Method for evaluating surrounding rock properties while drilling

Abstract

An embodiment of the present invention provides a method for evaluating the performance of surrounding rock during drilling. The method includes the following steps: obtaining the range of drilling parameters when the drill rig drills in rock formations with different lithologies in the surrounding rock; using the drill rig to drill holes in the surrounding rock of the roadway and obtaining the drilling parameters of the drill rig; comparing the obtained drilling parameters with the range of drilling parameters to obtain the rock formations contained in the surrounding rock and the fracture parameters of the surrounding rock; obtaining the RQD value of the surrounding rock of the roadway according to the fracture parameters; comparing the RQD value of the surrounding rock of the roadway with the RQD values in the RQD classification table to obtain the stability level of the surrounding rock of the roadway. The method for evaluating the performance of surrounding rock during drilling according to the embodiment of the present invention is simple and convenient, can effectively evaluate the stability of the surrounding rock of the roadway, and enables the staff to timely adjust the roadway excavation and support process and the support scheme according to the stability of the surrounding rock of the roadway.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnels, and in particular to a method for evaluating surrounding rock properties while drilling. Background Art

[0002] Under the action of in-situ stress, tunnel surrounding rock can deform and fail, causing delamination and leading to tunnel instability or significant deformation. Tunnel anchor support is an important means of ensuring tunnel surrounding rock stability, and the support design depends on the surrounding rock properties.

[0003] In related technologies, core drilling is performed using a core drill. The length of the complete columnar core is measured and compared with the drilled length to calculate the RQD value of the roadway surrounding rock. The calculated RQD value is then compared with the RQD classification table to evaluate the surrounding rock performance and serve as a basis for support design.

[0004] However, obtaining columnar cores using a coring drill is a cumbersome operation requiring separate, large-diameter coring equipment. The process involves drilling with the drill rod, withdrawing the rod to obtain the core, preserving the core, and continuing drilling and coring. Drilling a 7-meter-long core can take several hours, which is time-consuming. Coring is typically performed at one or two representative locations near the roadway to be excavated, serving as a basis for designing support for the entire roadway. However, underground roadways often exceed 1,000 meters in length, sometimes even reaching 6,000 meters. The mechanical properties of the surrounding rock vary considerably, making support design using the aforementioned method difficult to meet the requirements for controlling the stability of the surrounding rock along the entire length of the roadway. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention provides a method for evaluating surrounding rock properties while drilling, which can effectively evaluate the stability of tunnel surrounding rock.

[0006] The method for evaluating surrounding rock properties while drilling according to an embodiment of the present invention includes the following steps:

[0007] S10, obtaining a drilling parameter range for drilling holes in rock formations of different lithologies in the surrounding rock;

[0008] S20, drilling a hole in the surrounding rock of the tunnel using a drilling rig, and obtaining drilling parameters of the drilling rig;

[0009] S30, comparing the drilling parameters obtained in step S20 with the drilling parameter range in step S10 to obtain the rock layers included in the surrounding rock and the fracture parameters of the surrounding rock;

[0010] S40, obtaining the RQD value of the tunnel surrounding rock according to the fracture parameter;

[0011] S50. Compare the RQD value of the surrounding rock of the roadway with the RQD values in the RQD classification table to obtain the stability level of the surrounding rock of the roadway.

[0012] In some embodiments, in the steps S10 and S20, the drilling parameters include at least one of drilling speed, drilling thrust, drill rig water pressure, drill rig water loss, drill rig torque, and drill rig rotation speed.

[0013] In some embodiments, in the step S20, when there is at least one water pressure mutation of the drill rig water pressure, and / or at least one water loss mutation of the drill rig water loss, and / or at least one torque mutation of the drill rig torque, and / or at least one rotation speed mutation of the drill rig rotation speed;

[0014] Among them, the water pressure mutation is divided into a sudden drop in water pressure and a sudden increase in water pressure, the water loss mutation is divided into a sudden drop in water loss and a sudden increase in water loss, the torque mutation is divided into a sudden drop in torque and a sudden increase in torque, and the rotation speed mutation is divided into a sudden drop in rotation speed and a sudden increase in rotation speed. When there is a sudden drop in water pressure and / or a sudden increase in water loss and / or a sudden drop in torque and / or a sudden increase in rotation speed of the drill rig, it is determined that there are fissures in the surrounding rock of the roadway at the position where the sudden drop in water pressure and / or the sudden increase in water loss and / or the sudden drop in torque and / or the sudden increase in rotation speed of the drill rig occurs.

