Views: 0 Author: Site Editor Publish Time: 2025-10-22 Origin: Site
In the field of modern engineering construction, from towering skyscrapers piercing the clouds to magnificent bridges spanning rivers, lakes, and seas, and underground rail transit systems traversing cities, pile foundations play an indispensable role. Like the "anchor of stability" for buildings, they provide a firm and reliable support for the entire engineering structure. As the core equipment in pile foundation construction, the rotary drilling rig has become an essential force in foundational work, widely utilized in various large-scale construction projects due to its advantages such as rapid hole-forming, strong adaptability to diverse geological conditions, and convenient relocation.
Hole-forming accuracy, as a core indicator in the construction process of rotary drilling rigs, is akin to the cornerstone of a skyscraper—its importance is self-evident. It directly impacts the load-bearing capacity of pile foundations, much like how a sturdy cornerstone supports a towering edifice. Precise hole-forming is the prerequisite for ensuring that pile foundations can stably bear the weight of superstructures. Additionally, hole-forming accuracy profoundly influences the stability of the pile body, ensuring that the pile remains vertical and secure even under complex geological conditions and external forces. Furthermore, high-precision hole-forming reduces maintenance costs and safety risks associated with foundation issues in the long term, providing robust support for the stable operation of the entire project. If hole-forming accuracy deviates from standards, the load-bearing capacity of pile foundations may fail to meet design requirements, much like an unstable foundation leading to severe incidents such as settlement, tilting, or even collapse during use. This not only results in substantial economic losses but also poses serious threats to human safety. Therefore, in-depth research on parameter settings and operational techniques for controlling hole-forming accuracy in rotary drilling rigs holds immense practical significance for improving project quality, ensuring construction safety, reducing costs, and advancing the development of the entire construction industry.
In pile foundation construction, the accuracy of rotary drilling rigs in forming holes is of great significance, as it is closely related to the bearing capacity and stability of the pile foundation, directly affecting the quality and safety of the entire project.
The accuracy of hole formation is crucial to the bearing capacity of pile foundations. Taking a large commercial building as an example, the design requires the pile foundation to support loads from the superstructure weighing tens of thousands of tons, and high-precision hole formation is the foundation for achieving this goal. If deviations occur during hole formation, resulting in an actual diameter smaller than the design requirement, the contact area between the pile and surrounding soil will decrease. This leads to the inability to meet the designed expectations for side friction resistance and end bearing capacity, much like a weak pillar struggling to support a heavy structure. Over time, the pile foundation may settle due to insufficient bearing capacity or even fracture, endangering the safety of the entire building structure.
The stability of the pile body also depends on the accuracy of hole formation. In areas with complex geological conditions, such as those with uneven soil layers or high groundwater levels, the pile must maintain good verticality and stability to effectively resist external forces from all directions. In one case, during the construction of a bridge's pile foundation, the verticality deviation of the rotary drilling rig was significant. After the bridge was completed and opened to traffic, the pile body tilted due to external forces like vehicle loads and water erosion, leading to localized structural deformation of the bridge. Emergency reinforcement measures were then required, which not only consumed substantial manpower, materials, and time but also severely impacted traffic.
The accuracy of hole formation is closely related to the durability of the project. Precise hole formation ensures the smooth placement of the reinforcement cage in the designed position, guarantees the quality of concrete pouring, and forms a uniform and intact pile body structure. This effectively reduces issues such as steel corrosion and concrete cracking caused by construction defects, extending the project's service life. Conversely, insufficient hole formation accuracy may lead to difficulties in installing the reinforcement cage and result in poorly compacted concrete. Under external environmental erosion, the pile body structure gradually deteriorates, significantly shortening the project's service life and increasing future maintenance costs and safety risks.
