A construction method for a stratum adjacent to a horizontal foundation surface of a nuclear island

Abstract

The application discloses a construction method of a rock layer adjacent to a horizontal foundation plane of a nuclear island, and specifically comprises the following steps: test blasting, determination of a standard blasting crater radius; standard blasting crater optimization combination; calculation of bench blasting hole row spacing; analysis of a ground shape after bench blasting; calculation of a terrain volume after bench blasting; bench blasting crater combination with a structural group; bench blasting hole row spacing selection; selection of a non-blasting construction thickness of a protective layer; and non-blasting layer engineering quantity calculation. The application adopts standard blasting crater combination, analyzes a blasting crater circular arrangement combination rule, finds out a relationship between the blasting hole row spacing and a left terrain after blasting, analyzes advantages and disadvantages of a blasting protective layer and a non-blasting protective layer, can adapt to extreme environmental conditions of an unfavorable blasting construction, avoids a blasting fly rock risk, and can protect the nuclear island foundation plane.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant nuclear island blasting technology construction, and in particular to a construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island. Background Technology

[0002] Based on nuclear power plant safety considerations, it is required to protect the integrity and stability of the rock strata of the nuclear island foundation, and to meet the quality and technical requirements that the nuclear island foundation strata must not be under-excavated and over-excavated by no more than 20-40 cm. The common approach is to reserve a protective layer of a certain thickness adjacent to the designed foundation surface of the nuclear island, and then implement specific measures within the protective layer to reduce the peak effect of explosives on the foundation rock strata before blasting. There are four methods for the single-stage blasting of the protective layer: 1) a combination of horizontal pre-blasting and horizontal hole bench blasting; 2) a combination of horizontal pre-blasting and vertical shallow hole bench blasting; 3) a combination of horizontal smooth blasting and horizontal shallow hole bench blasting; and 4) bench blasting with flexible or composite cushioning or air columns at the bottom of the hole. The first three single-stage blasting methods are rarely used due to limitations in nuclear island operating space and drilling equipment. Nuclear island protective layer blasting construction mostly adopts a method with vertical flexible or composite cushioning or air columns at the bottom of the hole, large radial coupling of the charge, small hole spacing, and small bench blasting. After blasting, the remaining bottom is then mechanically leveled using a hydraulic breaker.

[0003] Practice has shown that the protective layer blasting method has the following main disadvantages: First, due to the dense blasting holes and small steps, the cost is higher than that of ordinary bench blasting. Second, the use of flexible cushions or air columns at the bottom of the holes makes construction cumbersome and increases blasting costs. Third, although the flexible cushions or air columns at the bottom of the holes can reduce the blasting effect of explosives on the foundation rock layer, there is still some irreversible damage to the foundation rock layer. Fourth, the construction process of the protective layer blasting method involves discontinuity in drilling, blasting, and material discharge. The detonation time window is fixed, limiting the flexibility of the operation time. In addition, the amount of explosives per hole and the total amount of explosives in a single blast must be strictly controlled for each blast, and the blasting scale is relatively small, all of which result in low construction efficiency. Fifth, from the perspective of blasting safety, blasting is not allowed at night, and the time for rushing to complete the work at night is limited. Sixth, due to the sequential construction of adjacent nuclear islands, civil engineering and earthwork are carried out simultaneously. There are many construction units and workers around the blasting point, the environment is complex, blasting warning is very difficult, and the risk of flyrock from small bench blasting is high, posing a great safety hazard.

[0004] Most of the construction experience of the bench blasting method using flexible or composite cushions or air columns at the bottom of the hole in nuclear island blasting construction focuses on the flexible cushions or air columns to reduce the destructive effect of explosives on the base plate. However, little attention is paid to the relationship between the hole spacing and the blasting funnel in the bench blasting of the protective layer, the shape of the blasting funnel residue, the measurement of the engineering work left by the funnel residue, and the relationship with subsequent construction procedures.

