Ground property determination method

Abstract

To provide a ground property determination method capable of comprehending property of the entire ground more accurately.SOLUTION: A ground property determination method comprises the steps of: examining property of the ground G regarding a depth direction Z at a plurality of points in a vertical direction Y and a lateral direction X when examining the property of the ground expanding in the vertical direction, the lateral direction X, and the depth direction Z; and at examined points P adjacent to each other, identifying the ground meeting the specific conditions to connect the specific grounds N, N to each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for determining the properties of the ground.

Background Art

[0002] As methods for investigating the properties of the ground, there are various methods such as core boring, standard penetration test, dynamic penetration test, vane test, and cone penetration test. In recent years, a survey method using excavation parameters for determining ground classification and the like in combination with the above survey methods has been proposed and implemented by measuring various data during drilling and analyzing these data using a computer or the like. As a method for investigating the properties of the ground using these excavation parameters, there are a ground strength measurement method described in Patent Document 1 and a soil hardness measurement method for an excavation auger described in Patent Document 2.

[0003] However, all of these methods require penetration work such as drilling the ground or conducting a boring survey, which is very time-consuming and laborious. Therefore, in actual construction, only one or several locations are surveyed for each structure, and the number of surveys is changed according to the importance of the structure. However, generally, the properties of the ground have a complex structure composed of alluvial layers, diluvial layers, etc. Therefore, the formation composition may be different at adjacent penetration work locations, and complementary property surveys and high-density property surveys at intermediate positions are desired. In particular, when investigating the properties of the ground using the above-described excavation parameters at an intermediate position, the survey results will be greatly improved, so the demand is even greater.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a method for determining the properties of the ground that can more accurately grasp the properties of the entire ground.

Means for Solving the Problems

[0006] In determining the properties of the ground, conventionally, it was common to classify and determine the ground from an academic perspective of soil classification. However, in ground improvement, it is sufficient if the classification necessary for improvement can be made. Therefore, the means shown below was conceived based on such an idea.

[0007] (The means according to claim 1) When determining the properties of the ground extending in the vertical, horizontal, and depth directions, investigate the properties of the ground in the depth direction at a plurality of points in the vertical and horizontal directions respectively, then, at the investigation points where the above-mentioned investigations are carried out adjacent to each other, identify the ground that satisfies a predetermined condition respectively, and connect the identified grounds together, A method for determining the properties of the ground, characterized in that.

[0008] (The means according to claim 2) The connection of the identified grounds together is divided into two cases: when there are two or more layers of the identified ground at the other investigation point within the depth range of the identified ground at one investigation point, and other cases, The method for determining the properties of the ground according to claim 1.

[0009] (The means according to claim 3) The predetermined condition is any one or more of the moisture content of the ground, the hardness of the ground, and the classification of the ground. The method for determining the properties of the ground according to claim 1.

[0010] (The means according to claim 4) When determining the properties of the ground between adjacent investigation points, the ground is divided in the depth direction, the ratio of the specific ground within each division is calculated, and the properties of the ground are determined based on this calculated value. The ground property determination method according to claim 1.

Advantages of the Invention

[0011] According to the present invention, it becomes a ground property determination method capable of more accurately grasping the properties of the entire ground.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] Next, embodiments for carrying out the invention will be described. Note that this embodiment is an example of the present invention. The scope of the present invention is not limited to the scope of this embodiment.

[0014] In the method for determining the properties of the ground in this form, as shown in FIG. 1, the ground G extending in the vertical direction Y, the horizontal direction X, and the depth direction Z (see FIG. 2) is targeted. And in this method, the properties of the ground (continuous) in the depth direction Z are investigated at two or more than three locations in the vertical direction Y and the horizontal direction X respectively. As a method for this investigation, for example, in addition to the method of actually excavating and investigating such as the core boring, standard penetration test, dynamic penetration test, vane test, cone penetration test, etc. described above, various data are measured during boring, and these data are analyzed by a computer or the like. A ground strength measurement method, a soil hardness measurement method for a boring auger, a survey method using boring parameters such as an empasol, etc. can be adopted. In the figure, the points where boring, hole drilling, etc. are performed are indicated by the symbol P as survey points. Also, when ground improvement is performed without actually conducting a survey between these survey points P, the location where this improvement is performed is regarded as a pseudo point and is indicated by the symbol Q.