In practical engineering, accident cases caused by insufficient hole-forming accuracy are not uncommon. In the construction of a certain high-rise building, due to the lack of experience of the rotary drilling rig operator, who failed to adjust the drilling parameters in a timely manner according to the geological conditions, the verticality deviation of some pile holes exceeded the allowable range specified by the code. During pile foundation acceptance, it was found that the bearing capacity of multiple piles did not meet the design requirements. To solve this problem, the construction unit had to carry out supplementary pile treatment for these unqualified piles, which not only delayed the project schedule but also increased the engineering cost by several million yuan additionally. Another bridge pile foundation construction accident occurred where, due to the failure to strictly control the hole diameter during hole-forming, some pile holes developed necking. During bridge operation, the pile foundation gradually developed diseases, ultimately affecting the normal use of the bridge, leading to the need for closure and maintenance, causing huge losses to society and the economy.
These cases fully demonstrate that controlling the hole-forming accuracy of the rotary drilling rig is a necessary measure to ensure engineering quality, avoid safety accidents, and reduce engineering costs. Only by attaching great importance to hole-forming accuracy during construction and strictly controlling every link from equipment selection, parameter setting, operation process to quality monitoring can the bearing capacity, stability, and durability of the pile foundation be ensured, laying a solid foundation for the smooth progress of the entire project and its long-term safe use.
1) Drilling pressure
Drilling pressure is a crucial parameter during the drilling process of rotary drilling rigs, as it directly impacts drilling efficiency and borehole wall stability. Insufficient drilling pressure prevents the drill bit from effectively cutting into the rock or soil, resulting in slow drilling progress—similar to cutting with a dull knife, which struggles to penetrate deeply. In soft soil formations, if the drilling pressure is too low, the drill bit may merely slide over the soil surface without achieving effective drilling, significantly reducing construction efficiency. Conversely, excessive drilling pressure can lead to a series of issues. On one hand, excessive pressure subjects the drill bit to undue load, accelerating wear and shortening its service life while increasing construction costs. On the other hand, excessive pressure may cause localized stress on the borehole wall, disrupting the original soil structure and triggering wall collapse, severely compromising borehole precision and construction safety.
The requirements for drilling pressure vary significantly under different geological conditions. In cohesive soil layers, where the soil exhibits certain viscosity and plasticity, the appropriate drilling pressure range typically falls between 100 and 200 kN. At this range, the drill bit can smoothly penetrate the soil without causing excessive disturbance to the borehole wall. In sandy soil layers, where the cohesive force between soil particles is relatively weak, the drilling pressure should be appropriately reduced to prevent borehole collapse, usually maintained between 50 and 100 kN. In rocky formations, due to the high hardness of the rock, a greater drilling pressure is required to break the rock, typically reaching 300 to 500 kN.
In actual construction, the drilling pressure must be adjusted flexibly based on specific conditions. When encountering strata with varying hardness, the drilling pressure should be promptly adjusted according to the formation changes. For instance, when transitioning from soft soil layers to hard soil layers, the drilling pressure should be gradually increased to ensure the drill bit can effectively break the hard soil. Conversely, when moving from hard soil layers to soft soil layers, the drilling pressure should be appropriately reduced to prevent sudden sinking of the drill bit due to excessive pressure, which could lead to hole deviation or collapse of the borehole wall. Additionally, the drilling pressure should be adjusted in conjunction with the model and performance of the drilling rig. Different models of rotary drilling rigs have variations in power systems and drill rod strength, resulting in differences in the maximum drilling pressure they can withstand. Operators must be familiar with the performance parameters of the drilling rig they are using and adjust the drilling pressure appropriately to achieve optimal drilling results while ensuring construction safety and quality.
2) Rotational Speed
Rotational speed plays a crucial role in the hole-forming process of rotary drilling rigs, significantly affecting the cutting efficiency of rock and soil and the quality of the hole wall. An appropriate rotational speed allows the drill bit to fully cut into the rock and soil, thereby improving drilling efficiency. In soft soil strata, a higher rotational speed enables the drill bit to quickly cut through the soil, reducing residual soil inside the drill bucket and enhancing slag removal efficiency, thus accelerating the drilling speed. However, excessively high rotational speed can also have negative impacts. It intensifies the friction between the drill bit and the rock/soil, generating a large amount of heat that raises the drill bit's temperature, thereby accelerating its wear. Additionally, excessively high rotational speed may cause severe vibration of the drill rod, affecting the verticality of the borehole and making the hole wall surface rough, thus reducing the hole wall quality.