[0015] In some embodiments, in the step S30, the fissure parameters include at least one of fissure aperture, fissure position, and fissure area.

[0016] In some embodiments, in the step S20, the drill rig is used to drill holes at different positions of the surrounding rock of the roadway, and the drilling parameters of the drill rig are obtained during each drilling process.

[0017] In the step S30, it is determined whether there are fissures in the surrounding rock of the roadway according to the drilling parameters, and the fissure area of the surrounding rock of the roadway is obtained.

[0018] In some embodiments, in the step S20, obtain the initial time point when the drill rig starts drilling, the first drilling time point when the drill rig drills to the fissure, and the drilling speed of the drill rig.

[0019] In the step S30, according to the initial time point, the first drilling time point, and the drilling speed, obtain the fissure position.

[0020] Among them, the fissure position is equal to the product of the first drilling duration and the drilling speed, and the first drilling duration is equal to the difference between the first drilling time point and the initial time point.

[0021] In some embodiments, in step S20, obtain the second drilling time point when the drill rig drills to the crack, the third drilling time point when the drill rig drills out of the crack, and the drilling speed of the drill rig;

[0022] In step S30, obtain the crack aperture according to the second drilling time point, the third drilling time point, and the drilling speed;

[0023] Wherein, the crack aperture is equal to the product of the second drilling duration and the drilling speed, and the second drilling duration is equal to the difference between the third drilling time point and the second drilling time point.

[0024] In some embodiments, in step S20, obtain the time point when the water pressure of the drill rig drops suddenly and the time point when the water pressure of the drill rig rises suddenly next time within the same time period, the time point when the water loss suddenly increases and the time point when the water loss of the drill rig drops suddenly next time, the time point when the torque of the drill rig drops suddenly and the time point when the torque of the drill rig increases suddenly next time, and the time point when the rotational speed of the drill rig increases suddenly and the time point when the rotational speed of the drill rig drops suddenly next time;

[0025] In step S30, the second drilling time point is equal to the average value of the time point when the water pressure of the drill rig drops suddenly, the time point when the water loss suddenly increases, the time point when the torque of the drill rig drops suddenly, and the time point when the rotational speed of the drill rig increases suddenly, and the third drilling time point is equal to the average value of the time point when the water pressure of the drill rig rises suddenly, the time point when the water loss of the drill rig drops suddenly, the time point when the torque of the drill rig increases suddenly, and the time point when the rotational speed of the drill rig drops suddenly.

[0026] In some embodiments, in step S50,

[0027] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 0% - 25%, the stability level of the roadway surrounding rock is very poor;

[0028] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 25% - 50%, the stability level of the roadway surrounding rock is poor;

[0029] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 50% - 75%, the stability level of the roadway surrounding rock is average;

[0030] When the ratio of the RQD value of the surrounding rock of the roadway to the RQD value in the RQD classification table is 75%-90%, the stability level of the surrounding rock of the roadway is good;

[0031] The in-situ evaluation method for surrounding rock properties further includes step S60. When the stability level is very bad or bad, first reinforce the surrounding rock of the roadway with anchor cables, and then perform the next drilling operation. Brief Description of the Drawings

[0032] Figure 1 is a schematic diagram of the drilling of the drill rig in the in-situ evaluation method for surrounding rock properties of an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of determining the types of rock formations in the surrounding rock based on rock samples in the in-situ evaluation method for surrounding rock properties of an embodiment of the present invention. Detailed Embodiments

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0035] The in-situ evaluation method for surrounding rock properties of an embodiment of the present invention will be described in detail below.

[0036] An in-situ evaluation method for surrounding rock properties of an embodiment of the present invention includes the following steps:

[0037] S10, obtaining the range of drilling parameters of the drill rig when drilling in rock formations with different lithologies in the surrounding rock;

[0038] S20, using the drill rig to drill holes in the surrounding rock of the roadway and obtaining the drilling parameters of the drill rig;

[0039] S30, comparing the drilling parameters obtained in step S20 with the range of drilling parameters in step S10 to obtain the rock formations included in the surrounding rock and the fracture parameters of the surrounding rock;

[0040] S40, obtaining the RQD value of the surrounding rock of the roadway according to the fracture parameters;

[0041] S50, comparing the RQD value of the surrounding rock of the roadway with the RQD value in the RQD classification table to obtain the stability level of the surrounding rock of the roadway.

