CN108986213B - Three-dimensional stratum modeling method based on stacking technology - Google Patents

Abstract

The invention discloses a three-dimensional formation modeling method based on superposition technology. The main processing steps include: (1) processing original borehole data; (2) extracting terrain feature points from high-precision DEM in the modeling area; (3) Construct topographic feature virtual boreholes; (4) Discrete modeling area range; (5) Construct initial triangulation; (6) Adaptive encryption processing; (7) Stratigraphic pinch-out processing; Construction of engineering geological body GTP model. Compared with the traditional method, the method of the present invention has higher accuracy in constructing the model.

Description

Three-dimensional stratum modeling method based on stacking technology

Technical Field

The invention relates to the field of geographic information technology application, in particular to a three-dimensional stratum modeling method based on a superposition technology.

Background

In recent years, under the support of GIS technology and computer technology, the modeling technology of urban three-dimensional stratums is greatly developed, and various three-dimensional data models and modeling methods suitable for different engineering geological environments are researched. The main data source for constructing the three-dimensional stratum model is engineering borehole data, but is limited by the cost of engineering drilling, and the borehole data which can be acquired is often sparse and unevenly distributed, so that the three-dimensional model constructed only according to the original sampling point data is not accurate enough. Aiming at the problem, the concept of virtual holes is introduced into Zhuliangfeng and the like and is applied to the actual three-dimensional modeling process, so that the problem that a relatively complete and accurate three-dimensional model cannot be constructed by limited drilling data is efficiently solved (see Zhuliangfeng, Wu Xincai, Liu Xiu Guo, and the like, the introduction and realization of the virtual holes in the urban three-dimensional stratum modeling [ J ]. the science of geographic and geographic information, 2004,20(6): 26-30.). On the basis of the virtual hole concept, other various three-dimensional stratum modeling methods appear in succession, and good improvement effects are achieved.

The three-dimensional stratum modeling is actually to construct each stratum on the basis of the stratum hierarchical relation, and is similar to the method for constructing the DEM based on sampling point data, and the key point is to find out the terrain characteristic points of each stratum and use the terrain characteristic points to control the stratum form. However, in the existing modeling method, the topographic features of the stratum are not considered, and under many conditions, the accuracy of the model constructed by the existing method is reduced, especially when the topographic relief of the modeling area is large. For this purpose, a terrain feature virtual borehole can be constructed by the terrain feature points of the stratum and added to the modeling process for controlling the formation morphology to solve. The key to the problem is how to find out the formation topography feature points and calculate the topography feature virtual borehole formation properties. In nature, many adjacent formation layers have similarities to each other, and new formations may take on the same or similar morphology as old formations. Therefore, the terrain feature points of the earth surface strata are the terrain feature points of the rest strata, and the terrain feature virtual borehole stratum attributes can be calculated by using the superposition technology.

Disclosure of Invention

The purpose of the invention is as follows: the invention provides a three-dimensional stratum modeling method based on a superposition technology, aiming at the problem that a three-dimensional stratum model constructed in an area with large topographic relief by the existing three-dimensional stratum modeling method has larger difference compared with a real stratum.

The technical scheme is as follows: the three-dimensional stratum modeling method based on the stacking technology comprises the following steps:

(1) reading original drilling data in the modeling area into an original drilling data set, and adding missing strata to original drilling holes in the original drilling data set according to a standard stratum sequence table;

(2) extracting terrain feature points from the high-precision DEM of the modeling area to obtain a feature point set;

(3) according to the feature point set, constructing a terrain feature virtual drilling hole, and adding the virtual drilling hole into an original drilling hole data set to form a first drilling hole data set;

(4) carrying out grid discretization on the range of the modeling area, constructing an interpolation virtual drilling hole at a boundary point, and adding the interpolation virtual drilling hole into the first drilling hole data set to form a second drilling hole data set;

(5) establishing an initial triangulation network by taking the range of the modeling area as a constraint condition, taking the coordinates of the original drilling hole, the topographic feature virtual drilling hole and the interpolation virtual drilling hole as datum points and adopting a standard D-TIN construction algorithm;

(6) according to the second drilling data set, carrying out encryption processing on a triangle containing topographic feature points in the initial triangulation network to generate a self-adaptive encryption processing triangulation network, wherein the drilling data after the self-adaptive encryption processing form a third drilling data set;

(7) carrying out stratum pinch-out treatment on the self-adaptive encryption processing triangular net by adopting a stratum pinch-out treatment strategy according to the third drilling data set to generate a stratum pinch-out processing triangular net, wherein the drilling data after the stratum pinch-out treatment form a fourth drilling data set;

(8) and constructing an engineering geological body GTP model according to the stratum pinch-out processing triangular net.

