow The solution of is:

[0052]

[0053] Where:

[0054]

[0055] According to the boundary conditions, the equations for c5 and c6 are:

[0056] c5 = c6

[0057]

[0058] W foundation The solution of is:

[0059]

[0060] Where:

[0061]

[0062] According to the boundary conditions, the equations for c1, c2, c3, c4, c5 are:

[0063] W soil The solution of is:

[0064]

[0065] Among them:

[0066] ξ s = ξ s / (λ 2 + α s 2 )

[0067] According to the boundary conditions, the equations for c1, c2, c3, and c4 are

[0068]

[0069] The solutions for c1, c2, c3, c4, c5, and c6 are:

[0070]

[0071] c6 = c5

[0072]

[0073] Among them, χ 1，2 , K 1,2 , α, and ζ are coefficients.

[0074] As a further improvement of the present invention, in step 8, the calculation method of the signal error is specifically as follows:

[0075] According to the displacement W foundation (L) at the top of the foundation part of the seismograph well and the displacement W foundation (H) at the bottom of the foundation part of the seismograph well, the relative monitoring error E r is solved:

[0076]

[0077] As a further improvement of the present invention, in step 4, the side wall of the seismograph well is made using the PCC pile method, and then grouting is carried out at the bottom to set it as the foundation part of the well; the distance L from the foundation part of the seismograph well to the top of the well is measured, and the height M of the foundation part of the well is calculated therefrom: M = H - L.

[0078] The beneficial effects of the present invention are:

[0079] 1. So far, the PCC pile has not been used in the construction technology of earthquake early warning. Using the PCC pile technology to set up the seismograph well and constructing the well wall of the seismograph well by perfusion can make the soil body and the well wall of the seismograph well adhere tightly together, thereby reducing the error caused by the inappropriate establishment of the coupling body between the seismograph well and the surrounding soil due to the loose contact between the seismograph well and the surrounding soil.

[0080] 2. By using PCC piles to manufacture the wellbore of the seismic monitoring well, the wellbore has a greater bearing capacity. When an earthquake occurs, the wellbore of the seismic monitoring well fabricated by the PCC pile process is not prone to structural changes and can well maintain the stability of the seismic monitoring well structure.

[0081] 3. The seismic monitoring well fabricated by the PCC pile process is buried underground. By setting the seismic monitoring well underground, the error caused by seismic force can be effectively reduced, and the electromagnetic interference from the ground surface can be effectively blocked.

[0082] 4. The PCC pile process has a complete construction system. The construction process of the PCC pile process is simple, low-carbon and environmentally friendly, meeting the dual-carbon policy.

[0083] 5. The seismic monitoring well fabricated by the PCC pile process has a smaller length-diameter ratio. A smaller length-diameter ratio can increase the dynamic response coefficient and reduce errors. And when the seismic monitoring well fails, a larger pile diameter allows workers to enter the well for repair, greatly extending the service life of the seismic monitoring well.

[0084] 6. A theoretical signal error analysis method has not been theoretically proposed. The existing signal error analysis methods mainly rely on the finite element method for analysis. By using the finite element analysis, the calculation amount is large, the speed is slow, and there are errors in the analysis process, which is not conducive to rapid evaluation. By using the method in the present invention for error analysis, rapid and efficient evaluation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is the overall flowchart of the embodiment of the present invention;

[0086] Figure 2 is the flowchart for solving W foundation 、W hollow 、W soil in the embodiment of the present invention;

[0087] Figure 3 is the schematic diagram of the influence of the length-diameter ratio on the dynamic response coefficient in the embodiment of the present invention;

[0088] Figure 4 is the schematic diagram of the coupling body of the seismic monitoring well and the soil body in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0089] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0090] Embodiment

[0091] As Figure 1 shown, a high-speed rail earthquake monitoring and signal error analysis method based on PCC piles includes the following steps:

[0092] (1) Select the installation location: Select a suitable area to preset the seismic monitoring well.

[0093] (2) Design the diameter and depth of the PCC pile and establish a mechanical model: Set the depth H, outer diameter d, and inner radius r of the PCC pile a , outer radius R, diameter d = 2R, and satisfy H / d < 10.

[0094] (3) Obtain soil information from the exploration report of the installation area: Measure and obtain the Young's modulus E of the soil around the seismic monitoring well at the selected installation location s , Poisson's ratio v s , hysteretic damping ratio β0, complex modulus E s * , soil density ρ s , Young's modulus E of the seismic monitoring well w , Poisson's ratio v w , density ρ w , complex shear modulus G s * . Complex modulus E s * = E s (1 + 2iβ0), complex shear modulus G s * = E s * / [2(1 + v s )].

[0095] (4) Fabricate the frame of the seismic monitoring well by using the PCC pile method: Fabricate the side well wall of the seismic monitoring well by using the PCC pile method, and then perform grouting at the bottom to set it as the foundation part of the well. The distance from the foundation part of the seismic monitoring well to the top of the well is L, and the height M of the foundation part of the well is deduced therefrom.