[0042] The method for evaluating the surrounding rock performance during drilling according to the embodiment of the present invention first obtains the range of drilling parameters during the drilling process of the drill rig in rock formations with different lithologies in the surrounding rock, and uses the range of drilling parameters as the standard value, so that during the subsequent drilling of the surrounding rock, the staff can compare the drilling parameters of the drill rig with the standard value in real time, and then obtain the rock formation where the drill rig is located in real time. It can be understood that the worker can compare the drilling parameters of the drill rig with the standard value of the drill rig in real time, and then obtain the types of rock formations at different positions during the drilling process of the drill rig. It can be imagined that since the drill rig parameters in the fissure also have a certain range, the fissure can also be understood as a rock formation with special "lithology", such as Figure 2 as shown. Thus, the fissure parameters in the surrounding rock can be obtained by obtaining the drilling parameters during the drilling process of the drill rig in real time and comparing them with the standard value. The RQD value of the surrounding rock is obtained through the fissure parameters, and then the stability level of the surrounding rock is obtained, thereby completing the evaluation of the surrounding rock performance.

[0043] Therefore, the method for evaluating the surrounding rock performance during drilling according to the embodiment of the present invention only needs to obtain the drilling parameters during the drilling process of the drill rig, and then through simple comparative analysis and calculation, it can be obtained whether there are fissures in the roadway surrounding rock, and the fissure parameters existing in the roadway surrounding rock can also be obtained. Then, according to the fissure parameters, the RQD value of the roadway surrounding rock can be obtained, and the RQD value of the roadway surrounding rock is compared with the RQD classification value, and then the stability level of the roadway surrounding rock is obtained, so as to achieve the effect of evaluating the stability of the roadway surrounding rock. Compared with the method of measuring columnar rock cores in the related art, the method for evaluating the surrounding rock performance during drilling provided by the embodiment of the present invention is simpler and more convenient.

[0044] Therefore, the method for evaluating the surrounding rock performance during drilling according to the embodiment of the present invention has the characteristics of simplicity and convenience, and can effectively evaluate the stability of the roadway surrounding rock, enabling the staff to adjust the roadway excavation and support technology and support plan in time according to the stability of the roadway surrounding rock.

[0045] In some embodiments, in step S10, first, samples of rock formations with different lithologies in the surrounding rock are obtained and marked as rock 1, rock 2, rock 3... rock N;

[0046] The drill rig is used to drill the rock formation samples of rock 1, rock 2, rock 3... rock N respectively for multiple times, and the range of drilling parameters of the drill rig when drilling on the rock formation samples with different lithologies is obtained, and marked as rock 1 range, rock 2 range, rock 3 range... rock N range.

[0047] Since the types of rock formations with different lithologies included in the roadway surrounding rock in a single area can be basically determined, rock formations with different lithologies can be collected as samples in the surrounding rock first. Use a drill rig to drill multiple holes in the rock formations with different lithologies respectively to obtain the range of drilling parameters when the drill rig drills in different rock formations. It can be understood that the determination of the range of drilling parameters can use the drill rig to drill multiple holes in the same rock formation sample to obtain multiple sets of drilling parameter values. Among them, the number of drilling holes for the same rock formation sample should be as many as possible to form a database of drilling parameters for this rock formation sample. By analyzing the database of drilling parameters for this rock formation sample, the range of drilling parameters for this rock formation sample can be obtained, which can greatly improve the accuracy of the range of drilling parameters and also provide better data support for the subsequent evaluation of the surrounding rock performance.

[0048] In some embodiments, in step S50,

[0049] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 0% - 25%, the stability level of the roadway surrounding rock is very poor.

[0050] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 25% - 50%, the stability level of the roadway surrounding rock is poor.

[0051] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 50% - 75%, the stability level of the roadway surrounding rock is average.

[0052] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 75% - 90%, the stability level of the roadway surrounding rock is good.

[0053] When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 90% - 100%, the stability level of the roadway surrounding rock is very good.

[0054] In some embodiments, it further includes step S60. When the stability level is very poor and poor, first use anchor cables to reinforce the roadway surrounding rock, and then perform the next drilling operation.

[0055] The in - situ evaluation method for surrounding rock performance according to the embodiments of the present invention obtains rock formation type samples of the surrounding rock in the area where it is located, and uses a drilling rig to obtain drilling parameters in different types of rock formations as standard values. Therefore, during the process of drilling in the surrounding rock borehole, the drilling parameters of the drilling rig during the drilling process can be obtained in real - time and compared with the standard values, thereby obtaining the type of rock formation and the fracture parameters of the fractures in the surrounding rock, and further obtaining the fracture parameters to calculate the RQD value of the roadway surrounding rock. The RQD value of the roadway surrounding rock is compared with the RQD classification table to obtain the stability level of the roadway surrounding rock. For some positions with poor stability, the cable bolts are used to reinforce these positions in a timely manner to minimize the risk of accidents. Thus, the in - situ evaluation method for surrounding rock performance according to the embodiments of the present invention can effectively evaluate the stability of the roadway surrounding rock.