[0005] Regarding the cost of the protective layer for earthwork blasting construction on the nuclear island, a preliminary assessment of the post-blast ground shape and its volume is also required. Summary of the Invention

[0006] The purpose of this invention is to overcome the deficiencies in the prior art and provide a construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island. It adopts a standard blasting funnel combination, analyzes the circular arrangement combination law of the blasting funnels, finds out the relationship between the spacing of the blasting holes and the terrain left after blasting, analyzes the advantages and disadvantages of the blasting protective layer and the non-blasting protective layer, and can adapt to extreme environmental conditions that are not conducive to blasting construction, avoid the risk of blasting fly rocks, and at the same time protect the foundation surface of the nuclear island.

[0007] The objective of this invention is achieved as follows: a construction method for rock strata adjacent to the horizontal foundation surface of a nuclear island, comprising the following steps:

[0008] (1) Conduct test blasting to determine the radius of the standard blasting funnel;

[0009] (2) Optimized combination of standard blasting funnels;

[0010] (3) Calculate the spacing of the blasting holes in the steps;

[0011] (4) Analyze the ground shape after the bench blasting;

[0012] (5) Calculation of terrain volume after bench blasting;

[0013] (6) Step-blasting funnel combination isomorphic group;

[0014] (7) Selection of the spacing between the blasting holes in the steps;

[0015] (8) Selection of protective layer thickness for non-blasting construction;

[0016] (9) Calculation of the quantity of non-blasting layer.

[0017] Further, step (1) specifically includes: selecting the type and density of explosives based on geological and lithological conditions, selecting the borehole diameter based on equipment resources, and determining the standard blasting funnel radius through a blasting funnel test.

[0018] Further, step (2) specifically includes: setting the blasting rock as a homogeneous and isomorphic body, assuming the blasting funnel is a standard blasting funnel, according to the Livingston blasting funnel principle, in order to blast the maximum amount of explosive, the energy should be evenly distributed, the blasting funnel circles should not overlap or have minimal overlap, and since there should be no raw rock material between the blasting funnel circles, the blasting funnel circles must intersect. The blasting layout forms that meet the requirements of minimal overlap and intersection of blasting funnel circles include quincunx-shaped holes and rectangular holes. The quincunx-shaped holes have three adjacent funnel circles intersecting at one point, and six blasting funnel circles are evenly distributed around the perimeter of each central blasting funnel circle, with the centers of each of the three adjacent funnel circles forming an equilateral triangle; the rectangular holes have four adjacent funnel circles intersecting at one point, and eight blasting funnel circles are evenly distributed around the perimeter of the central blasting funnel circle, with the centers of each of the four adjacent funnel circles forming a square.

[0019] Further, step (3) specifically includes: setting the radius of the standard blasting funnel circle as r, determining the blasting hole spacing parameters, and in the three-lobed quincunx-shaped hole arrangement, the hole spacing is... In the four-petaled rectangular blasting hole, the hole spacing is...

[0020] Furthermore, step (4) specifically includes: in order to clearly understand the shape of the ground after blasting, first explore the curve of the intersection of the blasting funnels and the volume of the overlapping blasting funnels;

[0021] In the coordinate system shown in the diagram where the blasting funnel intersects the plane, let h be the height of the cone and r be the radius of the standard blasting funnel circle, then we have:

[0022] The equation of the cone is: x 2 +y 2 =(hz) 2 r 2 / h 2 (1) Let the distance between a plane and the central axis of the blasting funnel be c, then we have y = c (a constant, and 0 < c < r).

[0023]

[0024] The equation of the curve intercepted by the plane and the cone is:

[0025] (hz) 2 r 2 / (c 2 h 2 )-x 2 / c 2 =1 (discard half of the curve) (3), the curves intersecting the blasting funnel surfaces are hyperbolas;

[0026] When the blasting is done in a three-petaled plum blossom-shaped borehole configuration, the remaining rock mass between the blasting funnels is a three-curved, three-faced, pointed solid composed of three hyperbolic ridges and three conical surfaces. When the blasting is done in a four-petaled rectangular borehole configuration, the remaining rock mass between the blasting funnels is a four-curved, four-faced, pointed solid composed of four hyperbolic ridges and four conical surfaces. In the pointed solids composed of three-curved ridges and three-faced surfaces and four-curved ridges and four-faced surfaces, all the ridges are hyperbolic, and all the surfaces are conical. After the blasting, the blasting funnels and pointed solids are interspersed and distributed symmetrically. Through the analysis of the post-blast topographic cross-section, the highest point of the blasting remaining rock mass is located at the centroid of the figure formed by the centers of the blasting funnel circles. The highest distance is the radius r of the blasting funnel circle.