Different strata require different rotational speed settings. In cohesive soil strata, due to the high viscosity of the soil, the rotational speed can be appropriately reduced, generally controlled at 10-20 r/min. This ensures the drill bit effectively cuts the soil while preventing excessive rotational speed from causing soil adhesion to the drill bit, which would affect drilling performance. In sandy soil strata, the rotational speed can be appropriately increased, typically set at 20-30 r/min, to utilize centrifugal force to fling out (fling out means 'eject' or 'throw out') sand particles from the drill bucket, improving slag removal efficiency. In rock strata, due to the high hardness of the rock, a lower rotational speed is needed to ensure the drill bit's cutting force, with a general rotational speed of 5-10 r/min.
There is a close synergistic relationship between rotational speed and drilling pressure. In actual construction, the parameters of both need to be adjusted reasonably according to the stratum conditions. When the drilling pressure is large, the rotational speed should be appropriately reduced to ensure the cutting effect and stability of the drill bit; conversely, when the drilling pressure is small, the rotational speed can be appropriately increased. When drilling in hard rock strata, using a larger drilling pressure and lower rotational speed allows the drill bit to better break the rock while avoiding excessive wear of the drill bit and borehole deviation caused by high rotational speed. When drilling in soft soil strata, combining a smaller drilling pressure with a higher rotational speed can improve drilling efficiency and ensure the flatness of the hole wall. Only by reasonably matching rotational speed and drilling pressure can efficient and precise hole-forming operations be achieved under different stratum conditions, ensuring hole-forming quality and construction progress.
3） Drilling speed
Drilling speed is one of the important factors affecting the drilling accuracy of rotary drilling rigs. If it is too fast or too slow, it will have a negative impact on the quality of drilling. If the drilling speed is too fast and the amount of rock and soil cut by the drill bit per unit time is too large, it may lead to the following problems. On the one hand, the rock and soil inside the drilling bucket cannot be effectively discharged in time, resulting in blockage of the bucket and affecting drilling efficiency. On the other hand, excessively fast drilling speed can increase the impact force of the drill bit on the hole wall, which can easily damage the stability of the hole wall and cause it to collapse. In the sand layer, the sand around the hole wall is easily disturbed during rapid drilling, losing its original stability, resulting in the collapse of the hole wall, enlarging the aperture or forming irregular shapes, which seriously affects the accuracy of drilling.
Slow drilling speed is not a good thing either. Slow drilling speed will prolong construction time and increase project costs. Meanwhile, prolonged slow drilling may cause the drill bit to repeatedly cut at the same position, causing excessive disturbance to the hole wall and reducing its stability. In addition, slow drilling speed may also cause drilling slag to accumulate in the hole, increasing the difficulty of hole cleaning and affecting subsequent processes such as steel cage placement and concrete pouring.
In order to determine a reasonable drilling speed, it is necessary to comprehensively consider factors such as geological conditions and drilling rig performance. In terms of geological conditions, the rock and soil properties of different strata are different, and the requirements for drilling speed are also different. In soft soil formations, due to the relatively soft soil, the drilling speed can be relatively fast, generally controlled at 0.5-1.5m/min. In sandy soil layers, in order to prevent the collapse of the borehole wall, the drilling speed should be appropriately reduced, usually 0.3-0.8m/min. In rock formations, due to the high hardness of the rock, the drilling speed is slow, generally ranging from 0.1-0.3m/min. When considering the performance of a drilling rig, attention should be paid to parameters such as power, torque, and lifting capacity. A drilling rig with strong power and high torque can increase the drilling speed appropriately while ensuring the quality of drilling; For drilling rigs with insufficient lifting capacity, it is necessary to control the drilling speed to avoid drilling debris falling back due to the inability to lift the drilling bucket in a timely manner, which may affect the accuracy of drilling. The operator should also adjust the drilling speed in a timely manner based on the actual drilling situation, such as the discharge of drilling slag and the performance of the mud in the hole, to ensure the smooth progress of the drilling process and the stability of the hole wall.