[0056] In some embodiments, in steps S10 and S20, the drilling parameters include at least one of the drilling speed, drilling thrust, drilling rig water pressure, drilling rig water loss, drilling rig torque, and drilling rig rotation speed.

[0057] Further, in step S20, when there is at least one water pressure mutation in the drilling rig water pressure, and / or at least one water loss mutation in the drilling rig water loss, and / or at least one torque mutation in the drilling rig torque, and / or at least one rotation speed mutation in the drilling rig rotation speed, when there is a sudden drop in the drilling rig water pressure and / or a sudden increase in the drilling rig water loss and / or a sudden drop in the drilling rig torque and / or a sudden increase in the drilling rig rotation speed, it is determined that there are fractures in the surrounding rock of the roadway at the position where the sudden drop in the drilling rig water pressure and / or the sudden increase in the drilling rig water loss and / or the sudden drop in the drilling rig torque and / or the sudden increase in the drilling rig rotation speed occurs.

[0058] Among them, the water pressure mutation is divided into a sudden drop in water pressure and a sudden increase in water pressure, the water loss mutation is divided into a sudden drop in water loss and a sudden increase in water loss, the torque mutation is divided into a sudden drop in torque and a sudden increase in torque, and the rotation speed mutation is divided into a sudden drop in rotation speed and a sudden increase in rotation speed.

[0059] Since during the drilling process of the drilling rig, if there are fractures in the surrounding rock of the roadway, then the drilling rig water pressure, the drilling rig water loss, the drilling rig torque, and the drilling rig rotation speed will all mutate. By using the mutations of the drilling rig water pressure, the drilling rig water loss, the drilling rig torque, and the drilling rig rotation speed to judge whether there are fractures in the surrounding rock of the roadway, the judgment accuracy is higher, and when the drilling parameters of the drilling rig change, the staff can more intuitively and quickly obtain whether there are fractures in the surrounding rock of the roadway.

[0060] It can be understood that during the drilling process of the drilling rig, when the drilling rig water pressure, the drilling rig water loss, the drilling rig torque, and the drilling rig rotation speed change periodically or regularly, it can be judged that there are no fractures at the position where the drilling rig is drilling.

[0061] In some embodiments, in step S30, the fracture parameters include at least one of the fracture aperture, fracture position, and fracture area.

[0062] The fracture parameters include at least one of the fracture aperture, fracture position, and fracture area, which can be understood as: the fracture parameters include one of the fracture aperture, fracture position, and fracture area; or, the fracture parameters include two of the fracture aperture, fracture position, and fracture area; or, the fracture parameters include each of the fracture aperture, fracture position, and fracture area.

[0063] Among them, the fracture area refers to the size of the fracture area, the fracture aperture refers to the dimension of the fracture in the drilling direction of the drill rig, and the fracture position refers to the depth of the fracture in the surrounding rock of the roadway.

[0064] By obtaining at least one of the fracture aperture, fracture position, and fracture area, the stability of the surrounding rock of the roadway can be judged more intuitively and accurately according to the fracture parameters, making the judgment of the stability level of the surrounding rock of the roadway more accurate.

[0065] In some embodiments, in step S20, the drill rig is used to drill holes at different positions of the surrounding rock of the roadway, and the drilling parameters of the drill rig are obtained during each drilling process;

[0066] In step S30, it is judged whether there are fractures in the surrounding rock of the roadway according to the drilling parameters, and the fracture area of the surrounding rock of the roadway is obtained.

[0067] In step S20, when one of the situations of sudden drop in water pressure, sudden drop in torque, sudden increase in water loss, and sudden increase in rotational speed occurs to the drill rig, it can be determined that there are fractures in the surrounding rock of the roadway. It can be understood that when multiple situations of sudden drop in water pressure, sudden drop in torque, sudden increase in water loss, and sudden increase in rotational speed occur to the drill rig, it can also be determined that there are fractures in the surrounding rock of the roadway.

[0068] Using the drill rig to drill holes at different positions of the surrounding rock of the roadway, it is possible to judge whether there are fractures at the position of any drilled hole by analyzing the drilling parameters of the drill rig. The drilled holes where fractures are determined can be connected in sequence to form a measurement plane, and then the fracture area of the surrounding rock of the roadway can be determined.