Further, the step (1) specifically comprises:

(1-1) reading original drilling data and corresponding drilling stratum data in the modeling area, and storing the data into an original drilling data set AD ═ AD _i1, 2., m }, where ad_iRepresenting the ith original borehole, ad_i＝{lc_i，stglist_i}，lc_iIs ad_iInformation, stglist_iIs ad_iThe corresponding drilling stratum list stores the serial number, the layer top depth, the layer bottom depth and the stratum of each drilling stratumDepth, m is the original number of drilled holes;

(1-2) obtaining a standard stratum number stmcnt according to a standard stratum sequence table, and performing the following treatment on the drill holes with the total number of the drill stratum in AD being less than the standard stratum number stmcnt: and constructing a virtual stratum for the missing stratum in the drilling stratum of the drilling hole, setting the serial number of the virtual stratum as the serial number of the missing stratum, setting the top layer depth and the bottom layer depth of the missing stratum as the bottom layer depth of the adjacent stratum, and adding the virtual stratum information into the drilling stratum list of the drilling hole.

Further, the step (2) specifically comprises:

(2-1) reading a high-precision DEM of the modeling area, and recording as DEM;

(2-2) setting the width of the topographic feature point extraction window to W_wHigh is W_h；

And (2-3) extracting the topographic feature points from the dem by utilizing a topographic feature point extraction algorithm based on a surface water flow simulation method based on the set feature point extraction window, and storing the topographic feature points in a topographic feature point set TP.

Further, the step (3) specifically comprises:

(3-1) for each feature point in the feature point set TP, constructing a terrain feature virtual drilling hole according to the coordinate of the feature point, and storing the virtual drilling hole into a terrain feature virtual drilling hole set TD;

(3-2) constructing a two-dimensional drilling hole kd tree according to the abscissa and the ordinate of the original drilling hole position in the original drilling hole data set AD;

(3-3) setting the search radius and the maximum search number as c and k respectively, and adding virtual stratums to all virtual drill holes in the terrain feature virtual drill hole set TD by using the original drill hole data set AD as a data source and using an overlaying technology according to the established kd tree;

(3-4) adding all virtual drilling holes in the TD processed in the step (3-3) into the set AD to obtain a first drilling data set AD₁。

Further, the step (3-3) specifically comprises:

(3-3-1) setting the search radius and the maximum search number as c and k respectively;

(3-3-2) acquiring any virtual drilling hole in the topographic feature virtual drilling hole set TD;

(3-3-3) searching k adjacent original boreholes from the kd tree by using a KNN algorithm according to the coordinates of the virtual boreholes, and storing the k adjacent original boreholes in an adjacent borehole set ND;

(3-3-4) adding virtual stratums to the virtual borehole one by taking the adjacent borehole set ND as a data set according to a standard stratum sequence table, wherein the specific processing steps are as follows: constructing virtual stratums, calculating the layer top depth, the layer bottom depth and the stratum depth of each virtual stratum by using a stacking technology, and then adding virtual stratum information into a drilling stratum list of the virtual drilling hole;

and (3-3-5) returning to the step (3-3-2) until all the virtual drill holes in the terrain feature virtual drill hole set TD are traversed.

Further, the step (4) specifically comprises:

(4-1) reading the modeling area range data roi;

(4-2) carrying out grid discrete processing on the roi according to the set discrete distance d of the modeling area, and storing the obtained discrete points into a discrete point set DP;

(4-3) reading the data of the boundary point of the modeling area from the discrete point set DP and storing the data in the set DP₁；

(4-4) traversing the set DP₁All the points construct interpolation virtual drill holes according to the coordinates of the points, and the interpolation virtual drill holes are stored in an interpolation virtual drill hole set DD;

(4-5) adding virtual stratums to all the interpolation virtual boreholes in the interpolation virtual borehole set DD one by one, wherein the specific processing steps are as follows: utilizing a first set of borehole data AD₁Fitting the layer top depth and the layer bottom depth of the virtual stratum of the interpolated virtual drill hole by adopting an IDW spatial interpolation algorithm, calculating the difference value of the virtual drill hole elevation and the layer bottom depth as the stratum depth, and then adding the virtual stratum information into a drill hole stratum list of the drill hole;

