Deepwater large-volume bearing platform foundation pit refined blasting excavation construction method

Abstract

The invention relates to the technical field of bridge construction, and discloses a refined blasting excavation construction method for a deepwater large-volume bearing platform foundation pit, which comprises the following steps of: preparing before construction, carrying out underwater topographic survey and three-dimensional modeling before excavation after preparing, carrying out covering layer excavation before blasting, and carrying out topographic survey and three-dimensional modeling after the covering layer excavation. Blasting parameter design and trial blasting are carried out before blasting, blasting parameters are optimized after trial blasting, and underwater blasting construction and blasting vibration monitoring are carried out; after blasting, measurement and three-dimensional modeling updating are carried out on the excavated underwater terrain; according to the method, through the adoption of the construction technology of refined control blasting, on the basis of ensuring the blasting effect, the use amount of explosives and the investment and labor cost of ship equipment are reduced, the construction efficiency is improved, the overall level of underwater blasting operation is improved, and the construction cost is reduced. And during blasting construction, the influence on the life of surrounding residents is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and more specifically to a refined blasting excavation construction method for a deep-water large-volume foundation pit. Background Art

[0002] In the complex environment of modern bridge construction, engineering projects often face a series of challenges. As a key part of the foundation support structure, the foundation excavation construction of the foundation is particularly important. When the foundation is located at the bottom of the riverbed, deep from the water surface, far from the shore, and the riverbed geology is hard rock, the foundation pit of the foundation cannot be excavated by traditional long-arm excavators. It can be excavated by deep-water drilling and blasting. Due to factors such as limited underwater vision and high safety risks of underwater operations, compared with land blasting, underwater deep foundation pit blasting excavation faces many challenges such as the inability to visually observe the underwater terrain, low underwater terrain measurement accuracy, high position control requirements, and difficulty in quality control of underwater blasting operations.

[0003] Therefore, there is an urgent need for refined blasting and excavation construction methods for deep-water large-volume foundation pits. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, the implementation regulations of the present invention provide a refined blasting and excavation construction method for a deep-water large-volume foundation pit to solve the technical problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: A deep-water large-volume foundation pit refined blasting excavation construction method, comprising the following steps:

[0006] Step S1, perform pre-construction preparation, and then perform underwater topographic survey and three-dimensional modeling before excavation;

[0007] Step S2, excavating the overburden before blasting, and performing topographic survey and three-dimensional modeling after excavating the overburden;

[0008] Step S3, design blasting parameters and conduct test blasting before blasting, optimize blasting parameters after test blasting, conduct underwater blasting construction and blasting vibration monitoring;

[0009] Step S4: after blasting, measure the excavated underwater terrain and update the three-dimensional model;

[0010] Step S5, evaluate the blasting effect and continue blasting. After the blasting is completed, clean up and level the ground and sweep the bed for acceptance.

[0011] In a preferred embodiment, the pre-construction preparation in step S1 includes three parts: determining the measurement period, determining the wiring method, and determining the measurement density. The measurement period is determined to determine the measurement time for key construction nodes, underwater terrain, and blasting effect nodes. The wiring method is determined to use a grid-based uniform wiring method as the main method, and the distance between measurement points is reduced and the number of measurements is increased in key areas. The measurement density is determined to use an adjustment value T to adjust the measurement density. Five gears are set in terms of measurement density, from low to high, namely, the first gear, the second gear, the third gear, the fourth gear, and the fifth gear.

[0012] In a preferred embodiment, the calculation formula of the adjustment value T is: Where n means dividing the total area where blasting construction is currently being carried out into n areas, i means that the current area is the i-th area, FBi is the distribution quantity of rocks in the i-th area, QFi is the maximum drop fluctuation data in the i-th area, the unit is centimeter, k1 and k2 are weights, DC is the number of geological faults in the total area of ​​blasting construction, and the measurement density is determined according to the specific gear position of the adjustment value T among the five gears.

[0013] In a preferred embodiment, in step S1, a planned wiring method is used to measure underwater terrain, the collected underwater terrain data is processed using Surfer technology, the data is imported into Surfer software, and the three-dimensional modeling function is used to convert the terrain surface into a high-precision three-dimensional terrain model.

[0014] In a preferred embodiment, in step S2, after the overburden excavation operation is completed, the excavation boundary, depth change area and geological condition change area are measured and terrain data are obtained, and the underwater terrain measurement data of the overburden excavation is imported into the three-dimensional terrain modeling software Surfer, and compared with the original terrain data, and the terrain height change data, slope change data and new rock exposure data are extracted to make underwater geological judgments.