1） Drilling rig positioning and leveling
The accuracy and levelness of the drilling rig's positioning are important prerequisites for ensuring the accuracy of drilling. Before the drilling rig is in place, the construction site should be leveled and compacted to ensure that it can withstand the weight of the drilling rig without significant settlement. Use measuring instruments, such as total stations, to accurately determine the pile position and set clear markings at the center of the pile position.
After moving the rotary drilling rig to the vicinity of the pile position, adjust the walking mechanism and support legs of the drilling rig to align the center of the drill rod with the center of the pile position. In this process, the built-in centering system of the drilling rig can be used for preliminary centering, and then the total station can be used for verification to ensure that the centering deviation is controlled within the allowable range, generally not exceeding 50mm.
The levelness of the drilling rig has a direct impact on the verticality of the borehole. During the leveling process, a high-precision level is placed on the drilling rig chassis. By adjusting the height of the support legs, the bubble of the level is positioned at the center to ensure that the drilling rig chassis is in a horizontal state. For some rotary drilling rigs with automatic leveling function, this function can be activated to automatically adjust the rig to horizontal, but manual inspection and confirmation are still required. During the drilling process, it is also necessary to regularly check the levelness of the drilling rig to prevent it from tilting due to ground subsidence or other factors, which may affect the accuracy of drilling.
2） Techniques for burying casing
The casing plays a crucial role in the drilling process of rotary drilling machines. It not only fixes the pile position and provides guidance for drilling, but also protects the hole opening and prevents ground stones from falling into the hole. At the same time, it has multiple functions such as isolating the surface water inside and outside the hole, maintaining the mud water level and pressure to stabilize the hole wall.
When burying the casing, there are strict requirements for its depth and verticality. On the beach, the burial depth of the casing in cohesive soil and silt layers should not be less than 1m, and in sandy soil layers should not be less than 2m. When the surface soil is soft, the casing should be buried at least 0.5m in a harder and denser soil layer. When building islands in water, the casing should be buried about 1m below the riverbed surface; In seasonally frozen soil areas, the bottom of the casing should enter the unfrozen soil layer below the freezing line by no less than 0.5m. The verticality deviation of the casing should be controlled within 1% to ensure the verticality of the borehole.
The casing is usually buried by open excavation method. Firstly, use the cross method to guide the center of the pile outside the excavation area as the positioning basis for burying the casing. Then, excavate a corresponding size of foundation pit according to the diameter of the casing, and the depth of the foundation pit should be slightly deeper than the burial depth of the casing. After placing the casing into the foundation pit, use a plumb bob or total station to check the verticality of the casing. Adjust the position and verticality of the casing by backfilling clay around it and compacting it layer by layer to ensure that it is firmly buried. During the burial process, it is important to note that the deviation between the center of the casing and the center of the pile position should not exceed 50mm. After the casing is buried, it is necessary to recheck the pile position again to ensure its accuracy.
3） Drilling process control
During the drilling process, maintaining the verticality of the drill rod is the key to ensuring the accuracy of drilling. Operators should always pay attention to the verticality display device of the drilling rig, and adjust the mast angle of the drilling rig to ensure that the drill rod is always in a vertical state. At the same time, it is necessary to regularly use inclinometers to check the verticality of the borehole, usually every 3-5 meters. If the verticality deviation exceeds the allowable range (usually 1%), drilling should be stopped immediately, the cause analyzed, and corresponding corrective measures taken.
It is also very important to closely monitor the condition of the borehole wall during the drilling process. The stability of the borehole wall can be determined by observing indicators such as the color, density, and sand content of the mud, as well as changes in resistance during drilling. If the mud color suddenly darkens, the density decreases, the sand content increases, or the drilling resistance suddenly decreases, it may indicate abnormal conditions such as collapse or shrinkage of the hole wall.
