CN114839678A - Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test - Google Patents

Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test Download PDF

Info

Publication number
CN114839678A
CN114839678A CN202210477037.8A CN202210477037A CN114839678A CN 114839678 A CN114839678 A CN 114839678A CN 202210477037 A CN202210477037 A CN 202210477037A CN 114839678 A CN114839678 A CN 114839678A
Authority
CN
China
Prior art keywords
soil
depth
boundary
soil layer
seismic wave
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210477037.8A
Other languages
Chinese (zh)
Inventor
王浩
杨庆
孔纲强
裴华富
唐冲
张橦
于明昊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dalian University of Technology
Original Assignee
Dalian University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dalian University of Technology filed Critical Dalian University of Technology
Priority to CN202210477037.8A priority Critical patent/CN114839678A/en
Publication of CN114839678A publication Critical patent/CN114839678A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/28—Processing seismic data, e.g. analysis, for interpretation, for correction
    • G01V1/30—Analysis
    • G01V1/303—Analysis for determining velocity profiles or travel times
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D1/00—Investigation of foundation soil in situ
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/30—Assessment of water resources

Abstract

A complex soil layer shear wave velocity calculation method based on a seismic wave static cone penetration test comprises the following steps: acquiring data of the distribution of the corrected cone tip resistance and the side friction resistance along the depth in the seismic wave static cone penetration test, and solving the distribution value of the soil property type index along the depth; calculating the parameter value of each parameter along a certain depth and correcting the parameter value to be the average value of the parameter values at a plurality of adjacent depths to obtain a smooth distribution curve of the parameter along the depth; soil layer division is carried out by comprehensively applying the soil property type index and correcting the cone tip resistance, and soil layer boundary lines are divided into four categories by applying condition judgment; combining and removing boundary lines of four types of soil layers according to a specific test method and a following standard, and adding an auxiliary boundary line to finish soil layer division for shear wave velocity calculation; and (3) applying the Snell's law, the actually measured seismic wave transmission duration and new soil body layering, and applying a forward simulation method to iteratively solve the shear wave velocity of each soil layer to obtain a distribution curve of the shear wave velocity of the soil body along the depth.