[0015] In a preferred embodiment, in step S3, when designing blasting parameters, the safe allowable distance R of blasting vibration is calculated, and the calculation formula is: Where K is the coefficient of terrain and geological conditions between the blasting point and the calculated protection object, V is the safe allowable vibration velocity of the geological point where the protection object is located, Q is the amount of explosives, α is the attenuation index, and the calculation formula of the explosive amount Q is Q=q0×a×b×H0, where q0 is the unit explosive consumption of underwater blasting, a is the hole spacing of the boreholes, b is the row spacing of the boreholes, H0 is the designed blasting rock layer thickness, and the blasting parameters are designed based on the safe allowable distance R of blasting vibration.

[0016] In a preferred embodiment, the underwater blasting construction process during blasting in step S3 is drilling, charging, connecting, warning, detonating, and slag cleaning, a total of six steps. When drilling, a drilling rig ship is selected to drill according to the designed drilling parameters, the hole position and drilling depth are consistent with the drilling parameters, and a dual GPS measurement and positioning system is used during drilling to locate the drilling position.

[0017] In a preferred embodiment, in step S5, the blasting effect is evaluated using an evaluation value P, and the calculation formula of the evaluation value P is: Where JS is the peak acceleration of vibration during blasting, YZ is the allowable vibration threshold of the building, PZ is the flatness after blasting, X1 is the flatness correction coefficient, PD is the slope after blasting, X2 is the slope correction coefficient, and both the flatness correction coefficient X1 and the slope correction coefficient X2 are positive numbers, sgn is the rounding function, and when the calculated value of the evaluation value P is 0 or a negative number, the current blasting is directly evaluated as unqualified.

[0018] In a preferred embodiment, when the calculated value of the evaluation value P is a positive number, the evaluation value P is compared with the first blasting threshold BY1 and the second blasting threshold BY2. The first blasting threshold BY1 is less than the second blasting threshold BY2. When the evaluation value P is less than the first blasting threshold BY1, the current blasting does not meet expectations. When the first blasting threshold BY1≤evaluation value P≤first blasting threshold BY1, the current blasting meets expected requirements. When the evaluation value P>the second blasting threshold BY2, the current blasting meets expected requirements, but the amount of explosives needs to be reduced.

[0019] In a preferred embodiment, the measurements in step S1, step S2 and step S4 are all carried out using an intelligent unmanned survey ship system, which performs full-process and full-cycle measurements of the underwater terrain. When the three parts of determining the measurement period, determining the wiring method and determining the measurement density in the pre-construction preparation of step S1 are completed, the intelligent unmanned survey ship system provides data.

[0020] Technical effects and advantages of the present invention:

[0021] 1. The present invention adopts the construction technology of finely controlled blasting, which reduces the amount of explosives, the investment in ship equipment and the manpower cost on the basis of ensuring the blasting effect, improves the construction efficiency, improves the overall level of underwater blasting operations, improves the safety of personnel during the operation, and improves the use efficiency of construction ships. When carrying out blasting construction, it can avoid damage to surrounding power towers and houses, and reduce the impact on the lives of surrounding residents;

[0022] 2. The present invention calculates the adjustment value T through the distribution of rocks in the entire construction area, the maximum drop fluctuation data and the number of geological faults, which can accurately reflect the geological conditions in the total area of ​​blasting construction. At this time, the calculated adjustment value T is matched with the gear position to adapt to different geological conditions, ensuring that the present application can perform accurate measurements in different geological environments;

[0023] 3. The present invention calculates the evaluation value P. When the evaluation value P is negative, the peak acceleration of the vibration during blasting reaches or even exceeds the allowable vibration threshold of the building. Therefore, adjustment is made directly, and the blasting is unqualified. When the calculated value of the evaluation value P is a positive number, the peak acceleration of the vibration during blasting does not reach the allowable vibration threshold. The amount of explosives is adjusted according to the comparison results between the evaluation value P and the first blasting threshold BY1 and the second blasting threshold BY2. When the blasting meets the expected requirements, the explosives used are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the construction process steps of the present invention.

[0025] Figure 2 It is a schematic diagram of the construction process flow of the present invention.

[0026] Figure 3 It is a schematic diagram of foundation pit measurement wiring of the present invention.

[0027] Figure 4 It is the three-dimensional topographic map before foundation pit excavation of the present invention.