[0015] In determining the overall properties of the ground G, the ground that satisfies a predetermined condition at mutually adjacent survey points P is specified respectively, and these specified grounds are joined together and it is determined that the ground at the intermediate point (between them) is also a specific ground.

[0016] Here, the predetermined condition means a condition that becomes a factor during ground improvement. For example, if the injection amount of the solidifying material is changed according to the moisture content, the moisture content is the condition, and if the stirring speed is changed according to the hardness of the ground, the hardness can be the condition. Of course, for example, the classification of the ground such as soft rock, gravel, sand, silty sand, sandy silt, silt, clay, etc. can also be set as a predetermined condition (by the way, the boring speed becomes faster in this order). The main point is that it is sufficient if it is a factor that can determine whether the condition is satisfied or not (binary).

[0017] As a method for connecting specific ground, various methods can be considered, but preferably, the connection is made by comparing the depth position and thickness of the specific ground at one of the survey points P adjacent to each other with the ground composition at the other survey point. Hereinafter, more detailed specific examples will be described.

[0018] In this embodiment, first, prior to the above connection, as shown in FIG. 2, the survey point P closest to the outer edge L of the determination range (improvement range) is extracted. Then, it is assumed that the specific ground N constituting the ground G of this survey point P continues to the outer edge L. In the illustrated example, the ground determined by the reference numeral NL is shown.

[0019] Note that the specific ground N does not mean only a specific ground, and there may be a plurality of locations, and the above assumption is made for each of all the specific grounds constituting the survey point P.

[0020] Next, when connecting between the survey points P adjacent to each other, that is, when determining the specific ground, it is preferable to perform the operation according to the following procedure. First, as shown in FIG. 3(1), at the other survey point Pb, when there are two or more specific grounds within the depth range of the specific ground (indicated by the reference numeral N1) at one survey point Pa (in the drawing, the case where there are two locations is taken as an example and is indicated by the reference numerals N2 and N3), and the other cases, the above connection is made separately. Note that the case where there are two or more locations means that a plurality of specific grounds are located within the depth range of one specific ground, and the depth of each specific ground is based on, for example, the midpoint (intermediate point in the depth direction Z) depth.

[0021] And in the case where there are two or more locations, first, the uppermost depth position X1 and the lowermost depth position X2 are selected from the upper end depth positions and the lower end depth positions of the plurality of specific grounds N2, N3 at the other survey point Pb, and line segments L1, L2 are created toward the upper end depth position X3 and the lower end depth position X4 of the specific ground N1 at one survey point Pa.

[0022] Also, as shown in (2) of FIG. 3, a horizontal line L3 is created from the midpoint depth position X5 of another ground N4 sandwiched between the specific grounds N2 and N3 of the other survey point Pb toward one survey point Pa, and an intersection X6 is obtained on the specific ground N1 of one survey point Pa. Then, as shown in (3) of FIG. 3, the lines connecting this intersection X6 with the lower end depth position of the upper specific ground N2 and the upper end depth position of the lower specific ground N3 are defined as line segments L4 and L5, respectively.

[0023] Then, between the line segment L1 and the line segment L4 created above, and between the line segment L5 and the line segment L2, they are respectively determined to be the specific ground N. The same operation is performed for all specific grounds N.

[0024] Also, in the case of one survey point Pa that remains unprocessed (undetermined) above, that is, in the case other than when the specific ground N of the above one survey point Pa corresponds to two or more specific grounds N of the other survey point Pb (other cases), the following operations are performed.

[0025] First, as shown in (1) of FIG. 4, line segments are created from the midpoint depth of the specific ground N6 of one survey point Pa to the midpoint depths of all the specific grounds N7, N8, etc. of the other survey point Pb (the created line segments are exemplified as reference numerals L11 to L14, etc.).