(4-6) adding all interpolated virtual boreholes in the set DD to the first set of borehole data AD₁In (1), a second borehole data set AD is obtained₂。

Further, the step (6) specifically comprises:

(6-1) initializing adaptive encryption processing triangulation network T_eAs an empty set, a third borehole data set AD₃＝AD₂；

(6-2) reading the initial triangulation network T₀One triangle of (1);

(6-3) judging whether the end points of the triangle contain the terrain feature points, and if so, executing the step (6-4); otherwise, the triangle is directly added to the adaptive encryption processing triangular network T_ePerforming step (6-6);

(6-4) acquiring the middle points of each side of the triangle, connecting the three middle points by adopting straight lines, dividing the triangle into four small encrypted triangles, and adding the four small encrypted triangles into a self-adaptive encryption processing triangular network T_ePerforming the following steps;

(6-5) constructing self-adaptive encrypted virtual drill holes in the middle points of all sides of the triangle, calculating the stratum information of the self-adaptive encrypted virtual drill holes according to the stratum information of the drill holes in the end points of all sides of the triangle, and storing the self-adaptive encrypted virtual drill holes into a third drill hole data set AD₃Performing the following steps;

(6-6) executing the steps (6-2) to (6-5) circularly until the initial triangulation network T is processed₀All the triangulation networks are in the same network, and the final adaptive encryption processing triangulation network T is obtained_eAnd a third borehole data set AD₃。

Further, the step (7) specifically comprises:

(7-1) traversal adaptive encryption processing triangular network T_eConstructing a stratum pinch-out treatment virtual borehole at a pinch-out point according to a pinch-out rule on all triangular edges;

(7-2) AD from the third borehole data set₃In-acquisition adaptive encryption processing triangular network T_eStratum information of the boreholes at two ends of the middle triangular edge is used for calculating the stratum information of the virtual borehole processed by pinch-out of the stratum and adding the virtual borehole processed by pinch-out into a third borehole data set AD₃In (5), a fourth borehole data set AD is obtained₄The triangular net after the stratum pinch-out treatment is recorded as T_a。

Further, the step (8) specifically comprises:

(8-1) obtaining stratum pinch-out processing triangular net T_aObtaining the coordinates of three end points of any triangle, and according to the coordinates, obtaining the coordinates from the fourth drilling data set AD₄Obtaining three drilling holes positioned at the end points of the triangle;

(8-2) traversing all stratums in the three drill holes according to the standard stratum sequence, and constructing GTP by taking the top plate depth of each layer as the vertex coordinate of the triangle on GTP, the bottom plate depth of each layer as the vertex coordinate of the triangle under GTP and the stratum lithology number as the GTP attribute;

(8-3) repeating the steps (8-1) and (8-2) until the stratum pinch-out processing triangular net T is traversed_aAnd all the triangles complete the construction of the three-dimensional stratum model in the modeling area.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: aiming at three-dimensional stratum modeling of an area with large topographic relief, extracting topographic feature points from a high-precision DEM (dynamic effect model) of a modeling area; secondly, constructing a virtual drilling hole of the topographic feature points, and calculating the stratum attribute of the drilling hole by using a stacking technology; and then, adding the virtual drilling holes of the topographic feature points into the modeling drilling holes for controlling the formation form, and discussing and realizing a three-dimensional modeling method which can be constructed to be closer to the real formation form. The invention has the advantages of low algorithm complexity, high automation degree and good modeling quality.

Drawings

FIG. 1 is a flow chart of a method for modeling a three-dimensional formation based on stacking techniques provided by the present invention;

FIG. 2 is a data structure diagram of a borehole and formation;

FIG. 3 is a raw borehole spatial distribution map;

FIG. 4 is a modeled area 5 meter resolution DEM plot;

FIG. 5 is a topographical feature point spatial distribution map;

FIG. 6 is an interpolated virtual borehole spatial distribution map;

FIG. 7 is a schematic view of an initial triangulation network;

FIG. 8 is a diagram of a triangle encryption process;

FIG. 9 is a schematic view of a triangulation network after a formation pinch-out treatment;

FIG. 10 is a three-dimensional stratigraphic model diagram.