Description

Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test
Technical Field
The invention belongs to the technical field of data analysis of in-situ tests in geotechnical engineering subjects, and particularly relates to a method for calculating soil shear wave velocity based on measured data of a seismic static sounding test and suitable for complex engineering geological conditions.
Background
The seismic wave static sounding test is an advanced geotechnical engineering in-situ testing technology, and has been widely applied to the large-scale engineering construction of airports, bridges, expressways, super high-rise buildings and the like all over the world since the invention in the 80's 20 th century. The main actual measurement data of the traditional static cone penetration test are cone tip resistance, side friction resistance and dynamic pore water pressure, and the method is mainly used for obtaining the strength parameters of the soil body. On the basis of the static sounding test, the seismic wave static sounding test increases the measurement of the shear wave velocity of the soil body by collecting the seismic wave propagation information, can obtain the in-situ shear stiffness of the soil body, and provides an important basis for the deformation and settlement calculation of the building foundation.
In recent years, scholars at home and abroad optimize a test method of seismic wave static sounding, but certain defects still exist in the aspect of analysis technology of seismic wave actual measurement data, and related researches are relatively few. The existing data analysis techniques include interval analysis based on mechanical wave straight-line path propagation assumptions as proposed by Campanella and Robertson (Campanella, R.G., Robertson, P.K.,1984.A semi-conductor penetrometer to measurement engineering properties of soil. in: SEG Technical Program Expanded abstract 1984.Society of expansion geophysics, pp.138-141.) and interval analysis based on Baziw (Baziw, E.J.,2002. differentiation of semi-conductor interval diffraction modeling and the downed 118simplex method. Can. C.Refraction. J.39(5), 1. 1192) as proposed by the law of mechanical wave straight-line path propagation. Both methods have an inherent limitation in that the division of the earth layers to calculate shear wave velocity must be consistent with the interval of seismic acquisition. For example, in practical experiments, seismic waves are generally triggered once every one-meter depth, and the shear wave velocity obtained by the two analysis methods is an average value of soil bodies with one-meter thickness in intervals. In fact, for engineering geological conditions with complex soil layer distribution, the average value of the soil shear wave speed in a fixed interval is often not enough to reflect the essential properties of soil materials. For example, the boundary of two soil layers with great rigidity difference is probably not at the acquisition depth of seismic waves, but in the interval, or a weak soil layer may exist in the interval, and the rigidity boundaries cannot be displayed through the calculation result of the fixed interval, so that the shear rigidity of a part of soil body in the interval may be overestimated or underestimated, and a significant risk is brought to the later engineering safety design.
Therefore, based on the measured data of the seismic wave static sounding test, the measured correction cone tip resistance and the soil property type index are used for dividing the soil body in a layered mode, then the snell's law and the measured seismic wave transmission duration are applied to carry out refraction path analysis on new soil body layers, and the intrinsic shear wave velocity of each soil layer is obtained, so that the calculation accuracy of the seismic wave static sounding test on the shear stiffness of complex soil layers is improved, and the safety and the reliability of settlement design of a building foundation according to the standard are guaranteed.
Disclosure of Invention
The invention aims to utilize the measured data of a seismic wave static sounding test, carry out layered division on a soil body by correcting cone tip resistance and a soil property type index, and carry out refraction path analysis on a new soil body layer by applying a snell's law and the measured seismic wave transmission duration, thereby providing a complex soil layer shear wave velocity calculation method based on the seismic wave static sounding test. The technical scheme is as follows: firstly, acquiring distribution data of corrected cone tip resistance and side friction resistance along the depth in a group of seismic wave static cone penetration tests, and solving a distribution value of a soil property type index along the depth; secondly, calculating the moving average value of each parameter along the depth, namely correcting the parameter value at a certain depth into the average value of the parameter values at a plurality of adjacent depths to obtain a smooth distribution curve of the parameter along the depth; then, soil layer division is carried out by comprehensively applying the soil property type index and the corrected conical tip resistance, and soil layer boundary lines are divided into four categories by applying condition judgment; secondly, combining and removing boundary lines of the four types of soil layers according to a specific test method and a following standard, and adding an auxiliary boundary line to finish the soil layer division for shear wave velocity calculation; and finally, applying Snell's law, the actually measured seismic wave transmission duration and new soil body layering, and applying a forward modeling method to iteratively solve the shear wave velocity of each soil layer to obtain a distribution curve of the shear wave velocity of the soil body along the depth.