Once encountering a collapsed hole, drilling should be stopped immediately and the cause of the collapse should be analyzed. If it is caused by poor mud performance, the specific gravity, viscosity, and colloid rate of the mud should be adjusted in a timely manner to improve its wall protection ability; If the drilling speed is too fast or the drilling pressure is too high, the drilling speed and drilling pressure should be appropriately reduced. For the collapsed hole area, the method of backfilling with high-quality clay or cement mortar can be used. After the backfill material is stable, re drilling can be carried out.
When the phenomenon of reducing the diameter occurs, the method of repeatedly scanning the hole up and down can be used to enlarge the aperture. During the drilling process, it is necessary to increase the specific gravity and viscosity of the mud appropriately to enhance the wall protection effect of the mud. At the same time, check the wear of the drill bit, replace the severely worn drill bit in a timely manner, and ensure that the drill bit diameter meets the design requirements.
4） Clearing holes and lowering steel cages
Clearing the hole is an important step in the drilling process of rotary drilling machines. Its purpose is to remove the sediment at the bottom of the hole, reduce the settlement of the pile foundation, and improve the bearing capacity of the pile body. Cleaning holes is generally divided into the first cleaning and the second cleaning.
The first hole cleaning is carried out after the drilling reaches the design depth. The drill bit is lifted a certain distance (usually 0.2-0.3m) from the bottom of the hole and the hole is cleaned using a positive or negative circulation method. Positive circulation hole cleaning is achieved by using a mud pump to press mud from the center of the drill pipe into the bottom of the hole, carrying sediment and flowing out of the hole; Reverse circulation cleaning is the process of extracting mud and sediment from the bottom of the borehole through equipment such as a vacuum pump, and replenishing the mud through the borehole opening. During the hole cleaning process, it is necessary to control the flow rate and velocity of the mud well to avoid disturbing the hole wall.
The second hole cleaning is carried out after the installation of the steel cage and conduit, mainly to remove new sediment that falls into the bottom of the hole during the installation process. The hole cleaning method is similar to the first time, and can choose positive circulation, reverse circulation, or gas lift reverse circulation cleaning according to the actual situation. The thickness of sediment at the bottom of the hole after cleaning should meet the design and specification requirements. For end bearing piles, it should not exceed 50mm; for friction piles, it should not exceed 100mm; and for anti pull and anti horizontal force piles, it should not exceed 200mm. At the same time, the performance indicators of the slurry should also meet the requirements. Before pouring concrete, the relative density of the slurry within 500mm of the hole bottom should be less than 1.25, the sand content should not exceed 8%, and the viscosity should not exceed 28s.
When lowering the steel cage, ensure its verticality and accurate position to avoid colliding with the hole wall. Before lifting, a sufficient number of reinforcing bars should be installed inside the steel cage to enhance its rigidity and prevent deformation during lifting and lowering. Use a crane to lift the steel cage vertically and slowly place it into the hole. During the lowering process, a guide device can be installed at the top of the steel cage to guide it smoothly and avoid scratching the hole wall. For longer steel cages, a segmented production and placement method can be used to connect them in the holes. When docking, it is necessary to ensure the quality of the main reinforcement connection, using welding or mechanical connection methods to ensure that the connection strength meets the design requirements. After the steel cage is placed in place, it should be fixed in a timely manner to prevent it from floating or sinking during the concrete pouring process.
1) Successful Case
In a large high-speed railway bridge project, rotary drilling rigs were used for hole-making in the pile foundation construction. The geological conditions of this project were complex, covering gravel layers, strongly weathered sandstone, and extremely hard rock zones. The single pile depth exceeded 80m, with a diameter of 3m, imposing extremely high requirements on hole-making accuracy.
In terms of parameter settings, the construction team demonstrated high professionalism and rigor. When drilling through the gravel layer, due to the large particle size and uneven distribution of gravel, to ensure the drill bit could effectively crush the gravel and advance smoothly, they controlled the drilling pressure between 250-350kN, set the rotational speed at 8-12r/min, and limited the drilling speed to 0.1-0.2m/min. This parameter combination allowed the drill bit to crush the gravel under sufficient pressure, while the relatively low rotational speed ensured the stability of the drill bit, avoiding excessive vibration of the drill rod caused by high speed, which could affect hole-making accuracy. The moderate drilling speed also guaranteed the stability of the hole wall.