[0027] Furthermore, step (5) specifically includes: the volume of rock left after the step blast refers to the volume of rock above the bottom plane of the blasting funnel that has not been broken by the explosive, which is used to calculate the project cost;

[0028] The real axis of the hyperbola lies on the z-axis. Let S be the area enclosed by the hyperbola and the XOY surface. The area S of the hyperboloid is:

[0029]

[0030] Let c = y, then we have

[0031]

[0032] Let v be the volume of the small piece cut by the plane from the blasting funnel cone, then we have

[0033]

[0034] The volume of the cone cut off by the plane y = c is: The volume cut off is:

[0035]

[0036] Further, step (6) specifically includes: in order to rapidly reduce the height of the post-blasting residual rock, the distance between the blasting funnel circles must be reduced. Different residual rock heights correspond to different blasting funnel combinations. This correspondence is one-to-one. Many different blasting funnel combinations form a group. The group has the same structure. This group is called the blasting funnel hole arrangement combination isomorphic group. The plum blossom-shaped hole arrangement is an equilateral triangle. This group is called the equilateral triangle blasting funnel hole arrangement combination isomorphic group. The rectangular hole arrangement is a square. This group is called the square blasting funnel hole arrangement combination isomorphic group. The blasting funnel hole arrangement combination isomorphic group has the following properties: in the equilateral triangle blasting funnel hole arrangement combination group or the square blasting funnel hole arrangement combination group, the one-dimensional measure (length, width, height) related to the blasting residual rock also changes proportionally to k. The two-dimensional measure (area) related to the blasting residual rock changes proportionally to k. 2 Proportional changes, three-dimensional measurements (volume) related to blasting-residual rock quality, proportional to k 3 change.

[0037] Further, step (7) specifically includes: utilizing the properties of the isomorphic group of blasting funnels and a rectangular hole arrangement in either the equilateral triangular blasting hole arrangement group or the square blasting hole arrangement group, and freely selecting the required rectangular blasting hole arrangement based on this known form.

[0038] Further, step (8) specifically includes: using the selected mechanical equipment to perform on-site rock removal tests, and determining the thickness of the non-blasting construction rock layer based on the test results.

[0039] Further, step (9) specifically includes: the non-blasting engineering quantity, namely the hydraulic breaker chiseling engineering quantity, mainly includes the protective layer engineering quantity and the step blasting residue. The protective layer engineering quantity is the product of the protective layer thickness and the construction area. After the hole spacing is selected, the volume of the rock mass remaining in the step blasting funnel can be calculated by using the volume formula (7) and the combination calculation of prism volume, cone volume, etc.

[0040] In operation, this invention optimizes the combination of standard blasting funnels to analyze the distribution patterns of the ground medium's height, shape, and volume after blasting, identifying the relationship between the blast hole spacing and the post-blast ground medium shape. Based on this relationship, and according to the client's requirements and blasting environment, parameters such as the blast hole spacing are established to control the post-blast ground medium shape, guiding construction. Furthermore, by using a volume formula relating blast hole spacing to the post-blast ground shape, the cost of the protective layer for non-blasting construction is predicted. This improves the understanding of the impact of blasting funnels on the post-blast terrain, clarifies the causes of the post-blast terrain, and clarifies the method for measuring the post-blast ground shape, facilitating the establishment of earthwork cost contracts between the client and contractor and reducing disputes over contract pricing. For bench blasting above the protective layer, optimizing the hole spacing using this invention can reduce the construction cost of bench blasting.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: After changing the protective layer blasting construction to non-blasting construction, the non-blasting protective layer is a thin layer. The step blasting above the thin non-blasting protective layer is carried out with specially optimized hole spacing to reduce the height of the blasting residue and reduce the workload of the non-blasting layer. The use of non-blasting construction layer is conducive to controlling the quality of the foundation surface, reducing the risk of over-excavation of the foundation surface bottom plate, omitting the flexible cushion layer or air column measures at the bottom of the step blasting hole, and also eliminating the risk of flyrock from the protective layer blasting, so as to give full play to the role of the protective layer. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a three-petaled plum blossom-shaped blasting hole.