A complex soil layer shear wave velocity calculation method based on a seismic wave static cone penetration test comprises the following steps:
the method comprises the following steps: initial parameter acquisition and calculation
(1) Obtaining corrected cone tip resistance q in single group of measured data t And side friction resistance f s Distributing data along the depth, assigning an SBT value to the data at each depth according to a static penetration soil classification map (SBT map) provided by Robertson, and then calculating the volume weight of the soil at each depth by applying a classical fitting relation table provided by Lunne and the like:
Figure BDA0003626241600000021
(2) calculating the vertical total stress sigma according to the volume weight of the soil body, the water level line and the additional load of the field v0 And vertical effective stress σ v0 Distribution along depth, and calculation of soil property type index I according to the following formula c And (3) distribution along the depth:
I c ＝[(3.47-logQ t ) 2 +(logF r +1.22) 2 ] 0.5 ,
Figure BDA0003626241600000031
step two: calculating a moving average of each parameter
(3) In order to reduce the influence of local data errors caused by factors such as drilling and standing on an analysis result, the moving average value of each parameter is solved:
Figure BDA0003626241600000032
in the formula, P k Represents the kth reading of a certain parameter P and m represents the number of readings contained forward and backward in the solution of the moving average. Most of the currently electronically controlled hydrostatic sounding equipment is capable of achieving one reading per centimeter of depth, in which case m may typically be taken to be 9.
Step three: identification of boundary of four major soil layers
(4) Soil property type index I proposed by Robertson c Is the basis for dividing the soil property which is widely accepted by the industry. According to I c And layering the soil body along the distribution curve of the depth to determine the depth of the boundary of the soil layer. I at the boundary c The characteristic values were 1.31, 2.05, 2.60, 2.95 and 3.6. The top layer of 1 meter and the deepest 0.5 meter did not participate in delamination. Five times the bit diameter is defined as the thickness of the thin layer. If the distance between the boundary lines of two adjacent soil layers is less than the thickness of the thin layer, and I c If the characteristic values are the same, the boundary lines at the two parts need to be removed; if the distance between two or more adjacent soil layer boundary lines is less than the thickness of the thin layer and has increasing or decreasing I c The feature values are merged into one place at the average depth of the boundaries.
(5) Following the research thought of Boulanger and Dejong, it is believed that when q is t The rate of change along the depth being above a certain value means a change in the nature of the soil mass, passing through q t The rate of change of value along the depth is divided into soil layers. Definition of q t Rate of change along the depth of D qt The expression is as follows:
Figure BDA0003626241600000033
wherein (q) t ) i And D i Representing the ith reading of corrected cone tip resistance and depth, respectively. Will D qt Is set to 5, i.e. when adjacent q t And when the difference of the readings is more than 5%, the soil property is considered to be changed in a transition way. Get D qt D > 5 qt And the extreme value is used as a soil boundary. The top layer of 1 meter and the deepest 0.5 meter did not participate in delamination. If the distance between the boundary lines of two adjacent soil layers is smaller than the thickness of the thin layer, the two soil layers are combined into one position, and the position is at the average depth of the two soil layers.
(6) And classifying the soil layer boundary obtained in the two steps. First, when applying I c Demarcating and applying q t When the distance between the boundaries of the division is smaller than the thickness of the thin layer, the two are merged to define a new boundary as a significant boundary, which is located at the average depth of the two. And secondly, when the depth of a certain boundary line is smaller than the acquisition depth of the seismic waves than the thickness of the thin layer, moving the boundary line to the acquisition depth of the seismic waves, and defining the boundary line as a test boundary line. This step is to ensure the convergence of the subsequent shear wave velocity value iterative computation. Finally, defining soil layer boundary lines which do not conform to the two soil layer boundaries as I according to the division form c Boundary line and q t A dividing line.
Step four: final division of soil horizon boundary