When encountering strongly weathered sandstone, the construction team promptly adjusted the parameters based on the hardness and structural characteristics of the sandstone. The drilling pressure was adjusted to 200-250kN, the rotational speed was increased to 12-15r/min, and the drilling speed was slightly raised to 0.2-0.3m/min. Appropriately reducing the drilling pressure could avoid excessive disturbance to the hole wall, while increasing the rotational speed enabled the drill bit to utilize its cutting force more effectively to crush the sandstone and speed up the drilling process.
In the extremely hard rock zone, the construction team adopted a higher drilling pressure, controlling it at 350-500kN, reducing the speed to 5-8r/min, and further reducing the drilling speed to 0.05-0.1m/min. High drilling pressure can provide sufficient crushing force, allowing the drill bit to effectively penetrate extremely hard rocks, while low rotation speed can ensure the stability of the drill bit under high loads, preventing drill bit damage and hole inclination.
In terms of operational skills, construction personnel strictly follow the specifications for their work. When the drilling rig is in place, use a total station for precise measurement to ensure that the deviation between the center of the drilling rig and the center of the pile position is controlled within 30mm. At the same time, use a high-precision level to level the drilling rig chassis to ensure that the horizontal error of the drilling rig is within 0.5%. When burying the casing, a large vibrating hammer is used to accurately drive the casing into the ground. The burial depth of the casing reaches 3m, and the verticality deviation is controlled within 0.8%, providing good guidance and hole protection for drilling.
During the drilling process, the operator always pays attention to the verticality display device of the drilling rig and changes in drilling parameters. Every 5 meters of drilling, a inclinometer is used to detect the verticality of the borehole. Once the verticality deviation exceeds 0.8%, immediately stop drilling, analyze the cause, and make adjustments. During a drilling process, it was discovered that there was a deviation of 1.2% in verticality. Upon inspection, it was found that this was due to slight bending of the drill rod after prolonged use. The construction personnel promptly replaced the drill rod to restore verticality to normal.
The project ultimately achieved complete success, and the drilling accuracy of all pile foundations met the design and specification requirements, with a pile foundation qualification rate of 100%. This successful case fully demonstrates the crucial role of scientifically reasonable parameter settings and strictly standardized operating techniques in controlling the drilling accuracy of rotary drilling rigs, providing valuable experience and reference for similar projects.
2） Failed Cases
A high-rise building project in a certain city, with geological conditions mainly consisting of soft soil layers and the presence of sand lenses in some areas. During the drilling process of the rotary drilling rig, improper control of parameter settings and operating techniques resulted in serious issues with drilling accuracy, which in turn led to engineering quality accidents.
In terms of parameter settings, the operators did not fully consider the changes in the geological strata. In the soft soil layer, in order to pursue construction progress, the drilling pressure was set too high, reaching 250kN, and the rotation speed was set too fast, reaching 30r/min. The drilling speed was even as high as 2m/min. Excessive drilling pressure and rotational speed cause the drill bit to cut too quickly in soft soil, resulting in significant impact force and causing severe disturbance to the soil around the borehole wall, leading to collapse. When encountering a sand layer lens, the operator did not adjust the parameters in a timely manner and continued to drill according to the parameters of the soft soil layer, making it difficult for the drill bit to effectively cut in the sand layer, resulting in a sharp decrease in drilling speed. At the same time, due to the poor stability of the sand layer, the sand layer quickly collapsed under the disturbance of the drill bit, causing severe deformation of the hole wall.
There are also many mistakes in operational skills. When the drilling rig was in place, the alignment deviation reached 80mm, far exceeding the allowable range, and the horizontal adjustment was not in place, resulting in a tendency for the drilling rig to tilt during the drilling process. When burying the casing, the depth was only 1m, which did not meet the standard requirement of 2m, and the verticality deviation reached 3%, making it unable to provide effective guidance and hole protection for the borehole. During the drilling process, the operators did not closely monitor the situation inside the hole and did not promptly detect issues such as collapse of the hole wall and abnormal sand layers. They only stopped drilling after serious deviation and shrinkage of the borehole, which had already caused irreparable losses.