[0026] Then, first, the line segments that overlap with the specific ground N determined above are removed from all the line segments (L11 to L14). Next, the shortest one among the removed line segments is selected (extracted). In the illustrated example, the line segment L11 is extracted. Once this extraction is done, the upper end depth position X13 of the specific ground N7 corresponding to the line segment L11 and the upper end depth position X11 of the specific ground N6 are connected by a line segment, and similarly, the lower end depth position X14 of the specific ground N7 and the lower end depth position X12 of the specific ground N6 are connected by a line segment. Then, between the line segments created above, they are determined to be the specific ground N. The same operation is performed for all specific grounds N.

[0027] For the specific ground N of one of the investigation points Pa that has not been processed above, perform the following operations. First, as shown in Figure 5, create a horizontal line L20 from the mid-depth position of the specific ground N9 of one of the investigation points Pa. Then, the point where this created horizontal line L20 intersects the stratum N20 other than the specific ground of the other investigation point Pb is defined as the intersection point X20. Then, connect this intersection point X20 with the upper-end depth position and the lower-end depth position of the specific ground N9 of one of the investigation points Pa respectively, and name the two created line segments L21 and L22. It is confirmed that these two line segments L21 and L22 do not intersect the already determined specific ground. After confirmation, determine the area between the two line segments L21 and L22 as the specific ground.

[0028] Also, as shown in Figure 6, for the specific ground N11 of one of the investigation points Pa that has not been processed above, create two line segments from the upper-end depth position and the lower-end depth position to the upper-end depth positions and the lower-end depth positions of the specific grounds N12 and N13 of the other investigation point Pb respectively. For these two line segments, it is confirmed that neither of them intersects the specific ground created above. If it is confirmed that they do not intersect, extract the two line segments with the shortest distance between them. Then, determine the area between these two line segments as the specific ground.

[0029] The above determination can be used as it is, but it is also preferable to use it after classification as follows. That is, when determining the properties of the ground between adjacent investigation points, first divide the ground in the depth direction. For example, divide the ground at 1 - 3m. Then, calculate the ratio of the specific ground determined above within each division, and determine the properties of the ground based on this calculated value. For example, when the ratio of the specific ground is 0 - 20%, it is classified as division 1, when it exceeds 20% - 40%, it is classified as division 2, and when it exceeds 40% - 100%, it is classified as division 3. And when improving the pseudo point Q, determine the improvement method based on this classification (for example, divisions 1 - 3).

[0030] It is preferable to digitize all of the above processes so that they can be output to a monitor, chart paper, etc. as appropriate.

Industrial Applicability

[0031] The present invention can be used as a method for determining the properties of the ground.

Explanation of Signs

[0032] N, N1, N2, N3, N4, N6, N7, N8, N9, N11, N12, N13, N20, NL... Specific ground L1, L2, L3, L4, L5, L11, L12, L13, L14, L20, L21, L22... Line segments G... Ground P... Investigation point Pa... One investigation point Pb... The other investigation point Q... Pseudo point X... Horizontal direction Y... Vertical direction Z... Depth direction

Claims

1. When determining the properties of the ground extending in the vertical, horizontal, and depth directions, a plurality of investigations are respectively conducted on the properties of the ground in the vertical and horizontal directions regarding the depth direction, then, at the investigation points where the above-mentioned investigations are adjacent to each other, the ground satisfying a predetermined condition is respectively specified, and these specified grounds are joined together, A method for determining the properties of the ground, characterized by the above.

2. The joining together of the above-mentioned specified grounds is performed separately depending on whether there are two or more layers of the specified ground at the other investigation point within the depth range of the specified ground at one investigation point and other cases, The method for determining the properties of the ground according to Claim 1.

3. The above-mentioned predetermined condition is any one or more of the moisture content of the ground, the hardness of the ground, and the classification of the ground, The method for determining the properties of the ground according to Claim 1.

4. When determining the properties of the ground between investigation points adjacent to each other, the ground is divided in the depth direction, the ratio of the above-mentioned specified ground within each division is calculated, and the properties of the ground are determined based on this calculated value, The method for determining the properties of the ground according to Claim 1.

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