(7) The seismic wave acquisition depth interval recommended by the existing specifications is between 0.5 and 1.5 meters. At present, most of projects at home and abroad adopt a form of seismic wave acquisition per whole meter. In order to ensure the uniqueness of the shear wave velocity numerical solution distributed along the depth, the number of newly divided soil layers needs to be equal to the number of seismic wave acquisition tests, so that the final soil body layering thickness is not suitable to be less than 0.5 m. Based on this, the four major soil layer boundaries obtained in the previous step need to be divided as follows: when adjacent to I c Boundary or significant boundary spacing of less than 0.5 m and I c When the values are the same, both need to be removed; when adjacent to I c Boundary or significant boundary spacing of less than 0.5 m and I c When the values are different, the two are merged at the average depth; when more than three adjacent places I c Demarcation line orThe distances between the remarkable boundary lines are less than 0.5 m, only the top and bottom boundary lines are reserved, and the inner boundary line is removed; removing I within 0.5 m of the significant or experimental boundary c Boundary line and q t A boundary line; removing a significant boundary within 0.5 meters of the test boundary.
(8) When no soil layer boundary exists within 0.5 m of the seismic wave acquisition depth, an auxiliary boundary is added at the depth, so that the number of newly divided soil layers is equal to the number of seismic wave acquisition tests. Therefore, soil body layering according to the soil body properties is completed, and a foundation is laid for accurate shear wave velocity solving.
Step five: numerical iterative solution of shear wave velocity
(9) The shear wave velocity is solved by applying the Snell's law, the actually measured seismic wave transmission time and the new soil body layer, and the specific formula is as follows:
Figure BDA0003626241600000041
Figure BDA0003626241600000042
Figure BDA0003626241600000043
in the formula (I), the compound is shown in the specification,
Figure BDA0003626241600000044
the refraction angle of the seismic wave propagation path corresponding to the ith seismic wave acquisition depth in the jth soil layer,
Figure BDA0003626241600000045
shear wave velocity of the ith soil layer, H horizontal distance between seismic wave source and borehole, and D i And t i Respectively corresponding to the ith seismic wave acquisition depth and the seismic wave transmission duration at the depth,
Figure BDA0003626241600000046
corresponding to the depth of the ith horizon boundary. The constraint conditions of the three formulas are Snell's law, the horizontal distance between the seismic wave source and the borehole and the seismic wave transmission time length respectively. Two points need to be noted here. Firstly, the shear wave velocity of each soil layer should be solved sequentially from shallow to deep in the calculation, that is, when the shear wave velocity of the ith soil layer is solved, the shear wave velocities of the first soil layer to the (i-1) th soil layer should be solved through the above formula respectively. Secondly, as can be seen from the above formula, when the shear wave velocity of the ith soil layer is solved, two cases should be distinguished: when the ith soil horizon boundary is deeper than the ith seismic wave acquisition depth, namely the ith seismic wave acquisition depth is in the ith soil layer,
Figure BDA0003626241600000047
the solution can be directly solved according to the formula without iteration; when the boundary of the ith soil layer is shallower than the acquisition depth of the ith seismic wave, namely the acquisition depth of the ith seismic wave is actually positioned in the (i + j) th soil layer, simultaneously and iteratively solving according to a forward modeling method
Figure BDA0003626241600000051
To
Figure BDA0003626241600000052
Shear wave velocity of j soil layers in total. In most cases j ≦ 3.
According to the whole process, accurate distribution of the shear wave velocity of the complex soil layer along the depth based on the seismic static sounding test can be obtained.
The invention has the beneficial effects that: the method overcomes the defect that the soil layer division for calculating the shear wave velocity in the seismic wave static sounding test data processing process must be consistent with the seismic wave acquisition interval, provides a soil body layering calculation method based on in-situ measured data, and can realize more accurate soil layer division according to the mechanical property of the soil body; the numerical iteration solving method of the shear wave velocity is provided, and the accurate distribution of the shear wave velocity along the depth can be solved according to the Snell's law and new soil body layers. Compared with the traditional method, the method aims to solve the intrinsic shear wave velocity of a certain type of soil body, so that more accurate shear stiffness is provided for analysis and numerical calculation of foundation deformation and settlement. For the engineering situation of complex soil layer composition, the method can obviously improve the calculation precision of the shear stiffness.
Drawings
FIG. 1 is a basic flow diagram of the proposed method of the present invention;
FIG. 2(a) is measured data of corrected cone tip resistance, FIG. 2(b) is measured data of side friction resistance, and FIG. 2(c) is a calculated distribution of soil property type index along depth;
FIGS. 3(a) and 3(b) are moving averages of modified cone tip resistance and soil property type index along the depth profile, respectively;
FIGS. 4(a) and 4(b) are soil type index stratification before and after optimization, respectively, and FIGS. 4(c) and 4(d) are modified cone tip resistance stratification before and after optimization, respectively;
FIG. 5(a) shows the division results of four main soil horizon boundaries; FIG. 5(b) shows three special cases to be considered according to the standard and the actual test mode in the soil layer division method;