Detailed Description

The embodiment provides a three-dimensional stratum modeling method based on a stacking technique, as shown in fig. 1, including:

(1) reading the original drilling data in the modeling area into an original drilling data set, and adding missing strata to original drilling in the original drilling data set according to a standard stratum sequence table.

The method specifically comprises the following steps:

(1-1) reading original drilling data and corresponding drilling stratum data in the modeling area, and storing the data into an original drilling data set AD ═ AD _i1, 2., m }, where ad_iRepresenting the ith original borehole, ad_i＝{lc_i,stglist_i}，lc_iIs ad_iInformation, stglist_iIs ad_iAnd the corresponding drilling stratum list stores the serial number, the layer top depth, the layer bottom depth and the stratum depth of each drilling stratum, and m is the number of the original drilling holes. The specific data structure and relationship of the borehole information and the borehole formation information are shown in fig. 2.

For example, a certain region of Nanjing is taken as a modeling region, 51 original drilling hole data of the region are taken as modeling data, 5 m resolution DEM is taken as topographic feature point extraction data for model construction, 51 original drilling holes and corresponding drilling hole stratum data are read from the modeling region, and a set AD ═ { AD ═ is obtained_i1,2, 51}, the original borehole spatial distribution is as shown in fig. 3.

(1-2) obtaining a standard stratum number stmcnt according to a standard stratum sequence table, and performing the following treatment on the drill holes with the total number of the drill stratum in AD being less than the standard stratum number stmcnt: and constructing a virtual stratum for the missing stratum in the drilling stratum of the drilling hole, setting the serial number of the virtual stratum as the serial number of the missing stratum, setting the top layer depth and the bottom layer depth of the missing stratum as the bottom layer depth of the adjacent stratum, and adding the virtual stratum information into the drilling stratum list of the drilling hole. Wherein, the standard stratum sequence is shown in the table 1,

TABLE 1

For example, as the above example, the standard formation number stmcnt is 7, and thus, 44 original boreholes with formation missing are processed in total.

(2) And extracting terrain feature points from the high-precision DEM of the modeling area to obtain a feature point set.

The method specifically comprises the following steps:

(2-1) reading a high-precision DEM of the modeling area, and recording as DEM;

(2-2) setting the width of the topographic feature point extraction window to W_wHigh is W_h；

And (2-3) extracting the topographic feature points from the dem by utilizing a topographic feature point extraction algorithm based on a surface water flow simulation method based on the set feature point extraction window, and storing the topographic feature points in a topographic feature point set TP.

For example, as the above example, the DEM of the modeling area with the resolution of 5 meters is read to obtain DEM as shown in fig. 4; width W of the arrangement_w15, high W_h15, in the embodiment, 187 topographical feature points are extracted from dem, and the set TP ═ TP is obtained_i1, 2.., 187}, and the spatial distribution of the topographic feature points is shown in fig. 5.

(3) And constructing a terrain feature virtual drilling hole according to the feature point set, and adding the virtual drilling hole into the original drilling hole data set to form a first drilling hole data set.

The method specifically comprises the following steps:

and (3-1) for each feature point in the feature point set TP, constructing a terrain feature virtual drilling hole according to the coordinate of the feature point, and storing the virtual drilling hole into a terrain feature virtual drilling hole set TD. In the above example, 187 virtual boreholes with topographic features are constructed, and the set TD ═ TD is obtained_i|i＝1,2,...,187}；

(3-2) constructing a two-dimensional drilling hole kd tree according to the abscissa and the ordinate of the original drilling hole position in the original drilling hole data set AD; wherein, the kd tree construction method is described in Finley A O, Mcrroberts R E. efficient k-near neighbor searches for multi-source for attribute mapping [ J ]. Remote Sensing of environmental, 2008,112(5): 2203-.