[0043] Figure 2 This is a schematic diagram of a rectangular blasting hole for a four-petal flower pattern.

[0044] Figure 3 This is a schematic diagram showing the intersection of the blasting funnel and the plane.

[0045] Figure 4 This is a schematic diagram comparing blasting and non-blasting methods for constructing a protective layer.

[0046] Among them, 1 is the protective blasting surface, 2 is the filling section, 3 is the emulsion explosive, 4 is the buffer block, 5 is the stepped blasting surface, 6 is the non-blasting protective layer, 7 is the baseline, and 8 is the allowable ultra-deep line. Detailed Implementation

[0047] like Figures 1-4 The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island is shown below:

[0048] (1) Test blasting to determine the standard blasting funnel radius: Select the type and density of explosives based on geological and lithological conditions, select the borehole diameter according to equipment resources, and determine the standard blasting funnel radius through blasting funnel test.

[0049] (2) Optimization of standard blasting funnels: The blasting rock is assumed to be a homogeneous and in-phase body. Assuming the blasting funnel is a standard blasting funnel, according to the Livingston blasting funnel principle, in order to blast the maximum amount of explosive, the energy should be evenly distributed. The blasting funnel circles should not overlap or have minimal overlap. Since no raw rock material can be left between the blasting funnel circles, the blasting funnel circles must intersect. The blasting layout forms that meet the requirements of minimal overlap and intersection of blasting funnel circles include quincunx hole layout and rectangular hole layout. In the quincunx hole layout, three adjacent funnel circles intersect at one point, and six blasting funnel circles are evenly distributed around the perimeter of each central blasting funnel circle. The centers of each three adjacent funnel circles form an equilateral triangle. In the rectangular hole layout, four adjacent funnel circles intersect at one point, and eight blasting funnel circles are evenly distributed around the perimeter of the central blasting funnel circle. The centers of each four adjacent funnel circles form a square.

[0050] (3) Calculate the spacing of the blasting holes in the bench: Set the radius of the standard blasting funnel circle as r, determine the spacing parameters of the blasting holes, and in the three-lobed quincunx pattern, the hole spacing is... In the four-petaled rectangular blasting hole, the hole spacing is...

[0051] (4) Analyze the ground shape after the step blast: In order to clearly understand the ground shape after the blast, we first discuss the curve of the intersection of the blast funnels and the volume of the overlapping blast funnels.

[0052] In the coordinate system shown in the diagram where the blasting funnel intersects the plane, let h be the height of the cone and r be the radius of the standard blasting funnel circle, then we have:

[0053] The equation of the cone is: x 2 +y 2 =(hz) 2 r 2 / h 2 (1) Let the distance between a plane and the central axis of the blasting funnel be c, then we have y = c (a constant, and 0 < c < r).

[0054]

[0055] The equation of the curve intercepted by the plane and the cone is:

[0056] (hz) 2 r 2 / (c 2 h 2 )-x 2 / c 2 =1 (discard half of the curve) (3), the curves intersecting the blasting funnel surfaces are hyperbolas;

[0057] When the blasting is done in a three-petaled plum blossom-shaped borehole configuration, the remaining rock mass between the blasting funnels is a three-curved, three-faced, pointed solid composed of three hyperbolic ridges and three conical surfaces. When the blasting is done in a four-petaled rectangular borehole configuration, the remaining rock mass between the blasting funnels is a four-curved, four-faced, pointed solid composed of four hyperbolic ridges and four conical surfaces. In the pointed solids composed of three-curved ridges and three-faced surfaces and four-curved ridges and four-faced surfaces, all the ridges are hyperbolic, and all the surfaces are conical. After the blasting, the blasting funnels and pointed solids are interspersed and distributed symmetrically. Through the analysis of the post-blast topographic cross-section, the highest point of the blasting remaining rock mass is located at the centroid of the figure formed by the centers of the blasting funnel circles. The highest distance is the radius r of the blasting funnel circle.

[0058] (5) Calculation of terrain volume after bench blasting: The volume of blasted rock remaining after bench blasting refers to the volume of rock above the bottom plane of the blasting funnel that has not been broken by the explosive, and is used to calculate the project cost;

[0059] The real axis of the hyperbola lies on the z-axis. Let S be the area enclosed by the hyperbola and the XOY surface. The area S of the hyperboloid is:

[0060]

[0061] Let c = y, then we have

[0062]

[0063] Let v be the volume of the small piece cut by the plane from the blasting funnel cone, then we have

[0064]

[0065] The volume of the cone cut off by the plane y = c is: The volume cut off is:

[0066]

[0067] When the blasting funnel is a standard funnel, h = r, let h = r = 1 unit, and let the volume of the standard blasting funnel be V. 标 Then, V 标 =π / 3≈1.0472;

[0068] but

[0069] when At that time, v≈0.0047, v / V 标 ≈0.45% (9),

[0070] when At that time, v≈0.0252, v / V 标 ≈2.41% (10),

[0071] when At that time, v≈0.1153, v / V 标 ≈11.01% (11),

[0072] like Figure 1 As shown in the schematic diagram of the three-lobed plum blossom-shaped blasting hole arrangement, calculate the volume of the medium remaining after the blast in the equilateral triangle, assuming the radius of the blasting funnel is 1 unit.

[0073] Volume of a triangular prism:

[0074] The volume of the remaining rock is: 1.2990-0.5×1×3.1416×1×1 / 3+3×0.0047≈0.7895. In the three-lobed plum blossom-shaped hole arrangement, the volume of each blasting funnel is approximately 0.2631.

[0075] like Figure 2 As shown in the schematic diagram of the four-petaled rectangular blasting hole layout, calculate the volume of the rock residue left after the square blast and the volume of the quadrangular prism:

[0076] The volume of the remaining rock is: 2 - 1 × 1 × 3.1416 × 1 × 1 / 3 + 4 × 0.0252 ≈ 1.0536. In the four-petal rectangular blasting hole, the volume of the remaining rock in each blasting funnel accounts for about 0.2634.

[0077] (6) Step-type blasting funnel combination isomorphic group: In order to rapidly reduce the height of the post-blasting residual rock, the distance between the blasting funnel circles must be reduced. Different residual rock heights correspond to different blasting funnel combinations. This correspondence is one-to-one. Many different blasting funnel combinations form a group. The group has the same structure. This group is called the blasting funnel hole arrangement combination isomorphic group. The quincunx hole arrangement is an equilateral triangle. This group is called the equilateral triangle blasting funnel hole arrangement combination isomorphic group. The rectangular hole arrangement is a square. This group is called the square blasting funnel hole arrangement combination isomorphic group. The blasting funnel hole arrangement combination isomorphic group has the following properties: In the equilateral triangle blasting funnel hole arrangement combination group or the square blasting funnel hole arrangement combination group, the one-dimensional measure (length, width, height) related to the blasting residual rock changes proportionally to the change in one blasting hole arrangement form from one blasting hole arrangement form to another. The two-dimensional measure (area) related to the blasting residual rock changes proportionally to the change in one blasting hole arrangement form. 2 Proportional changes, three-dimensional measurements (volume) related to blasting-residual rock quality, proportional to k 3 change.

[0078] (7) Selection of the spacing of the blasting holes in the steps: Based on the properties of the isomorphic group of the blasting funnel combination and the rectangular pattern of the hole arrangement in the equilateral triangle blasting hole arrangement group or the square blasting hole arrangement group, the required rectangular pattern of the blasting hole arrangement can be freely selected according to this known form.

[0079] The protective layer blasting requires a residual medium height of 0.5 meters. Assuming a blasting funnel radius of 1.5 meters, two blasting hole layouts are used: equilateral triangular and square. The equilateral triangular blasting hole layout and hole spacing have already been given. Square blasting cloth hole type, hole spacing is The highest point of the corresponding post-explosion residual medium is r. Since 1.5 m / 0.5 m = 3, the hole spacing for the equilateral triangular blasting layout is... Approximately 0.87 meters: 0.75 meters; square blasting hole layout, hole spacing is... Approximately 0.71 meters: 0.71 meters.