FIG. 6 is a final soil layer division and representative properties of each soil layer in terms of soil type index;
FIG. 7 is a shear wave velocity profile obtained by this method along the depth and compared to the conventional method.
Detailed Description
The following is a combination of the drawings and the technical scheme, and a group of seismic wave static sounding test examples of a large sea reclamation project are selected to further explain the specific implementation mode of the invention. The bottom of the project is marine soft soil, the adopted sea filling material is sandy soil, the pile loading consolidation is carried out after the sand soil is filled to the target height, and the pile loading is removed and then the pile loading is compacted by power to finally form a foundation which can be used for project construction. In order to test the shear stiffness of the foundation, a seismic static sounding test is carried out, and the depth interval of seismic wave acquisition is 1 meter. The basic idea of the invention is shown in fig. 1, and for the present embodiment, the complex soil layer shear wave velocity calculation based on the seismic static cone penetration test is carried out, and the specific implementation manner is as follows:
(1) as shown in fig. 2, distribution data of corrected cone tip resistance and lateral friction resistance along the depth in the in-situ test measured data is obtained, vertical total stress and vertical effective stress are solved according to a static penetration soil classification diagram and a classical fitting relation, and then distribution data of soil property type indexes along the depth are obtained through calculation.
(2) The moving average of the corrected cone tip resistance and the soil type index was calculated by taking m to 9, and the result is shown in fig. 3.
(3) And carrying out initial layering according to the soil property type index. As shown in fig. 4(a), soil layer boundaries, whose depths have been marked in the figure, are determined according to characteristic values of soil property type indexes of 1.31, 2.05, 2.60, 2.95 and 3.6, wherein 1 meter of the top layer and 0.5 meter of the deepest layer do not participate in layering. Then, the boundary lines are merged or removed according to the relationship between the thickness of the soil layer and the thickness of the thin layer between the boundary lines and the numerical value of the soil property type index at the boundary lines, and the result is shown in fig. 4 (b).
(4) And carrying out initial layering according to the change rate of the corrected cone tip resistance along the depth. First calculate D qt Distributed along the depth. As shown in FIG. 4(c), take D qt D > 5 qt The extrema are soil boundaries whose depth has been marked in the figure, where the top 1 m and deepest 0.5 m do not participate in the layering. Then, the boundaries are merged according to the relationship between the boundary line soil layer thickness and the thin layer thickness, and the result is shown in fig. 4 (d).
(5) And classifying the soil layer boundary obtained in the two steps. Dividing the horizon boundary into a prominent boundary, a trial boundary, and I according to a determination criterion based on the initial horizon division results of FIGS. 4(b) and 4(d) c Boundary line and q t The results are shown in FIG. 5 (a).
(6) And solving the final soil layer division form. First, according to the specification requirements and the actual test manner, considering three typical cases shown in fig. 5(b), soil boundary merging or removal is performed, and considering the following two cases: removing I within 0.5 m of the significant or experimental boundary c Boundary line and q t A boundary line; removing a significant boundary within 0.5 meters of the test boundary. WhileLater, when there is no horizon boundary within 0.5 m of the seismic wave collection depth, an auxiliary boundary is added at this depth. The final division of the soil horizon boundary in this example is shown in figure 6. It can be seen that the strata with the depth of 17 meters are divided into 17 soil layers by 16 soil layer boundaries. The soil layer classification method can enable the number of soil layers to be consistent with the number of seismic wave acquisition tests, so that the determinacy of shear wave velocity calculation is ensured. Moreover, the soil layers divided by the method are representative, and the soil layers with engineering characteristics different from the surrounding soil bodies can be accurately divided, but the soil layers are not only layered according to the average depth in the traditional method, so that the obtained soil layer shear wave velocity belongs to the soil bodies with certain properties, and the method is more accurate and representative.
(7) According to the Snell's law, the actually measured seismic wave transmission duration and the new soil body layering, the shear wave velocity is solved by applying the forward simulation method numerical iteration, and the result is shown in FIG. 7. As can be seen from comparative analysis, the method provided by the invention can obviously improve the calculation accuracy of the shear wave velocity, and can obtain the intrinsic shear wave velocity of the soil body with certain engineering characteristics, rather than the average value along the depth. The invention can provide an important technical means for method optimization and precision improvement of the data analysis technology of the seismic wave static sounding test.