And (3-3) setting the search radius and the maximum search number as c and k respectively, and adding virtual stratums to all virtual drill holes in the terrain feature virtual drill hole set TD by using the original drill hole data set AD as a data source and using an overlaying technology according to the established kd tree. The specific process is as follows:

A. setting the search radius and the maximum search number as c and k respectively;

B. acquiring any virtual drilling hole in a topographic feature virtual drilling hole set TD;

C. searching k adjacent original drill holes from the kd tree by using a KNN algorithm according to the coordinates of the virtual drill holes, and storing the k adjacent original drill holes into an adjacent drill hole set ND; among them, the KNN algorithm is described in Finley A O, Mcrroberts R E. efficient k-nearest neighbor searches for multi-source for attribute mapping [ J ]. removal Sensing of Environment,2008,112(5): 2203-;

D. adding virtual stratums to the virtual drill holes one by taking an adjacent drill hole set ND as a data set according to a standard stratum sequence list, wherein the specific processing steps are as follows: constructing virtual stratums, calculating the layer top depth, the layer bottom depth and the stratum depth of each virtual stratum by using a stacking technology, and then adding virtual stratum information into a drilling stratum list of the virtual drilling hole; wherein, the stacking technique is described in Tearpock D J, Bischke R E.applied sub surface geographic Mapping with Structural Methods [ J ]. Applied sub surface geographic Mapping with Structural Methods,1990,322(3): 311-;

E. and returning to the step B until all the virtual drill holes in the terrain feature virtual drill hole set TD are traversed.

For example, in the above example, the cable radius c is set to 1000, the maximum number of search parameter k is set to 12, 187 virtual boreholes in the set TD are processed in total, and 7 virtual earth formations are added to each borehole.

(3-4) processing all virtual drilled holes in the TD processed in the step (3-3)Adding the data into the set AD to obtain a first drilling data set AD₁。

For example, following the example, the resulting first borehole data set AD₁＝{ad_1i|i＝1,2,...,238}。

(4) And carrying out grid discretization on the range of the modeling area, constructing an interpolation virtual drilling hole at the boundary point, and adding the interpolation virtual drilling hole into the first drilling hole data set to form a second drilling hole data set.

The method specifically comprises the following steps:

(4-1) reading the modeling area range data roi;

(4-2) carrying out grid discrete processing on the roi according to the set discrete distance d of the modeling area, and storing the obtained discrete points into a discrete point set DP;

(4-3) reading the data of the boundary point of the modeling area from the discrete point set DP and storing the data in the set DP₁；

(4-4) traversing the set DP₁All the points construct interpolation virtual drill holes according to the coordinates of the points, and the interpolation virtual drill holes are stored in an interpolation virtual drill hole set DD;

(4-5) adding virtual stratums to all the interpolation virtual boreholes in the interpolation virtual borehole set DD one by one, wherein the specific processing steps are as follows: utilizing a first set of borehole data AD₁Fitting the layer top depth and the layer bottom depth of the virtual stratum of the interpolated virtual drill hole by adopting an IDW spatial interpolation algorithm, calculating the difference value of the virtual drill hole elevation and the layer bottom depth as the stratum depth, and then adding the virtual stratum information into a drill hole stratum list of the drill hole;

(4-6) adding all interpolated virtual boreholes in the set DD to the first set of borehole data AD₁In (1), a second borehole data set AD is obtained₂。

For example, in the following example, the discrete pitch parameter d is set to 200, and the discrete point set DP is obtained as { DP ═ DP _i1, 2.,. 225}, reading 116 modeling area boundary point data from the discrete point set DP to obtain a boundary point set DP₁＝{dp _1i1,2, 116, and then constructing an interpolation virtual drilling hole for the boundary point to obtain a set DD { DD ═ DD ·_i|i＝1,2,..,341} the interpolated virtual borehole spatial distribution is as shown in fig. 6, adding all interpolated virtual boreholes in the set DD to the first set of borehole data AD₁In (1), a second borehole data set AD is obtained₂＝{ad_2i|i＝1，2，...,579}。

(5) And establishing an initial triangulation network by taking the range of the modeling area as a constraint condition, taking the coordinates of the original drilling hole, the topographic feature virtual drilling hole and the interpolation virtual drilling hole as datum points and adopting a standard D-TIN construction algorithm. In the above example, an initial triangulation network T was constructed₀As shown in fig. 7, there are 1809 triangles.

(6) And according to the second drilling data set, carrying out encryption processing on the triangle containing the topographic feature points in the initial triangulation network to generate a self-adaptive encryption processing triangulation network, wherein the drilling data after the self-adaptive encryption processing form a third drilling data set.