[0028] Figure 5 It is a three-dimensional topographic map after excavation of the foundation pit covering layer of the present invention.

[0029] Figure 6 It is a three-dimensional topographic map after the foundation pit excavation of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are only examples. The deep-water large-volume foundation pit refined blasting and excavation construction method involved in the present invention is not limited to the various structures recorded in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0031] Embodiment 1

[0032] Reference Figure 1 , Figure 2 as well as Figure 6 The present invention provides a deep-water large-volume foundation pit refined blasting excavation construction method, comprising the following steps:

[0033] Step S1, perform pre-construction preparation, and then perform underwater topographic survey and three-dimensional modeling before excavation;

[0034] Step S2, excavating the overburden before blasting, and performing topographic survey and three-dimensional modeling after excavating the overburden;

[0035] Step S3, design blasting parameters and conduct test blasting before blasting, optimize blasting parameters after test blasting, conduct underwater blasting construction and blasting vibration monitoring;

[0036] Step S4: after blasting, measure the excavated underwater terrain and update the three-dimensional model;

[0037] Step S5, evaluate the blasting effect and continue blasting. After the blasting is completed, clean up and level the ground and sweep the bed for acceptance.

[0038] In the embodiment of the present application, when conducting blasting excavation of a large-volume foundation pit in deep water, the present application utilizes an intelligent unmanned survey ship system to dynamically adjust the measurement period, wiring method and measurement density according to factors such as the complexity of the underwater terrain, accurately collect terrain data, and provide a basis for subsequent underwater terrain three-dimensional modeling and blasting construction. Based on the measured terrain data and the physical and mechanical properties of rocks, a three-dimensional model established in combination with Surfer 3D technology is used to reasonably optimize blasting parameters by considering factors such as explosive performance and blasting methods. By controlling various processes such as drilling, charging, and detonation, rock crushing and foundation pit excavation are achieved, while using real-time blasting vibration measurement data feedback to adjust parameters to ensure blasting effect and safety. The measured underwater terrain data is converted into a high-precision three-dimensional model through Surfer modeling software, underwater terrain data at different construction stages are collected, and a Surfer three-dimensional model is established to achieve full-cycle topographic visualization of the underwater foundation pit location.

[0039] Reference Figure 3 In step S1, the pre-construction preparation includes three parts: determining the measurement period, determining the wiring method, and determining the measurement density. The measurement period is determined to determine the measurement time for key construction nodes, underwater terrain, and blasting effect nodes. The wiring method is determined to use a grid-based uniform wiring method as the main method. The distance between the measurement points is reduced and the number of measurements is increased for key parts. The measurement density is determined to use an adjustment value T for measurement density adjustment. Five gears are set in terms of measurement density, which are the first gear, the second gear, the third gear, the fourth gear, and the fifth gear from low to high. The calculation formula of the adjustment value T is: Where n means dividing the total area where blasting construction is currently being carried out into n areas, i means that the current area is the i-th area, FBi is the distribution quantity of rocks in the i-th area, QFi is the maximum drop fluctuation data in the i-th area, the unit is centimeter, k1 and k2 are weights, DC is the number of geological faults in the total area of ​​blasting construction, and the measurement density is determined according to the specific gear position of the adjustment value T among the five gears.

[0040] In the embodiment of the present application, when preparing before construction, the method includes three parts: determining the measurement period, determining the wiring method, and determining the measurement density. When determining the measurement period, the measurement time is determined for the key construction nodes, underwater terrain, and blasting effect nodes to ensure that the data of each key stage can be collected comprehensively and timely. Through in-depth comparative analysis of the measurement data of different periods, the terrain changes, data differences, and other information of each stage are recorded in detail. These data are used to guide subsequent construction and provide reliable data support for decision-making during the construction process. When determining the wiring method, the grid-based uniform wiring method is used as the leading method. The distance between the measurement points in key parts is reduced, the number of measurements is increased, and the frequency and signal emission intensity of the depth sounding instrument are increased to achieve the purpose of improving the measurement accuracy. When determining the measurement density, the adjustment value T is used for adjustment. When calculating the adjustment value T, the calculated adjustment value T can accurately reflect the geological conditions in the total area of ​​blasting construction through the distribution number of rocks in the entire construction area, the maximum drop fluctuation data, and the number of geological faults. At this time, the calculated adjustment value T is matched with the gear to adapt to different geological conditions, ensuring that the present application can perform accurate measurements in different geological environments.