Claims (1)

1. A complex soil layer shear wave velocity calculation method based on a seismic wave static sounding test is characterized in that a soil body is divided into layers by applying a corrected cone tip resistance and a soil property type index, and refraction path analysis is carried out on a new soil body layer through a snell's law and actually measured seismic wave transmission time to obtain the intrinsic shear wave velocity of each soil layer, so that the calculation accuracy of the seismic wave static sounding test on the complex soil layer shear stiffness is greatly improved; the method comprises the following steps:
the method comprises the following steps: initial parameter acquisition and calculation
(1) Obtaining corrected cone tip resistance q in single group of measured data t And side friction resistance f s Distributing data along the depth, assigning an SBT value to the data at each depth according to the static penetration soil classification chart, and calculating each depth by applying a fitting relation tableSoil mass volume weight at degree:
Figure FDA0003626241590000011
(2) calculating the vertical total stress sigma according to the volume weight of the soil body, the water level line and the additional load of the field v0 And vertical effective stress σ v0 Distribution along depth, and calculation of soil property type index I according to the following formula c And (3) distribution along the depth:
I c ＝[(3.47-log Q t ) 2 +(log F r +1.22) 2 ] 0.5 ，
Figure FDA0003626241590000012
in the formula, Q t Is the normalized cone tip resistance, F r Is the side molar ratio;
step two: calculating a moving average of each parameter
(3) In order to reduce the influence of local data errors caused by influence factors on an analysis result, moving average solving is carried out on all parameters:
Figure FDA0003626241590000013
in the formula, P k The kth reading represents a certain parameter P, m represents the number of readings contained forwards and backwards in the process of solving the moving average, and m is 9;
step three: identification of boundary of four major soil layers
(4) According to I c Layering the soil body along the depth distribution curve to determine the depth of the boundary of the soil layer; i at the boundary c The characteristic values are 1.31, 2.05, 2.60, 2.95 and 3.6, and the surface layer is 1 m and the deepest layer is 0.5 m, which do not participate in layering; defining five times the bit diameter as the thickness of the thin layer; if the distance between the boundary lines of two adjacent soil layers is less than the thickness of the thin layer, and I c If the characteristic values are the same, the two boundary lines are definedAll need to be removed; if the distance between two or more adjacent soil layer boundary lines is less than the thickness of the thin layer and has increasing or decreasing I c The characteristic values are combined into one part at the average depth of the boundary lines;
(5) when q is t The rate of change along the depth being above a certain value means a change in the nature of the soil mass, passing through q t Dividing soil layers according to the change rate of the value along the depth; definition of q t Rate of change along the depth of D qt The expression is as follows:
Figure FDA0003626241590000021
wherein (q) t ) i And D i An ith reading representing modified cone tip resistance and depth, respectively; will D qt Is set to 5, i.e. when adjacent q t When the difference of the readings is more than 5 percent, the soil body property is considered to be in transition change, and D is taken gt D > 5 gt The extreme value is used as a soil layer boundary; the surface layer is 1 meter and the deepest 0.5 meter do not participate in layering; if the distance between the boundary lines of two adjacent soil layers is smaller than the thickness of the thin layer, combining the two soil layers into one position, wherein the position is at the average depth of the two soil layers;
(6) classifying the soil layer boundary obtained in the two steps; first, when applying I c Demarcating and applying q t When the distance between the divided boundary lines is smaller than the thickness of the thin layer, combining the two boundary lines, and defining a new boundary line as a remarkable boundary line, wherein the position of the remarkable boundary line is at the average depth of the two boundary lines; secondly, when the depth of a certain boundary line from the acquisition depth of the seismic waves is smaller than the thickness of the thin layer, moving the boundary line to the acquisition depth of the seismic waves, and defining the boundary line as a test boundary line; finally, defining soil layer boundary lines which do not conform to the two soil layer boundaries as I according to the division form c Boundary line and q t A boundary line;
step four: final division of soil horizon boundary
(7) Dividing the four soil layer boundary lines obtained in the previous step as follows: when adjacent to I c BoundaryOr significant demarcation line spacing less than 0.5 m and I c When the values are the same, both need to be removed; when adjacent to I c Boundary or significant boundary spacing of less than 0.5 m and I c When the values are different, the two are merged at the average depth; when more than three adjacent places I c The distance between the boundary lines or the obvious boundary lines is less than 0.5 m, only the top boundary line and the bottom boundary line are reserved, and the inner boundary line is removed; removing I within 0.5 m of the significant or experimental boundary c Boundary line and q t A boundary line; removing a significant boundary line with the distance to the test boundary line within 0.5 m;
(8) when no soil layer boundary exists within 0.5 m of the seismic wave acquisition depth, adding an auxiliary boundary at the depth to enable the number of newly divided soil layers to be equal to the number of seismic wave acquisition tests;
step five: numerical iterative solution of shear wave velocity
(9) The shear wave velocity is solved by applying the Snell's law, the actually measured seismic wave transmission duration and the new soil body layering, and the specific formula is as follows:
Figure FDA0003626241590000022
Figure FDA0003626241590000031
Figure FDA0003626241590000032
in the formula (I), the compound is shown in the specification,
Figure FDA0003626241590000033
the refraction angle of the seismic wave propagation path corresponding to the ith seismic wave acquisition depth in the jth soil layer,
Figure FDA0003626241590000034
shear wave velocity of the ith soil layer, H horizontal distance between seismic wave source and borehole, and D i And t i Respectively corresponding to the ith seismic wave acquisition depth and the seismic wave transmission duration at the depth,
Figure FDA0003626241590000035
depth corresponding to the ith soil horizon boundary; the constraint conditions of the three formulas are Snell's law, the horizontal distance between the seismic wave source and the borehole and the seismic wave transmission duration respectively; there are two points to note here: firstly, the shear wave velocity of each soil layer is sequentially solved from shallow to deep in the calculation, namely when the shear wave velocity of the ith soil layer is solved, the shear wave velocities of the first soil layer to the (i-1) th soil layer are respectively solved through the formula; secondly, as can be seen from the above formula, when the shear wave velocity of the ith soil layer is solved, two cases should be distinguished: when the ith soil horizon boundary is deeper than the ith seismic wave acquisition depth, namely the ith seismic wave acquisition depth is in the ith soil layer,
Figure FDA0003626241590000036
the solution can be directly solved according to the formula without iteration; when the boundary of the ith soil layer is shallower than the acquisition depth of the ith seismic wave, namely the acquisition depth of the ith seismic wave is actually positioned in the (i + j) th soil layer, simultaneously and iteratively solving according to a forward modeling method
Figure FDA0003626241590000037
To
Figure FDA0003626241590000038
Shear wave velocities of a total of j soil layers; in most cases j ≦ 3.
CN202210477037.8A 2022-05-03 2022-05-03 Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test Pending CN114839678A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210477037.8A CN114839678A (en) 2022-05-03 2022-05-03 Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210477037.8A CN114839678A (en) 2022-05-03 2022-05-03 Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test