The method specifically comprises the following steps:

(6-1) initializing adaptive encryption processing triangulation network T_eAs an empty set, a third borehole data set AD₃＝AD₂；

(6-2) reading the initial triangulation network T₀One triangle of (1);

(6-3) judging whether the end points of the triangle contain the terrain feature points, and if so, executing the step (6-4); otherwise, the triangle is directly added to the adaptive encryption processing triangular network T_ePerforming step (6-6);

(6-4) acquiring the middle points of each side of the triangle, and connecting the three middle points by adopting straight lines as shown in fig. 8, thereby dividing the triangle into four small encrypted triangles, and adding the four small encrypted triangles to the adaptive encryption processing triangular network T_ePerforming the following steps;

(6-5) constructing self-adaptive encrypted virtual drill holes in the middle points of all sides of the triangle, calculating the stratum information of the self-adaptive encrypted virtual drill holes according to the stratum information of the drill holes in the end points of all sides of the triangle, and storing the self-adaptive encrypted virtual drill holes into a third drill hole data set AD₃Performing the following steps;

(6-6) executing the steps (6-2) to (6-5) circularly until the initial triangulation network T is processed₀All the triangulation networks are in the same network, and the final adaptive encryption processing triangulation network T is obtained_eAnd a third borehole data set AD₃。

Taking the example above, the initial triangulation network T₀1809 triangles are subjected to self-adaptive encryption processing to 748 triangles containing terrain feature points to obtain a set AD₃＝{ad_3i|i＝1，2,...，2823}。

(7) And carrying out stratum pinch-out treatment on the self-adaptive encryption processing triangular net by adopting a stratum pinch-out treatment strategy according to the third drilling data set to generate a stratum pinch-out processing triangular net, wherein the drilling data after the stratum pinch-out treatment form a fourth drilling data set.

The method specifically comprises the following steps

(7-1) traversal adaptive encryption processing triangular network T_eConstructing a stratum pinch-out treatment virtual borehole at a pinch-out point according to a pinch-out rule on all triangular edges;

(7-2) AD from the third borehole data set₃In-acquisition adaptive encryption processing triangular network T_eStratum information of the boreholes at two ends of the middle triangular edge is used for calculating the stratum information of the virtual borehole processed by pinch-out of the stratum and adding the virtual borehole processed by pinch-out into a third borehole data set AD₃In (5), a fourth borehole data set AD is obtained₄The triangular net after the stratum pinch-out treatment is recorded as T_a。

Following the example, adaptive encryption processes the triangulation network T_e4053 triangles in total, and the set AD obtained after pinch-out treatment₄＝{ad _4i1, 2., 4290}, triangulation network T after formation pinch-out treatment_aAs shown in fig. 9.

(8) And constructing an engineering geological body GTP model according to the stratum pinch-out processing triangular net.

The method specifically comprises the following steps:

(8-1) obtaining stratum pinch-out processing triangular net T_aObtaining the coordinates of three end points of any triangle, and according to the coordinates, obtaining the coordinates from the fourth drilling data set AD₄Obtaining three drilling holes positioned at the end points of the triangle;

(8-2) traversing all stratums in the three drill holes according to the standard stratum sequence, and constructing GTP by taking the top plate depth of each layer as the vertex coordinate of the triangle on GTP, the bottom plate depth of each layer as the vertex coordinate of the triangle under GTP and the stratum lithology number as the GTP attribute;

(8-3) repeating the steps (8-1) and (8-2) until the stratum pinch-out processing triangular net T is traversed_aAnd all the triangles complete the construction of the three-dimensional stratum model in the modeling area.

In the above example, 6610 triangles in total are modeled in the triangular mesh Ta after the formation pinch-out treatment, and a GTP model containing 7 formations in total as shown in (a) and (c) in fig. 10 is obtained. FIGS. 10 (b) and (d) show the GTP models of engineered geobodies constructed by conventional methods. Comparing the graph (a) with the graph (c), it can be seen that the surface state of the model shown in the graph (a) is closer to the surface state represented by the DEM; comparing the graph (b) with the graph (d), it can be seen that the gross morphology of the adjacent strata of the model shown in the graph (b) is similar to each other, and is more consistent with the geographical rules. Therefore, the three-dimensional stratum modeling method based on the superposition technology can better solve the problem that a geologic body model constructed in an area with large topographic relief by the existing three-dimensional stratum modeling method has larger difference compared with a real stratum.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (9)

1. A three-dimensional stratum modeling method based on a stacking technology is characterized by comprising the following steps:

(1) reading original drilling data in the modeling area into an original drilling data set, and adding missing strata to original drilling holes in the original drilling data set according to a standard stratum sequence table;