These problems have led to serious non-compliance with the drilling accuracy of some pile foundations, with a vertical deviation of over 5% for the pile body, a hole diameter deviation of 20% of the design value, and a sediment thickness at the bottom of the pile exceeding 300mm, far exceeding the allowable range of the specifications. After testing, it was found that the bearing capacity of multiple piles could not meet the design requirements and had to be reworked. During the rework process, it is necessary to break down the unqualified piles and perform drilling and grouting operations again. This not only consumes a lot of manpower, material resources, and time, resulting in a delay of 3 months in the project schedule, but also increases the project cost by more than 5 million yuan.
We can learn a profound lesson from this failed case. In the drilling process of rotary drilling machines, it is necessary to adjust parameters in a timely and accurate manner according to changes in geological conditions, strictly follow the requirements of the specifications, strengthen monitoring and management of the construction process, and ensure that every link meets quality standards. Only in this way can we effectively avoid the occurrence of drilling accuracy problems and ensure the quality and progress of the project.
The precision control of rotary drilling rig drilling is a systematic and critical task, with parameter settings and operational skills being the core elements. Parameters such as drilling pressure, rotational speed, and drilling speed need to be precisely adjusted according to different geological conditions. They are interrelated and jointly affect the quality and efficiency of drilling. Appropriate drilling pressure can ensure effective cutting of rock and soil by the drill bit. The rotational speed affects the cutting effect and the quality of the hole wall, while the drilling speed is related to the stability of the hole wall.
In terms of operational skills, the accuracy of drilling rig positioning and leveling, the standardization of casing burial, the fine control of drilling process, and the strict operation of hole cleaning and steel cage placement must not be compromised at any stage. Accurate alignment and horizontal adjustment of the drilling rig during positioning lay the foundation for the verticality of the borehole; The depth and verticality of the buried casing directly affect the guidance of the borehole and the safety of the hole opening; Close monitoring of the verticality of the drill pipe and the condition of the hole wall during the drilling process, timely detection and resolution of problems, is the key to ensuring the accuracy of drilling; The thoroughness of hole cleaning and the accuracy of steel cage placement are related to the bearing capacity and stability of the pile foundation.
Successful cases have shown that the scientific and rational use of parameter settings and operational techniques can achieve high-precision drilling operations, ensuring the smooth progress and high-quality completion of projects. And failure cases serve as a warning to us that any negligence in any aspect can lead to serious consequences, not only delaying the construction period but also significantly increasing the project cost.
Looking ahead to the future, with the continuous advancement of technology, rotary drilling rig technology will inevitably usher in a new stage of development. The application of intelligent technology will enable rotary drilling rigs to monitor and automatically adjust drilling parameters in real time, further improving drilling accuracy and construction efficiency. Through sensors and intelligent control systems, the drilling rig can automatically optimize parameters such as drilling pressure, speed, and drilling speed based on changes in geological conditions, achieving more accurate drilling operations. At the same time, automated operations will also reduce the impact of human factors on drilling accuracy, lower labor intensity, and improve construction safety and reliability.
The development of materials science will also bring more advanced drill bits and drill rod materials to rotary drilling rigs. These new materials will have higher strength, wear resistance, and corrosion resistance, which can better adapt to complex geological conditions, reduce equipment failures, extend equipment service life, and indirectly improve drilling accuracy. With the increasing demand for environmental protection, rotary drilling rigs will also develop towards green environmental protection, adopting more environmentally friendly power systems and construction processes to reduce their impact on the environment and achieve coordinated development between engineering construction and environmental protection.
In future engineering construction, the precision control technology of rotary drilling machines will continue to innovate and improve, providing a more solid and reliable foundation for the construction of various large-scale projects, and promoting the entire engineering construction industry to move towards higher quality, more efficient, and more environmentally friendly directions.