Publications (1)

Publication Number Publication Date
CN114839678A true CN114839678A (en) 2022-08-02

Family

ID=82568229

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210477037.8A Pending CN114839678A (en) 2022-05-03 2022-05-03 Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test

Country Status (1)

Country Link
CN (1) CN114839678A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116559956A (en) * 2023-04-28 2023-08-08 上海勘测设计研究院有限公司 Submarine seismic wave testing equipment and method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116559956A (en) * 2023-04-28 2023-08-08 上海勘测设计研究院有限公司 Submarine seismic wave testing equipment and method
CN116559956B (en) * 2023-04-28 2024-04-16 上海勘测设计研究院有限公司 Submarine seismic wave testing equipment and method

Similar Documents

Publication Publication Date Title
CN106368691B (en) Three-dimensional abnormal pore pressure prediction method based on rock physics seismic information
CN103258091B (en) Unconventionaloil pool hides the method and device that net horizontal section three-dimensional mechanical models for rock mass is set up
CN106094022B (en) A kind of measuring method of soil layer mean shear wave velocity and soil layer reflecting interface buried depth
CN107066771B (en) Horizontal-pushing type landslide movement distance calculation method and application
CN104047597A (en) Fat gas mud shale stratum well log standardizing method
CN112686779B (en) Method for dividing sequence of standard soil layers of foundation soil
CN108089227B (en) Novel stratum pore pressure prediction method based on three-dimensional seismic data
CN104267429A (en) Method and device for determining formation pressure
CN105093307B (en) The oblique true formation thickness acquiring method of Lower Paleozoic strata
CN103914620B (en) Method for computing distribution of opening spaces of fractures of fault rupture zones
CN108663713B (en) Method for establishing depth domain structure model
CN105277982A (en) Shale total organic carbon content earthquake prediction method
CN105005077A (en) Thin layer thickness prediction method with combination of real drilling wells and virtual wells under rare well condition
CN105093311A (en) Stratum denudation thickness measurement method for superposition basin multi-phase difference upheaval region
Sauvin et al. Machine learning and quantitative ground models for improving offshore wind site characterization
CN111812707A (en) Method for detecting boulders in subway line site based on micro-motion and surface wave exploration
CN109458176A (en) The prediction technique and its application of carbonate reservoir pressure
CN114839678A (en) Complex soil layer shear wave velocity calculation method based on seismic wave static cone penetration test
CN102288996A (en) Method for quantificationally predicting gas containing probability through prestack automatic fault indication (AFI) inversion
CN112185469B (en) Method for predicting favorable gathering area of sea natural gas hydrate
CN112177605B (en) Method for determining main control factors of favorable gathering area of sea natural gas hydrate
CN112049631A (en) Sea phase shale high-quality reservoir prediction method based on source rock-reservoir-brittleness analysis
CN110989034B (en) Method for inverting logging transverse wave time difference by regression-fractal interpolation method
Biryaltseva et al. Relative densities and void ratios derived from CPT data using in situ field calibration
CN110080197B (en) Lanzhou red sandstone classification method and corresponding engineering measure selection method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination