Mountainous area power transmission line tower footing drilling splitting rock breaking hole distance determining method

Abstract

A mountainous area power transmission line tower footing drilling splitting rock breaking hole pitch determination method comprises the following steps: establishing a mathematical model considering the coupling influence of multiple factors such as pile hole geometric parameters, lithology difference and equipment performance, quantifying the engineering price, the construction time and the function relationship between environment vibration response and the hole pitch, and establishing a multi-target weighted decision model; and optimal pitch determination under different construction conditions and engineering targets is realized. According to the method, the coupling influence of multiple factors such as pile hole geometric parameters, lithology differences and equipment performance is comprehensively considered, the multi-target weighted decision model is established through the weight distribution method to quantify the main target of the engineering, the optimal hole distance under different construction conditions and engineering targets is determined, the rock breaking efficiency is improved, the engineering price is reduced, and the construction safety is ensured.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering technology and relates to a method for determining the spacing of boreholes for rock splitting and breaking in mountainous areas for power transmission line tower foundations. It is applicable to the construction of boreholes for rock splitting and breaking in mountainous areas for power transmission lines. Background Technology

[0002] Drilling and rock-splitting technology is an important construction method for excavating power transmission line tower foundations in mountainous areas. This technology relies on a modular pneumatic drilling rig to drill a series of closely spaced, non-connected holes around the pile. Then, a rock splitter is used to apply force, fracturing the rock mass between the holes and creating a connection between them, ultimately forming a controllable rock-breaking surface. This technology has advantages such as requiring no water, high construction safety, and strong adaptability, making it particularly suitable for power transmission line tower foundation excavation projects in mountainous areas.

[0003] In drilling and rock-breaking operations, the hole spacing is a core parameter affecting both rock-breaking efficiency and construction safety. An excessively large hole spacing can lead to poor rock-breaking performance, significant vibration impact on the surrounding environment, and potential safety hazards; conversely, an excessively small hole spacing can cause interference between holes, increase project costs, and reduce construction efficiency. Therefore, a reasonable hole spacing is crucial not only for rock-breaking performance and project cost but also for construction safety and environmental disturbance control.

[0004] However, existing drilling and rock-breaking technologies still have the following technical problems in determining the hole spacing: (1) Existing technologies mostly rely on construction experience or analogy to determine the hole spacing, failing to systematically consider the coupled effects of multiple factors such as pile hole geometry parameters, rock type differences and equipment performance. This results in unclear quantitative relationships between project price, construction time and environmental vibration response and hole spacing, and uncertainty in construction results. (2) Existing methods cannot quantify the weight allocation of the main project objectives (price, construction period, environmental vibration response), make it difficult to clarify the importance of different objectives, and lack the ability to flexibly adjust under different project objectives; (3) Existing methods cannot calculate the optimal hole spacing based on construction conditions and engineering objectives, lack multi-objective coordination and control capabilities, and are difficult to meet the refined design requirements under different construction conditions and engineering objectives. Summary of the Invention

[0005] To overcome the problems of existing technologies failing to comprehensively consider the coupled effects of multiple factors, being unable to perform multi-objective weighted decision-making, and lacking a method for determining the optimal hole spacing, this invention provides a method for determining the hole spacing for drilling and rock-breaking in mountainous transmission line tower foundations. This method comprehensively considers the coupled effects of multiple factors such as pile hole geometric parameters, lithological differences, and equipment performance. By establishing a multi-objective weighted decision-making model through a weight allocation method, it quantifies the main engineering objectives, determines the optimal hole spacing under different construction conditions and engineering objectives, improves rock-breaking efficiency, reduces engineering costs, and ensures construction safety.

[0006] The technical solution adopted by this invention to solve its technical problem is: A method for determining the spacing of boreholes for rock splitting and breaking in mountainous areas for transmission line tower foundations is proposed. This method establishes a mathematical model that considers the coupled effects of multiple factors such as pile hole geometry parameters, lithological differences, and equipment performance. It quantifies the functional relationship between project price, construction time, environmental vibration response, and borehole spacing, and establishes a multi-objective weighted decision-making model to determine the optimal borehole spacing under different construction conditions and project objectives.

[0007] Furthermore, the method includes the following steps: 1) Establish a single borehole price model that considers the impact of rock strength on energy consumption and drill bit wear; the functional relationship is: ; in, Price per linear meter of borehole, unit: yuan / m; This is the reference drilling price per linear meter for a single hole, in yuan / m; For reference rock strength, unit: MPa; The target rock strength, in MPa; This refers to the drilling resistance index; 2) The drilling resistance index is determined by the hardness of the drill bit material; the functional relationship is: ; in, Brinell hardness of drill bit material, unit: N / mm 2 ; Brinell hardness of rock, unit: N / mm 2 ; This is the drill tooth coefficient, determined based on the number of drill teeth, with a value ranging from 0.6 to 1.2. 3) Establish a single-stage splitting price model that considers the coupled effects of hole spacing, rock strength, equipment transportation costs, and rock splitter performance. The functional relationship is as follows: ; in, Price per splitting operation, unit: yuan / operation; This is a reference price for a single splitting operation, in yuan per operation. The shipping cost for a single splitting operation is in yuan per operation. Hole spacing, unit: mm; Reference hole spacing, unit: mm; The maximum splitting force of the reference splitter is expressed in kN. The maximum splitting force of the target engineering rock splitter, in kN; For reference, the mass of the splitter is expressed in kg. The target engineering splitter mass, unit: kg; 4) Based on hole spacing , radius of splitting hole and pile diameter Determine the number of boreholes Calculate the number of boreholes; the functional relationship is: ; 5) Determined by the number of boreholes and pile depth and the effective depth of a single split Calculate the number of splits The functional relationship is: ; 6) Establish a single-pile rock-breaking price model that considers the influence of pile hole geometry parameters, drilling price, number of boreholes, splitting price, and number of splitting operations; the functional relationship is: ; in, Price for single-pile rock breaking, unit: 10,000 yuan.

[0008] Furthermore, the method includes the following steps: 7) Establish a single-pile rock breaking time model considering the effects of hole spacing, rock strength, and the maximum splitting force of the rock splitter; the functional relationship is: ; in, The time for a single pile to break rock is expressed in days (d). The reference time for rock breaking per meter is expressed in d / m. The hole spacing time influence coefficient is determined by the ratio of hole spacing to split hole radius, and its value ranges from 0.005 to 0.015. The lithological time influence coefficient, determined by rock strength, ranges from 0.03 to 0.08. The splitting force time influence coefficient is determined by the equipment performance, and its value ranges from 0.005 to 0.015.

[0009] Furthermore, the method includes the following steps: 8) Establish a per-meter environmental vibration response model for a single borehole, considering the influence of rock strength on the cumulative environmental vibration energy of the drilling operation. The functional relationship is as follows: ; in, The cumulative environmental vibration energy per meter of a single borehole, in J / m; For reference, the cumulative environmental vibration energy per linear meter of a single borehole (unit: J / m). The coefficient representing the influence of lithology on borehole environment vibration; 9) Determine the influence coefficient of lithology on borehole environment vibration by using rock density; the functional relationship is:

[0010] in, For reference rock density, unit: kg / m³ 3 ; The target engineering rock density, unit: kg / m³ 3 ; 10) Establish a single-stage splitting environmental vibration response model that considers the influence of rock strength and hole spacing on the cumulative environmental vibration energy of the splitting operation; the functional relationship is: ; in, For reference, the cumulative environmental vibration energy of a single splitting event is expressed in J / event. This is the coefficient representing the influence of lithology on vibration in the splitting environment. The influence coefficient of hole spacing on the vibration of the splitting environment; 11) Determine the influence coefficient of lithology on the vibration of the fracturing environment by rock density; the functional relationship is: ; 12) The influence coefficient of hole spacing on environmental vibration is determined by the maximum splitting force of the splitter. The functional relationship is as follows: ; 13) Establish a single-pile rock-breaking environment vibration response model considering the effects of pile depth, number of boreholes, borehole environment vibration, number of splitting events, and splitting environment vibration; the functional relationship is: ; in, The cumulative environmental vibration energy during rock breaking of a single pile is expressed in kJ.

[0011] Furthermore, the method includes the following steps: 14) Establish a multi-objective weighted decision-making model considering the price, time, and cumulative environmental vibration energy of single-pile rock breaking; the functional relationship is: ; in, Price weighting; Time weighting; As the environmental vibration response weight; This is the price normalization coefficient, with a value ranging from 1 to 20; This is the time normalization coefficient, with a value ranging from 1000 to 2000; The normalization coefficient for cumulative environmental vibration energy ranges from 1 to 10. These are the reference price for rock breaking of a single pile and the upper limit of the budget for single pile construction of the target project, respectively. These are the reference rock-breaking time for a single pile and the upper limit of the construction period for a single pile in the target project, respectively. These are the cumulative environmental vibration energy level of a reference single pile breaking rock and the upper limit of the cumulative environmental vibration energy that the target project can withstand, respectively. 15) Determine the constraints of the multi-objective weighted decision-making model, and determine the minimum hole spacing based on the minimum drilling spacing of the modular pneumatic drilling rig. The maximum hole spacing is determined by the maximum splitting force of the rock splitter and the strength of the target rock. Thus, the constraints of the model are obtained as follows: ; 16) Determine the optimal borehole spacing for rock splitting and breaking in the foundation of transmission line towers in mountainous areas. Use a genetic algorithm to optimize the objective function within the constraints determined in the above steps. The minimum value is reached, and the hole spacing corresponding to this minimum value is the optimal hole spacing for drilling, splitting, and breaking rock in mountainous transmission line tower foundations. ; .

[0012] The beneficial effects of this invention are mainly reflected in: 1. Establish a quantitative model of project price, construction time, environmental vibration response and hole spacing. This model can take into account the coupled effects of multiple factors such as pile hole geometry parameters, rock type differences and equipment performance, and effectively avoid the problem of unstable construction results caused by traditional empirical methods. 2. A weighting method for price, construction period, and environmental vibration response is proposed, which can take into account different construction strategies such as "price priority", "construction period priority" or "safety priority" to quantify the main project objectives; 3. Establish a multi-objective weighted decision-making model that can determine the optimal hole spacing under different construction conditions and engineering objectives, and realize intelligent hole spacing decision-making. Attached Figure Description

[0013] Figure 1 This is a flowchart of a method for determining the spacing of boreholes for rock splitting and breaking in the foundation of power transmission line towers in mountainous areas.

[0014] Figure 2 This is a schematic diagram of a single-pile rock breaking price model.

[0015] Figure 3 This is a schematic diagram of a single pile rock breaking time model.

[0016] Figure 4 This is a schematic diagram of a single pile rock-breaking environment vibration response model.

[0017] Figure 5 This is a schematic diagram of a multi-objective weighted decision-making model.

[0018] Figure 6 It is the optimal hole spacing model curve under different construction conditions and engineering objectives. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings.

[0020] Reference Figures 1-5 A method for determining the spacing of boreholes for rock splitting and breaking in mountainous areas is proposed. This method establishes a mathematical model that considers the coupled effects of multiple factors such as borehole geometry parameters, lithological differences, and equipment performance. It quantifies the functional relationship between engineering price, construction time, environmental vibration response, and borehole spacing, and establishes a multi-objective weighted decision-making model to determine the optimal borehole spacing under different construction conditions and engineering objectives.

[0021] A power transmission line tower foundation excavation project is located in a mountainous area of ​​Jinhua City, Zhejiang Province, requiring the excavation of tuff strata to form three pile foundations. The construction area is situated in a mountainous region with limited transportation, making material transport difficult, and a lack of nearby water sources, rendering water-jet drilling methods unsuitable for the excavation needs. Therefore, this project employs a modular pneumatic drilling rig combined with a hydraulic rock splitter for drilling, rock splitting, and breaking to achieve pile hole excavation. Simultaneously, the proposed multi-objective weighted decision-making method for determining the borehole spacing for power transmission line tower foundation drilling and rock splitting in mountainous areas is used to determine the optimal hole spacing based on different construction conditions and project objectives. The relevant parameters in this embodiment are as follows: 1. Topographical Environment and Lithological Parameters: The construction site is located in a typical mountainous terrain with an average slope of approximately 20° and significant surface elevation differences. The rock mass is relatively intact, and no significant joint or fracture zones were found. The engineering strata are mainly lithostratigraphic, with homogeneous lithology. The uniaxial compressive strength of the rock is [not specified]. Rock density =2650kg / m 3 ; Rock Brinell hardness =300N / mm 2 .

[0022] 2. Surrounding Environment and Project Objectives: Three pile foundations need to be excavated within the construction route of this project, with a pile diameter of [missing information]. The piles are 10m deep. The three pile foundations are located at different points along the railway line, with significantly different surrounding environments. The pile foundation 1 is located near an important transportation base. To minimize the impact of construction on it, the construction period needs to be shortened. The project takes construction time as the main objective, and the weights of price, time and environmental vibration response are allocated as 0.3, 0.6 and 0.1, respectively.

[0023] The terrain around pile foundation 2 is relatively flat and the rock mass has high integrity, providing good construction conditions. The project's main objective is economic efficiency, with the weights for price, time, and environmental vibration response being 0.6, 0.2, and 0.2, respectively.

[0024] The terrain where pile foundation 3 is located is relatively steep, and there is a risk of rockfall on some slopes. Therefore, it is necessary to control the impact of construction time and environmental vibration on slope stability. The project takes construction time and environmental vibration response as the main objectives, and the weight allocation of price, time and environmental vibration response is 0.2, 0.4 and 0.4 respectively.

[0025] The maximum budget for single pile construction in this project The maximum construction period for a single pile is 70,000 yuan. The maximum cumulative environmental vibration energy that the construction site can withstand over 10 days. It is 70 kJ.

[0026] 3. Technical parameters of construction equipment: Maximum splitting force of the rock splitter The splitter weighs 40 kg and has a single-splitting effective depth. The ultimate splitting distance is 100mm; the drill bit radius is 45mm; the drill bit material is cemented carbide; and the Brinell hardness is [not specified]. The number of drill teeth is 8 (the tooth coefficient is 0.8); the minimum drilling spacing of the modular pneumatic drill is 10mm.

[0027] 4. Reference values ​​(based on drilling and rock-breaking operations in formations with a rock strength of 10 MPa) are as follows: Reference lithological parameters: Reference rock strength =10MPa, reference rock density =2500kg / m 3 ; Reference equipment parameters: Maximum splitting force of the reference rock splitter =3900kN, reference splitter mass =40kg; Reference construction parameters: Reference drilling price per linear meter of single hole =100 yuan / m, reference price for a single splitting operation =80 yuan / time, shipping cost of splitting equipment as a reference for a single splitting operation. =20 yuan / time, reference price for single-pile rock breaking =40,000 yuan; Reference hole spacing =30mm; Reference time for rock breaking per meter =0.5d / m, reference single pile rock breaking time =4 days; reference to the cumulative environmental vibration energy per linear meter of a single borehole =200J / m, reference cumulative environmental vibration energy of a single splitting event =100J / cycle, reference single pile rock breaking cumulative environmental vibration energy level =40kJ.

[0028] Reference rock breaking time influence coefficient: Hole spacing time influence coefficient =0.01, Lithology Time Influence Coefficient =0.05, Splitting force time influence coefficient =0.01; Reference normalization coefficient: Price normalization coefficient =10; Time normalization coefficient =1200; Normalized coefficient of cumulative environmental vibration energy =5.

[0029] The method for determining the spacing of boreholes for rock splitting and breaking in mountainous areas for power transmission line tower foundation drilling in this embodiment includes the following steps: 1) Establish a single borehole price model. Based on the reference borehole price per linear meter, reference rock strength, and rock strength, establish a single borehole price model, the expression of which is: ; 2) Determine the drilling resistance index. Based on the Brinell hardness of the drill bit and the Brinell hardness of the rock, determine the drilling resistance index. Its expression is: ; 3) Establish a single-splitting price model. Based on the reference price for a single splitting operation, the reference hole spacing, the reference equipment transportation cost for a single splitting operation, the maximum splitting force of the reference splitter, and the reference splitter weight, establish a single-splitting price model, the expression of which is:

[0030] in, Price per splitting operation, unit: yuan / operation; This is a reference price for a single splitting operation, in yuan per operation. The shipping cost for a single splitting operation is in yuan per operation. Hole spacing, unit: mm; Reference hole spacing, unit: mm; The maximum splitting force of the reference splitter is expressed in kN. The maximum splitting force of the target engineering rock splitter, in kN; For reference, the mass of the splitter is expressed in kg. The target engineering rock splitter mass, unit: kg 4) Calculate the number of boreholes and the number of splitting operations. The radius of the splitting hole is determined by the drill bit radius. =45mm, calculate the number of boreholes based on the pile diameter: ; 5) Calculate the number of splitting operations, and determine the splitting hole radius based on the drill bit radius. =45mm, calculate the number of splitting fractures based on pile diameter and pile depth: ; 6) Establish a single-pile rock breaking price model. Based on the price model for a single borehole, the number of boreholes, the price model for a single splitting operation, and the number of splitting operations, establish a single-pile rock breaking price model. Its expression is: ; 7) Establish a single-pile rock-breaking time model, based on the influence coefficient of hole spacing time. =0.01, Lithology Time Influence Coefficient =0.05, Splitting force time influence coefficient =0.01, reference hole spacing, rock parameters, and equipment parameters, establish a single pile rock breaking time model, the expression of which is: ; 8) Establish a borehole environmental vibration response model. Based on the rock strength and the cumulative environmental vibration energy per meter of a single borehole, establish a borehole environmental vibration response model, the expression of which is: ; 9) Determine the influence coefficient of lithology on borehole environment vibration. The influence coefficient is determined based on the reference rock density and the actual rock density. ; 10) Establish a vibration response model for the splitting environment. Based on the rock strength, the cumulative environmental vibration energy of a reference single splitting, and the reference hole spacing, establish a vibration response model for the splitting environment. Its expression is: ; 11) Determine the influence coefficient of lithology on the vibration of the fracturing environment based on rock density: ; 12) Determine the influence coefficient of hole spacing on environmental vibration based on the maximum splitting capacity of the splitter: ; 13) Establish a single-pile rock-breaking environment vibration response model. Based on the single-split environment vibration response model, the single borehole environment vibration response model per meter, the number of boreholes, and the number of splits, establish a single-pile rock-breaking environment vibration response model, the expression of which is: ; 14) Establish a multi-objective weighted decision-making model. Based on the on-site construction conditions and project objectives, and with the primary control objective of ensuring construction safety while achieving economical construction of the tower foundation excavation, determine the weights for price, time, and environmental vibration response of pile foundation 1 as 0.3, 0.6, and 0.1, respectively; for pile foundation 2 as 0.6, 0.2, and 0.2, respectively; and for pile foundation 3 as 0.6, 0.2, and 0.2, respectively. Based on the specific forms of the three models—single pile rock breaking price, total time, and environmental vibration response—the multi-objective weighted decision-making model for pile foundation 1 is established as follows: ; The multi-objective weighted decision-making model for pile foundation 2 is as follows: ; Multi-objective weighted decision model for pile foundation 3: ; 15) Determine the constraints of the multi-objective weighted decision-making model. Based on the minimum drilling spacing of the modular pneumatic drilling rig and the ultimate splitting distance of the rock splitter, the model constraints are determined as follows: ; 16) Determine the optimal borehole spacing for rock splitting and breaking in the tower foundations of power transmission lines in mountainous areas. A genetic algorithm is used to optimize the objective function within the constraints determined in the above steps. The minimum value is reached, and the hole spacing corresponding to this minimum value is the optimal hole spacing for drilling, splitting, and breaking rock in mountainous transmission line tower foundations. Table 1 shows the objective function and the corresponding optimal hole spacing for different pile foundation conditions;

[0031] The embodiments described in this specification are merely examples of implementations of the inventive concept and are for illustrative purposes only. The scope of protection of this invention should not be considered limited to the specific forms described in these embodiments; rather, it extends to equivalent technical means conceived by those skilled in the art based on the inventive concept.

Claims

1. A method for determining the spacing of boreholes for rock splitting and breaking in mountainous areas for power transmission line tower foundations, characterized in that, By establishing a mathematical model that considers the coupled effects of multiple factors such as pile hole geometry parameters, lithological differences, and equipment performance, the functional relationship between project price, construction time, environmental vibration response, and hole spacing is quantified. A multi-objective weighted decision-making model is then established to determine the optimal hole spacing under different construction conditions and project objectives.

2. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 1, characterized in that, The method includes the following steps: 1) Establish a single borehole price model that can take into account the impact of rock strength on energy consumption and drill bit wear; 2) The drilling resistance index is determined by the hardness of the drill bit material; 3) Establish a single-splitting price model that considers the coupled effects of hole spacing, rock strength, equipment transportation costs, and rock splitter performance; 4) Based on hole spacing , radius of splitting hole and pile diameter Determine the number of boreholes Calculate the number of boreholes; 5) Determined by the number of boreholes and pile depth and the effective depth of a single split Calculate the number of splits ; 6) Establish a single-pile rock-breaking price model that considers the influence of pile hole geometry parameters, drilling price, number of boreholes, splitting price, and number of splitting operations; the functional relationship is: ； in, Price for single-pile rock breaking, unit: 10,000 yuan.

3. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 2, characterized in that, The method includes the following steps: 7) Establish a single-pile rock breaking time model considering the effects of hole spacing, rock strength, and the maximum splitting force of the rock splitter; the functional relationship is: ； in, The time for a single pile to break rock is expressed in days (d). The reference time for rock breaking per meter is expressed in d / m. The hole spacing time influence coefficient is determined by the ratio of hole spacing to split hole radius; The lithological time influence coefficient is determined by rock strength; The splitting force time influence coefficient is determined by the equipment performance.

4. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 3, characterized in that, The method includes the following steps: 8) Establish an environmental vibration response model for a single borehole per meter, taking into account the influence of rock strength on the cumulative environmental vibration energy of the drilling operation; 9) Determine the influence coefficient of lithology on borehole environment vibration by using rock density; 10) Establish a single-stage splitting environmental vibration response model that considers the influence of rock strength and hole spacing on the cumulative environmental vibration energy of the splitting operation; 11) Determine the influence coefficient of lithology on the vibration of the splitting environment by rock density; 12) Determine the influence coefficient of hole spacing on environmental vibration by using the maximum splitting force of the splitter; 13) Establish a single-pile rock-breaking environment vibration response model considering the effects of pile depth, number of boreholes, borehole environment vibration, number of splitting events, and splitting environment vibration; the functional relationship is: ； in, The cumulative environmental vibration energy during rock breaking of a single pile is expressed in kJ.

5. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 4, characterized in that, The method includes the following steps: 14) Establish a multi-objective weighted decision-making model considering the price, time, and cumulative environmental vibration energy of single-pile rock breaking; the functional relationship is: ； in, Price weighting; Time weighting; As the environmental vibration response weight; This is the price normalization coefficient; The time normalization coefficient; This is the normalization coefficient for cumulative environmental vibration energy; These are the reference price for rock breaking of a single pile and the upper limit of the budget for single pile construction of the target project, respectively. These are the reference rock-breaking time for a single pile and the upper limit of the construction period for a single pile in the target project, respectively. These are the cumulative environmental vibration energy level of a reference single pile breaking rock and the upper limit of the cumulative environmental vibration energy that the target project can withstand, respectively. 15) Determine the constraints of the multi-objective weighted decision-making model; 16) Determine the optimal hole spacing for drilling and rock splitting in the foundation of power transmission line towers in mountainous areas.

6. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 5, characterized in that, In step 15), the minimum hole spacing is determined by the minimum drilling spacing of the modular pneumatic drilling rig. The maximum hole spacing is determined by the maximum splitting force of the rock splitter and the strength of the target rock. Thus, the constraints of the model are obtained as follows: .

7. The method for determining the spacing of boreholes for rock splitting and breaking in mountainous transmission line tower foundations as described in claim 5, characterized in that, In step 16), a genetic algorithm is used to optimize the objective function within the constraints determined in the above steps. The minimum value is reached, and the hole spacing corresponding to this minimum value is the optimal hole spacing for drilling, splitting, and breaking rock in mountainous transmission line tower foundations. ; 。

Images