[0096] Where M = H - L.

[0097] (5) Conduct sensor sensitivity debugging: Conduct sensor sensitivity debugging on the accelerator sensor and displacement sensor respectively. If the sensor sensitivity is not good, reset the sensor.

[0098] (6) Complete the layout of the seismic monitoring well.

[0099] (7) Establish the control equation based on Hamilton's principle of minimum energy and substitute the boundary conditions to solve: Obtain the harmonic ω, substitute it into the control equation, and solve for W hollow (empty column displacement), W foundatioon (displacement of the foundation part of the seismic monitoring well), W soil (virtual soil column displacement), and calculate W foundation (L) (displacement of the top of the foundation part of the seismic monitoring well) by subtracting the lower value from the upper value,foundation (H) (Displacement at the bottom of the foundation part of the seismograph well).

[0100] (8) Calculate the signal error: According to W foundation (L) (Displacement at the top of the foundation part of the seismograph well) and W foundation (H) (Displacement at the bottom of the foundation part of the seismograph well), solve for the relative monitoring error E r .

[0101] In step (2), H and D satisfy: 2H = D; where H is the depth of the PCC pile and D is the distance from the top of the soil to the top of the bedrock; the relationship between the complex modulus of the soil, the Young's modulus of the soil, and the hysteretic damping ratio of the soil satisfies:

[0102] The complex modulus of the soil E s * = E s (1 + 2iβ0);

[0103] The relationship between the complex shear modulus of the soil, the complex modulus of the soil, and the Poisson's ratio of the soil satisfies:

[0104] The complex shear modulus of the soil G s * = E s * / [2(1 + v s )];

[0105] Where E s * is the complex modulus of the soil, E s is the Young's modulus of the soil, β0 is the hysteretic damping ratio of the soil, G s * is the complex shear modulus of the soil, v s is the Poisson's ratio of the soil.

[0106] As Figure 2 shown, the solutions for W hollow (hollow column displacement), W foundatioon (displacement of the foundation part of the seismograph well), and W soil (displacement of the virtual soil column) are:

[0107] Among them, English words such as hollow, foundation, and soil can be abbreviated as h, f, s;

[0108] A represents the area of a certain region;

[0109] A h = π(R 2 - r a 2 ), A f = πR 2 ;

[0110]

[0111]

[0112] wf(z) = wgg + Wf(z)

[0113] where wf(z) is the displacement of the free field in the vertical direction; wg is the amplitude of the incident wave; Wf(z) is the relative displacement of the free field with respect to the bedrock; k, 2c, 2b represent the influence of the soil around the well and are parameters; λ2 can be regarded as a parameter.

[0114]

[0115] W hollow :

[0116]

[0117] Under the boundary conditions:

[0118]

[0119] W foundation :

[0120]

[0121] Under the boundary conditions:

[0122] wholow = wfoumdaion(z = L)

[0123]

[0124] W soil :

[0125]

[0126] Under the boundary conditions:

[0127] w foundation = w soil (z = H)

[0128] w soil = w g (z = D)

[0129] According to Hamilton's principle, collecting the coefficients of δφ, the control equation φ(r) of the attenuation function is obtained as follows:

[0130] where

[0131]

[0132] Under boundary conditions:

[0133]

[0134] Its solution is:

[0135]

[0136] where \(K_0(.)\) is the modified zero-order Bessel function of the second kind.

[0137] W hollow The solution of is:

[0138]

[0139] where

[0140]

[0141] According to the boundary conditions, the equations for \(c_5\) and \(c_6\) are:

[0142] \(c_5 = c_6\)

[0143]

[0144] W foundation The solution of is:

[0145]

[0146] where

[0147]

[0148] According to the boundary conditions, the equations for \(c_1\), \(c_2\), \(c_3\), \(c_4\), \(c_5\) are:

[0149] W soil The solution of is:

[0150]

[0151] where \(\xi_s=\xi_s / (\lambda^2 + \alpha^2)\)

[0152] According to the boundary conditions, the equations for \(c_1\), \(c_2\), \(c_3\), \(c_4\) are

[0153] The solutions for \(c_1\), \(c_2\), \(c_3\), \(c_4\), \(c_5\), \(c_6\) are:

[0154]

[0155]

[0156] c6 = c5

[0157]

[0158] where χ1, 2, K 1,2 , α, ζ are coefficients.

[0159] E r is expressed as:

[0160] As Figure 3 shown, the seismometer well manufactured by the PCC pile process has a smaller length-diameter ratio. A smaller length-diameter ratio can increase the dynamic response coefficient and reduce errors. Moreover, when the seismometer well fails, a larger pile diameter allows workers to enter the seismometer well for repair, greatly increasing the service life of the seismometer well.

[0161] When using the PCC pile technology to set up the seismometer well, the well wall of the seismometer well is constructed by pouring, so that the soil body and the well wall of the seismometer well can be tightly adhered together, thereby reducing the error caused by the improper establishment of the coupling body between the seismometer well and the surrounding soil due to the loose contact between the seismometer well and the surrounding soil, as Figure 4 shown.

[0162] The above-described embodiments merely represent the specific implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for signal error analysis of a high-speed railway seismic survey well structure based on PCC piles, characterized in that, It includes the following steps: Step 1. Select the layout area: Select a suitable area to preset the seismic monitoring well; Step 2. Design the diameter and depth of the PCC pile and establish a mechanical model; Step 3. Obtain soil information from the exploration report of the layout area; Step 4. Complete the layout of the seismic monitoring well; Step 5. Use the PCC pile method to fabricate the frame of the seismic monitoring well; Step 6. Conduct sensor sensitivity debugging; Step 7. Establish the control equation based on Hamilton's principle of minimum energy and substitute the boundary conditions for solution; Step 8. Calculate the signal error.

2. The signal error analysis method for the high-speed rail seismic survey well structure based on PCC piles according to claim 1, characterized in that The specific content of Step 2 is as follows: Set the depth of the PCC pile to be H, the outer diameter to be d, and the inner radius to be r a , the outer radius to be R, and the distance from the top of the soil mass to the top of the bedrock to be D; where 2H = D, d = 2R, and H / d < 10 is satisfied.

3. The signal error analysis method for the high-speed railway seismic survey well structure based on PCC piles according to claim 1, characterized in that, In step 3, the soil body information includes: Young's modulus E of the soil body s , Poisson's ratio v s , hysteretic damping ratio β0, complex modulus E s * , soil density ρ s , Young's modulus E of the seismic observation well w , Poisson's ratio v w , density ρ w , complex shear modulus G s * ; where: complex modulus E s * = E s (1 + 2iβ0), complex shear modulus G s * = E s * / [2(1 + v s )].

4. The signal error analysis method for the high-speed railway seismic survey well structure based on PCC piles according to claim 3, characterized in that The specific content of Step 7 is as follows: Harvest the harmonic wave ω, substitute it into the control equation, and solve for the displacement W of the empty column under the boundary conditions hollow and the displacement W of the foundation part of the seismograph well foundatioon and the displacement W of the virtual soil column soil , and use the method of subtracting the lower from the upper to find the displacement W foundation (L) of the top of the foundation part of the seismograph well and the displacement W foundation (H) of the bottom of the foundation part of the seismograph well.

5. The signal error analysis method for the high-speed railway seismic survey well structure based on PCC piles according to claim 4, characterized in that, The specific solution method is as follows: Denote hollow, foundation, and soil as h, f, and s; A represents the area of a certain region; A h = π(R 2 - r a 2 ), A f = πR 2 ; w f f(z) = w g + W f f(z) where, w f (z) is the displacement of the free field in the vertical direction; w g is the amplitude of the incident wave; W f (z) is the relative displacement of the free field with respect to the bedrock; k, 2c, 2b represent the influence of the soil around the well and are parameters; λ 2 can be regarded as a parameter; W hollow : Under the boundary conditions: W foundation ： Under the boundary conditions: w holow = w foumdaion (z = L) W soil ： Under the boundary conditions: w foundation = w soil (z = H) w soil = w g (z = D) According to Hamilton's principle, δ φ Collecting the coefficients, the governing equation of the attenuation function φ(r) is obtained as follows: Where: Under the boundary conditions: The solution is: where, K0(.) is the modified Bessel function of the second kind of order zero; W hollow The solution of is: Where: According to the boundary conditions, the equations for c5 and c6 are: c5 = c6 W foundation The solution of Where: According to the boundary conditions, the equations for c1, c2, c3, c4, and c5 are: W soil The solution for: Where: ξ s = ξ s / (λ 2 + α s 2 ) According to the boundary conditions, the equations for c1, c2, c3, and c4 are as follows The solutions for c1, c2, c3, c4, c5, and c6 are: c6 = c5 Among them, χ 1，2 , K 1,2 , α, and ζ are coefficients.

6. The signal error analysis method for the high-speed railway seismic survey well structure based on PCC piles according to claim 5, characterized in that, In Step 7, the specific method for calculating the signal error is as follows: Based on the displacement W foundation (L) at the top of the foundation part of the seismograph well and the displacement W foundation (H) at the bottom of the foundation part of the seismograph well, the relative monitoring error E is solved r :

7. The signal error analysis method for the high-speed rail seismic survey well structure based on PCC piles according to claim 6, characterized in that In Step 4, use the PCC pile method to fabricate the side wall of the seismic monitoring well, and then conduct grouting at the bottom to set it as the foundation part of the well; the distance from the foundation part of the seismic monitoring well to the top of the well is L, and based on this, the height M of the foundation part of the well is deduced: M = H - L.

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