(2) extracting terrain feature points from the high-precision DEM of the modeling area to obtain a feature point set;

(3) according to the feature point set, constructing a terrain feature virtual drilling hole, and adding the virtual drilling hole into an original drilling hole data set to form a first drilling hole data set;

(4) carrying out grid discretization on the range of the modeling area, and after constructing an interpolation virtual drilling hole at the boundary point, adding the interpolation virtual drilling hole into the first drilling hole data set to form a second drilling hole data set;

(5) establishing an initial triangulation network by taking the range of the modeling area as a constraint condition, taking the coordinates of the original drilling hole, the topographic feature virtual drilling hole and the interpolation virtual drilling hole as datum points and adopting a standard D-TIN construction algorithm;

(6) according to the second drilling data set, carrying out encryption processing on a triangle containing topographic feature points in the initial triangulation network to generate a self-adaptive encryption processing triangulation network, wherein the drilling data after the self-adaptive encryption processing form a third drilling data set;

(7) carrying out stratum pinch-out treatment on the self-adaptive encryption processing triangular net by adopting a stratum pinch-out treatment strategy according to the third drilling data set to generate a stratum pinch-out processing triangular net, wherein the drilling data after the stratum pinch-out treatment form a fourth drilling data set;

(8) and constructing an engineering geological body GTP model according to the stratum pinch-out processing triangular net.

2. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (1) specifically comprises the following steps:

(1-1) reading original drilling data and corresponding drilling stratum data in the modeling area, and storing the data into an original drilling data set AD ═ AD_i1, 2., m }, where ad_iRepresenting the ith original borehole, ad_i＝{lc_i,stglist_i}，lc_iIs ad_iInformation, stglist_iIs ad_iThe corresponding drilling stratum list stores the serial number, the layer top depth, the layer bottom depth and the stratum depth of each drilling stratum, and m is the number of original drilling holes;

(1-2) obtaining a standard stratum number stmcnt according to a standard stratum sequence table, and performing the following treatment on the drill holes with the total number of the drill stratum in AD being less than the standard stratum number stmcnt: and constructing a virtual stratum for the missing stratum in the drilling stratum of the drilling hole, setting the serial number of the virtual stratum as the serial number of the missing stratum, setting the top layer depth and the bottom layer depth of the missing stratum as the bottom layer depth of the adjacent stratum, and adding the virtual stratum information into the drilling stratum list of the drilling hole.

3. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (2) specifically comprises the following steps:

(2-1) reading a high-precision DEM of the modeling area, and recording as DEM;

(2-2) setting the width of the topographic feature point extraction window to W_wHigh is W_h；

And (2-3) extracting the topographic feature points from the dem by utilizing a topographic feature point extraction algorithm based on a surface water flow simulation method based on the set feature point extraction window, and storing the topographic feature points in a topographic feature point set TP.

4. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (3) specifically comprises the following steps:

(3-1) for each feature point in the topographic feature point set TP, constructing a topographic feature virtual drilled hole according to the coordinate of each feature point, and storing the virtual drilled hole into a topographic feature virtual drilled hole set TD;

(3-2) constructing a two-dimensional drilling hole kd tree according to the abscissa and the ordinate of the original drilling hole position in the original drilling hole data set AD;

(3-3) setting the search radius and the maximum search number as c and k respectively, and adding virtual stratums to all virtual drill holes in the terrain feature virtual drill hole set TD by using the original drill hole data set AD as a data source and using an overlaying technology according to the established kd tree;

(3-4) adding all virtual drilling holes in the TD processed in the step (3-3) into the original drilling data set AD to obtain a first drilling data set AD₁。

5. The stacking technique based three-dimensional stratigraphic modeling method of claim 4, characterized in that: the step (3-3) specifically comprises:

(3-3-1) setting the search radius and the maximum search number as c and k respectively;

(3-3-2) acquiring any virtual drilling hole in the topographic feature virtual drilling hole set TD;

(3-3-3) searching k adjacent original boreholes from the kd tree by using a KNN algorithm according to the coordinates of the virtual boreholes, and storing the k adjacent original boreholes in an adjacent borehole set ND;

(3-3-4) adding virtual stratums to the virtual borehole one by taking the adjacent borehole set ND as a data set according to a standard stratum sequence table, wherein the specific processing steps are as follows: constructing virtual stratums, calculating the layer top depth, the layer bottom depth and the stratum depth of each virtual stratum by using a stacking technology, and then adding virtual stratum information into a drilling stratum list of the virtual drilling hole;

and (3-3-5) returning to the step (3-3-2) until all the virtual drill holes in the terrain feature virtual drill hole set TD are traversed.

6. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (4) specifically comprises the following steps:

(4-1) reading the modeling area range data roi;

(4-2) carrying out grid discrete processing on the roi according to the set discrete distance d of the modeling area, and storing the obtained discrete points into a discrete point set DP;

(4-3) reading the data of the boundary point of the modeling area from the discrete point set DP and storing the data in the set DP₁；

(4-4) traversing the set DP₁All the points construct interpolation virtual drill holes according to the coordinates of the points, and the interpolation virtual drill holes are stored in an interpolation virtual drill hole set DD;

(4-5) adding virtual stratums to all the interpolation virtual boreholes in the interpolation virtual borehole set DD one by one, wherein the specific processing steps are as follows: utilizing a first set of borehole data AD₁Fitting the layer top depth and the layer bottom depth of the virtual stratum of the interpolated virtual borehole by adopting an IDW spatial interpolation algorithm, calculating the difference value of the virtual borehole elevation and the layer bottom depth as the stratum depth, and then calculating the layer top depth and the layer bottom depth of the virtual borehole as the stratum depthAdding the virtual formation information to a borehole formation list for the borehole;

(4-6) adding all interpolated virtual boreholes in the interpolated virtual borehole set DD to the first borehole data set AD₁In (1), a second borehole data set AD is obtained₂。

7. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (6) specifically comprises the following steps:

(6-1) initializing adaptive encryption processing triangulation network T_eAs an empty set, a third borehole data set AD₃＝AD₂；

(6-2) reading the initial triangulation network T₀One triangle of (1);

(6-3) judging whether the end points of the triangle contain the terrain feature points, and if so, executing the step (6-4); otherwise, the triangle is directly added to the adaptive encryption processing triangular network T_ePerforming step (6-6);

(6-4) acquiring the middle points of each side of the triangle, connecting the three middle points by adopting straight lines, dividing the triangle into four small encrypted triangles, and adding the four small encrypted triangles into a self-adaptive encryption processing triangular network T_ePerforming the following steps;

(6-5) constructing self-adaptive encrypted virtual drill holes in the middle points of all sides of the triangle, calculating the stratum information of the self-adaptive encrypted virtual drill holes according to the stratum information of the drill holes in the end points of all sides of the triangle, and storing the self-adaptive encrypted virtual drill holes into a third drill hole data set AD₃Performing the following steps;

(6-6) executing the steps (6-2) to (6-5) circularly until the initial triangulation network T is processed₀All the triangulation networks are in the same network, and the final adaptive encryption processing triangulation network T is obtained_eAnd a third borehole data set AD₃。

8. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (7) specifically comprises:

(7-1) traversal adaptive encryption processing triangular network T_eAll ofAccording to the pinch-out rule, a stratum pinch-out treatment virtual borehole is constructed at the pinch-out point;

(7-2) AD from the third borehole data set₃In-acquisition adaptive encryption processing triangular network T_eStratum information of the boreholes at two ends of the middle triangular edge is used for calculating the stratum information of the virtual borehole processed by pinch-out of the stratum and adding the virtual borehole processed by pinch-out into a third borehole data set AD₃In (5), a fourth borehole data set AD is obtained₄The triangular net after the stratum pinch-out treatment is recorded as T_a。

9. The stacking technique based three-dimensional stratigraphic modeling method of claim 1, characterized in that: the step (8) specifically comprises:

(8-1) obtaining stratum pinch-out processing triangular net T_aObtaining the coordinates of three end points of any triangle, and according to the coordinates, obtaining the coordinates from the fourth drilling data set AD₄Obtaining three drilling holes positioned at the end points of the triangle;

(8-2) traversing all stratums in the three drill holes according to the standard stratum sequence, and constructing GTP by taking the top plate depth of each layer as the vertex coordinate of the triangle on GTP, the bottom plate depth of each layer as the vertex coordinate of the triangle under GTP and the stratum lithology number as the GTP attribute;

(8-3) repeating the steps (8-1) and (8-2) until the stratum pinch-out processing triangular net T is traversed_aAnd all the triangles complete the construction of the three-dimensional stratum model in the modeling area.

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