[0080] (8) Selection of the thickness of the protective layer for non-blasting construction: Using the selected mechanical equipment, the rock is removed on site through a test, and the thickness of the rock layer for non-blasting construction is determined based on the test results. Figure 4 This diagram illustrates the comparison between blasting and non-blasting construction methods for protective layers. In blasting construction, the protective layer consists of, from top to bottom, a protective layer blasting face 1, a filling section 2, emulsion explosive 3, and a buffer block 4. The buffer block 4 is either a flexible cushion or an air column. In non-blasting construction, the layers consist of, from top to bottom, a stepped blasting face 5, a filling section 2, emulsion explosive 3, a non-blasting protective layer 6, a foundation line 7, and an allowable over-depth line 8. Using non-blasting construction layers allows for better control of the foundation surface quality, reduces the risk of over-excavation of the foundation slab, eliminates the need for stepped blasting flexible cushions or air columns, avoids the risk of flying rocks during leveling blasting, and fully utilizes the protective layer's function.

[0081] (9) Calculation of non-blasting layer engineering quantity: Non-blasting engineering quantity, namely the hydraulic breaker hammer chiseling engineering quantity, mainly includes the protective layer engineering quantity and the part left by the step blasting. The protective layer engineering quantity is the product of the protective layer thickness and the construction area. After the hole spacing is selected, the volume of the rock material left by the step blasting funnel can be calculated by using the volume formula (7) and the combination calculation of prism volume, cone volume, etc.

[0082] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A construction method for rock strata adjacent to the horizontal foundation surface of a nuclear island, characterized in that, Includes the following steps: (1) Conduct test blasting to determine the radius of the standard blasting funnel; (2) Determine the optimal combination of standard blasting hoppers; (3) Calculate the spacing of the blasting holes in the steps; (4) Analyze the ground shape after the bench blasting; (5) Calculation of terrain volume after bench blasting; (6) Determine the isomorphic group of the stepped blasting funnel combination; (7) Selection of spacing between blasting holes in steps; (8) Selection of protective layer thickness for non-blasting construction; (9) Calculation of the quantity of non-blasting layer engineering; Step (2) specifically includes: setting the blasting rock as a homogeneous phase body, the blasting funnel as a standard blasting funnel, according to the Livingston blasting funnel principle, in order to blast out the maximum amount of explosive, the energy should be evenly distributed, the blasting funnel circles should not overlap or have minimal overlap, and since there should be no raw rock material between the blasting funnel circles, the blasting funnel circles must intersect. The blasting hole layout forms that meet the requirements of minimal overlap and intersection of blasting funnel circles include quincunx hole layout and rectangular hole layout. The quincunx hole layout has three adjacent funnel circles intersecting at one point, and six blasting funnel circles are evenly distributed around the perimeter of each central blasting funnel circle. The centers of each of the three adjacent funnel circles form an equilateral triangle. The rectangular hole layout has four adjacent funnel circles intersecting at one point, and eight blasting funnel circles are evenly distributed around the perimeter of the central blasting funnel circle. The centers of each of the four adjacent funnel circles form a square. Step (6) specifically includes: In order to rapidly reduce the height of the residual rock after the blast, the distance between the blasting funnel circles must be reduced. Different residual rock heights correspond to different blasting funnel combinations. This correspondence is one-to-one. Many different blasting funnel combinations form a group. The group has the same structure. This group is called the blasting funnel hole arrangement combination isomorphic group. The plum blossom-shaped hole arrangement is an equilateral triangle. This group is called the equilateral triangle blasting funnel hole arrangement combination isomorphic group. The rectangular hole arrangement is a square. This group is called the square blasting funnel hole arrangement combination isomorphic group. The blasting funnel hole arrangement combination isomorphic group has the following properties: In the equilateral triangle blasting funnel hole arrangement combination group or the square blasting funnel hole arrangement combination group, the blasting hole arrangement form changes proportionally k from one blasting hole arrangement form to another. The one-dimensional measure related to the blasting residual rock, namely the length, width, and height, also changes proportionally k. The two-dimensional measure related to the blasting residual rock, namely the area, changes proportionally k. 2 Proportional variation, a three-dimensional measure related to the blasting-residual rock, i.e., volume proportional to k. 3 change; Step (7) specifically includes: using the properties of the isomorphic group of blasting funnels, combined with the known hole spacing of the equilateral triangle or square blasting hole group, to select the required blasting hole spacing.

2. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 1, characterized in that: The specific steps (1) include: selecting the type and density parameters of explosives based on geological and lithological conditions, selecting the borehole diameter based on equipment resources, and determining the standard blasting funnel radius through blasting funnel tests.

3. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 2, characterized in that: Step (3) specifically includes: setting the radius of the standard blasting funnel circle as r, determining the blasting hole spacing parameters, and in the three-lobed plum blossom-shaped hole arrangement, the hole spacing is... r: r, in a four-petaled rectangular blasting hole, the hole spacing is... r r.

4. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 3, characterized in that: The specific steps (4) include: in order to clearly understand the shape of the ground after blasting, first explore the curve of the intersection of the blasting funnels and the volume of the overlapping blasting funnels; Let h be the height of the cone, and r be the radius of the standard blasting hopper circle. Then the equation of the cone is: x 2 +y 2 =(h-z) 2 r 2 / h 2 (1), Let the distance between a plane and the central axis of the blasting hopper be c. Then we have y = c, where c is a constant, and 0 < c < r, z h= (2), The equation of the curve intercepted by the plane and the cone is: (h-z) 2 r 2 / (c 2 h 2 )-x 2 / c 2 =1 (3), Formula (3) determines that the intersection curve of the blasting hopper surfaces is a hyperbola; Therefore, when the blasting is done in a three-petaled plum blossom-shaped hole arrangement, the remaining rock mass between the blasting funnels is a three-curved, three-faced, pointed solid composed of three hyperbolic ridges and three conical surfaces; when the blasting is done in a four-petaled rectangular hole arrangement, the remaining rock mass between the blasting funnels is a four-curved, four-faced, pointed solid composed of four hyperbolic ridges and four conical surfaces; in the pointed solid composed of three-curved ridges and three-faced surfaces and the pointed solid composed of four-curved ridges and four-faced surfaces, all the ridges are hyperbolic and all the surfaces are conical; after the blasting, the blasting funnels and pointed solids are interspersed and distributed symmetrically; through the analysis of the post-blast topographic cross section, the highest point of the blasting remaining rock mass is located at the centroid of the figure formed by the centers of the blasting funnel circles, and the highest distance is the radius r of the blasting funnel circle.

5. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 4, characterized in that: The specific steps (5) include: the volume of rock left after the step blast refers to the volume of rock above the bottom plane of the blasting funnel that has not been broken by the explosive, which is used to calculate the project cost; The real axis of the hyperbola lies on the z-axis. Let S be the area enclosed by the hyperbola and the XOY surface. The area S of the hyperboloid is: S=2 dx =h + ln( ) lnc (4), Let c = y, then we have S=h + ln( ) lny (5), let v be the volume of the small piece cut by the plane from the blasting funnel cone, then we have v= of = you = dy+ dy dy (6), then the volume of the cone cut off by the plane y=c is: v= of = you = dy+ of of = arcsin + ln lnc (7)。 6. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 5, characterized in that: The specific steps (8) include: using the selected mechanical equipment to perform on-site rock removal tests, and determining the thickness of the non-blasting construction rock layer based on the test results.

7. The construction method for the rock strata adjacent to the horizontal foundation surface of the nuclear island according to claim 6, characterized in that: The specific steps (9) include: the non-blasting layer engineering quantity, namely the hydraulic breaker chiseling engineering quantity, mainly includes the protective layer engineering quantity and the step blasting residue. The protective layer engineering quantity is the product of the protective layer thickness and the construction area. After the hole spacing is selected, the volume of the rock mass remaining in the step blasting funnel is calculated by using the volume formula (7) and the combination of prism volume and cone volume.

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