[0041] Reference Figure 4 and Figure 5 In the step S1, underwater terrain measurement is performed using a planned wiring method, the collected underwater terrain data is processed using Surfer technology, the data is imported into Surfer software, and the terrain surface is converted into a high-precision three-dimensional terrain model using a three-dimensional modeling function. In the step S2, after the overburden excavation operation is completed, the excavation boundary, depth change area and geological condition change area are measured and terrain data are obtained, and the underwater terrain measurement data after the overburden excavation is imported into the three-dimensional terrain modeling software Surfer, and compared with the original terrain data, terrain height change data, slope change data and new rock exposure data are extracted to make underwater geological judgments.

[0042] In the embodiment of the present application, the underwater terrain measurement before excavation is based on the planned wiring method and related parameters, and high-precision depth sounders, sonars and other equipment are used to obtain information such as water depth and underwater terrain undulations. These data will be transmitted and stored in real time to ensure that the underwater terrain data before excavation is accurate, comprehensive and without omissions, and the terrain surface is converted into a high-precision three-dimensional terrain model to visualize the underwater terrain, which is convenient for construction personnel to better understand and analyze the underwater construction environment. After the excavation of the overburden layer is completed, the measurement work is carried out according to the pre-planned measurement time period, wiring method and measurement density, focusing on the excavation boundary, areas with obvious depth changes, and obvious changes in geological conditions, etc., increasing the density of measurement points in these areas, and obtaining more detailed terrain data. By comparing the gap between the three-dimensional terrain models at different stages (before and after excavation), the changes in terrain height, slope changes, exposure of new rocks, etc. can be clearly seen, thereby judging the underwater geology.

[0043] Furthermore, in step S3, when designing blasting parameters, the safe allowable distance R of blasting vibration is calculated, and the calculation formula is: Wherein K is the coefficient of the terrain and geological conditions between the blasting point and the calculated protection object, V is the safe allowable vibration speed of the geological point where the protection object is located, Q is the amount of explosives, α is the attenuation index, and the calculation formula of the explosive amount Q is Q=q0×a×b×H0, where q0 is the unit explosive consumption of underwater blasting, a is the hole spacing of the boreholes, b is the row spacing of the boreholes, H0 is the designed blasting rock layer thickness, and the blasting parameters are designed based on the safe allowable distance R of blasting vibration. The underwater blasting construction process during blasting in step S3 is drilling, charging, connecting, warning, detonating, and slag cleaning, a total of six steps. When drilling, a drilling rig is selected to drill according to the designed drilling parameters, the hole position and the drilling depth are consistent with the drilling parameters, and a dual GPS measurement and positioning system is used during drilling to locate the drilling position.

[0044] In the embodiment of the present application, when blasting is performed, the blasting needs to ensure safety. Therefore, the present application calculates the safe allowable distance R of blasting vibration, and designs blasting parameters according to the calculated safe allowable distance R of blasting vibration to avoid affecting the surroundings. When designing blasting parameters, a reasonable mesh spacing and row spacing are determined according to the size, shape and rock distribution of the blasting area to evenly distribute the explosive explosion energy in the rock and achieve a better crushing effect. Considering the above factors comprehensively, the mesh parameters of this type of project can be determined according to the following data:

[0045] Hole spacing: 2.5m (the drilling rig fixed frame is 2.5 meters apart);

[0046] Row spacing: 1.5m to 2m. For hard rocks with good integrity, 1.5m is recommended. For weak structures and those that are difficult to drill holes, 2m is recommended.

[0047] Layer thickness: Based on the requirements of the surrounding protected objects for vibration speed, the efficiency of underwater rock transportation, and the thickness of the rock itself, the underwater deep hole blasting thickness is controlled within 6 meters to achieve the best blasting effect;

[0048] The drilling depth is Δh = 1.5m-2m, and the rock hardness is set to a maximum value;

[0049] Charge factor: It is determined based on factors such as the hardness of the rock and the development of cracks. In rocks with higher hardness, the charge factor may need to be appropriately increased to ensure that the explosive energy is sufficient to break the rock; while for rocks with more cracks, the charge factor needs to be carefully adjusted to avoid over-blasting.

[0050] Charging interval length: 0.3m-0.6m;

[0051] Inter-hole interval: 103ms;

[0052] Interval within the hole: 47ms.

[0053] Other factors that should be considered for underwater charge include: the charge should reach about 75% of the drilling depth, the specifications of the charge roll, the convenience of processing the charge column, increasing the charge in thinner rock layers to reduce over-depth, etc. When the hole depth reaches 5 meters or more, interval charging is used with an interval length of 0.5m.

[0054] Furthermore, in step S5, the blasting effect is evaluated using an evaluation value P, and the calculation formula of the evaluation value P is: Wherein JS is the peak acceleration of vibration during blasting, YZ is the allowable vibration threshold of the building, PZ is the flatness after blasting, X1 is the flatness correction coefficient, PD is the slope after blasting, X2 is the slope correction coefficient, and both the flatness correction coefficient X1 and the slope correction coefficient X2 are positive numbers, sgn is the rounding function, when the value calculated by the evaluation value P is 0 or a negative number, the current blasting is directly evaluated as unqualified, when the value calculated by the evaluation value P is a positive number, the evaluation value P is compared with the first blasting threshold BY1 and the second blasting threshold BY2, the first blasting threshold BY1<the second blasting threshold BY2, when the evaluation value P<the first blasting threshold BY1, the current blasting does not meet expectations, when the first blasting threshold BY1≤evaluation value P≤first blasting threshold BY1, the current blasting meets the expected requirements, when the evaluation value P>the second blasting threshold BY2, the current blasting meets the expected requirements, but the amount of explosives needs to be reduced.

[0055] In the embodiment of the present application, when evaluating the blasting effect, the present application adopts the sgn rounding function. When the sgn rounding function is operated, it outputs 1 when a positive number is input, outputs 0 when 0 is input, and outputs -1 when a negative number is input. Therefore, when the value calculated by the evaluation value P of the present application is 0 or a negative number, the peak acceleration of the vibration during the blasting reaches or even exceeds the allowable vibration threshold of the building. Therefore, adjustment is made directly, and the blasting is unqualified. When the value calculated by the evaluation value P is a positive number, the peak acceleration of the vibration during the blasting does not reach the allowable vibration threshold. The amount of explosives is adjusted according to the comparison results of the evaluation value P with the first blasting threshold BY1 and the second blasting threshold BY2. When the blasting meets the expected requirements, the explosives used are saved.

[0056] Furthermore, the measurements in step S1, step S2 and step S4 all adopt an intelligent unmanned survey ship system, which performs full-process and full-cycle measurements of the underwater terrain, and when the three parts of determining the measurement time period, determining the wiring method and determining the measurement density in the pre-construction preparation of step S1 are completed, the intelligent unmanned survey ship system provides data.

[0057] In the embodiment of the present application, an intelligent unmanned survey ship system is used to conduct full-process and full-cycle measurements of the underwater terrain, intelligently plan measurement time periods, explore efficient wiring methods, and set scientific measurement densities, so as to provide sufficient and effective three-dimensional data for establishing a three-dimensional model of the underwater terrain, thereby realizing refined management and intelligent regulation of underwater terrain measurements.

[0058] Embodiment 2

[0059] The deep-water large-volume foundation pit refined blasting excavation construction method applied in the No. 1 section of the S514 Nanning Jiangxi to Tanluo Highway

[0060] The planned waterway grade of the Zuojiang River section crossed by the Zhongleng Zuojiang Bridge in the No. 1 section of the S514 Nanning Jiangxi to Tanluo Highway is a Class II waterway. The average water depth of the construction water area is 14 meters, and the deepest reaches 16.6 meters. The 1# and 2# main pier caps of the Zhongleng Zuojiang Bridge are covered by rock layers, which need to be cleaned before construction. There are important building facilities such as power towers, fish ponds, and bridge pile foundations in the surrounding area, which makes the construction difficult. The project applies the "Deep Water Large Volume Cap Foundation Pit Refined Blasting Excavation Construction Method". After excavation, the size, flatness and base bearing capacity of the foundation pit meet the subsequent construction requirements. The project completed the task 26 days ahead of schedule, saving about 20% of the cost, and effectively controlling the blasting vibration. The surrounding buildings were not affected or damaged. The final results were remarkable and recognized and praised by all parties, providing a successful example for similar projects.

[0061] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The units and algorithm steps of each example described in the embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0062] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0063] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0064] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The refined blasting excavation construction method for deep-water large-volume foundation pit is characterized by: The following steps are involved: Step S1, perform pre-construction preparation, and then perform underwater topographic survey and three-dimensional modeling before excavation; Step S2, excavating the overburden before blasting, and performing topographic survey and three-dimensional modeling after excavating the overburden; Step S3, design blasting parameters and conduct test blasting before blasting, optimize blasting parameters after test blasting, conduct underwater blasting construction and blasting vibration monitoring; Step S4: After blasting, measure the underwater terrain and update the 3D model Step S5, evaluate the blasting effect and continue blasting. After the blasting is completed, clean up and level the ground and sweep the bed for acceptance.

2. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: The pre-construction preparation in step S1 includes three parts: determining the measurement period, determining the wiring method, and determining the measurement density. The measurement period is determined to determine the measurement time for key construction nodes, underwater terrain, and blasting effect nodes. The wiring method is determined to use a grid-based uniform wiring method as the main method, and the distance between measurement points is reduced and the number of measurements is increased in key areas. The measurement density is determined to use an adjustment value T to adjust the measurement density. Five gears are set in terms of measurement density, which are the first gear, the second gear, the third gear, the fourth gear, and the fifth gear from low to high.

3. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: The calculation formula of adjustment value T is: Where n means dividing the total area where blasting construction is currently being carried out into n areas, i means that the current area is the i-th area, FBi is the distribution quantity of rocks in the i-th area, QFi is the maximum drop fluctuation data in the i-th area, the unit is centimeter, k1 and k2 are weights, DC is the number of geological faults in the total area of ​​blasting construction, and the measurement density is determined according to the specific gear position of the adjustment value T among the five gears.

4. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: In the step S1, the underwater terrain is measured by using a planned wiring method, the collected underwater terrain data is processed by using Surfer technology, the data is imported into Surfer software, and the terrain surface is converted into a high-precision three-dimensional terrain model using a three-dimensional modeling function.

5. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: In step S2, after the excavation of the overburden layer is completed, the excavation boundary, the depth change area and the geological condition change area are measured and the terrain data is obtained. The underwater terrain measurement data after the overburden layer excavation is imported into the three-dimensional terrain modeling software Surfer, and compared with the original terrain data, the terrain height change data, the slope change data and the new rock exposure data are extracted to make an underwater geological judgment.

6. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: In step S3, when designing blasting parameters, the safe allowable distance R of blasting vibration is calculated, and the calculation formula is: Where K is the coefficient of terrain and geological conditions between the blasting point and the calculated protection object, V is the safe allowable vibration velocity of the geological point where the protection object is located, Q is the amount of explosives, α is the attenuation index, and the calculation formula of the explosive amount Q is Q=q0×a×b×H0, where q0 is the unit explosive consumption of underwater blasting, a is the hole spacing of the boreholes, b is the row spacing of the boreholes, H0 is the designed blasting rock layer thickness, and the blasting parameters are designed based on the safe allowable distance R of blasting vibration.

7. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: The underwater blasting construction process during blasting in step S3 is drilling, charging, connecting, warning, detonating, and slag cleaning, a total of six steps. When drilling, a drilling rig ship is selected to drill according to the designed drilling parameters, the hole position and drilling depth are consistent with the drilling parameters, and a dual GPS measurement and positioning system is used during drilling to locate the drilling position.

8. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: In step S5, the blasting effect is evaluated using an evaluation value P, and the calculation formula of the evaluation value P is: Where JS is the peak acceleration of vibration during blasting, YZ is the allowable vibration threshold of the building, PZ is the flatness after blasting, X1 is the flatness correction coefficient, PD is the slope after blasting, X2 is the slope correction coefficient, and both the flatness correction coefficient X1 and the slope correction coefficient X2 are positive numbers, sgn is the rounding function, and when the calculated value of the evaluation value P is 0 or a negative number, the current blasting is directly evaluated as unqualified.

9. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: When the calculated value of the evaluation value P is a positive number, the evaluation value P is compared with the first blasting threshold BY1 and the second blasting threshold BY2. The first blasting threshold BY1 is less than the second blasting threshold BY2. When the evaluation value P is less than the first blasting threshold BY1, the current blasting does not meet expectations. When the first blasting threshold BY1≤evaluation value P≤first blasting threshold BY1, the current blasting meets the expected requirements. When the evaluation value P>the second blasting threshold BY2, the current blasting meets the expected requirements, but the amount of explosives needs to be reduced.

10. The deep-water large-volume foundation pit refined blasting excavation construction method according to claim 1 is characterized by: The measurements in step S1, step S2 and step S4 all adopt an intelligent unmanned survey ship system, which performs full-process and full-cycle measurements of the underwater terrain. When the three parts of determining the measurement period, determining the wiring method and determining the measurement density in the pre-construction preparation of step S1 are completed, the intelligent unmanned survey ship system provides data.

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