[0069] At the same time, the number of fractures can be determined according to the change of the drilling parameters. For example, during the drilling process of the drill rig, when one or more of the situations of sudden drop in water pressure, sudden drop in torque, sudden increase in water loss, and sudden increase in rotational speed occur within the same time period, it is determined that there are fractures. At the same time, the number of fractures can also be determined according to the number of the above-mentioned situations occurring during the drilling process.

[0070] The evaluation method for the performance of the surrounding rock during drilling according to the embodiments of the present invention enables the staff to better judge whether there are fractures at the position of the drilled hole by obtaining the drilling parameters of the drill rig, and then obtain the size of the fractures, so as to evaluate the stability of the surrounding rock of the roadway. Therefore, the staff can effectively evaluate the stability of the surrounding rock of the roadway.

[0071] In some embodiments, in step S20, obtain the initial time point when the drill starts drilling, the first drilling time point when the drill reaches the fracture, and the drilling speed of the drill;

[0072] In step S30, obtain the fracture position according to the initial time point, the first drilling time point, and the drilling speed;

[0073] Wherein, the fracture position is equal to the product of the first drilling duration and the drilling speed, and the first drilling duration is equal to the difference between the first drilling time point and the initial time point.

[0074] The evaluation method for surrounding rock performance during drilling according to the embodiments of the present invention enables the staff to better determine the fracture position in the roadway surrounding rock by obtaining the drilling parameters of the drill, and thus can better evaluate the stability of the roadway surrounding rock. Therefore, the evaluation method for the stability of the roadway surrounding rock according to the embodiments of the present invention can effectively evaluate the stability of the roadway surrounding rock.

[0075] In some embodiments, in step S20, obtain the second drilling time point when the drill reaches the fracture, the third drilling time point when the drill exits the fracture, and the drilling speed of the drill;

[0076] In step S30, obtain the fracture aperture according to the second drilling time point, the third drilling time point, and the drilling speed;

[0077] Wherein, the fracture aperture is equal to the product of the second drilling duration and the drilling speed, and the second drilling duration is equal to the difference between the third drilling time point and the second drilling time point.

[0078] The evaluation method for surrounding rock performance during drilling according to the embodiments of the present invention enables the staff to better determine the fracture aperture in the roadway surrounding rock by obtaining the drilling parameters of the drill, and thus can better evaluate the stability of the roadway surrounding rock. Therefore, the evaluation method for the stability of the roadway surrounding rock according to the embodiments of the present invention can effectively evaluate the stability of the roadway surrounding rock.

[0079] In some embodiments, in step S20, obtain the time point when the water pressure of the drill suddenly drops and the time point when the water pressure of the drill suddenly rises next time within the same time period, the time point when the water loss suddenly increases and the time point when the water loss of the drill suddenly drops next time, the time point when the torque of the drill suddenly drops and the time point when the torque of the drill suddenly increases next time, and the time point when the rotational speed of the drill suddenly increases and the time point when the rotational speed of the drill suddenly drops next time.

[0080] It should be noted that when there are multiple fissures in the surrounding rock of the roadway, the drilling parameters of the drill will mutate multiple times during the drilling process, and the drilling parameters will simultaneously experience sudden changes in water pressure, sudden changes in water loss, sudden changes in drill torque, and sudden changes in drill speed due to the same fissure. The sudden changes in water pressure, sudden changes in water flow vector, sudden changes in drill torque, and sudden changes in drill speed caused by the same fissure all occur within the same time period. By obtaining the time points of sudden drops and sudden increases in drill water pressure, sudden increases and sudden drops in water loss, sudden drops and sudden increases in drill torque, and sudden increases and sudden drops in drill speed within the same time period, it is possible to obtain the time point of sudden drop in water pressure caused by the same fissure and the time point of the next sudden increase in drill water pressure, the time point of sudden increase in water loss and the time point of the next sudden drop in water loss of the drill, the time point of sudden drop in drill torque and the time point of the next sudden increase in drill torque, and the time point of sudden increase in drill speed and the time point of the next sudden drop in drill speed.

[0081] In step S30, the second drilling time point is equal to the average value of the time points of sudden drops in drill water pressure, sudden increases in water loss, sudden drops in drill torque, and sudden increases in drill speed, and the third drilling time point is equal to the average value of the time points of sudden increases in drill water pressure, sudden drops in water loss, sudden increases in drill torque, and sudden drops in drill speed.

[0082] By taking the average value of the time points of sudden drops in drill water pressure, sudden increases in water loss, sudden drops in drill torque, and sudden increases in drill speed as the second drilling time point, and taking the average value of the time points of sudden increases in drill water pressure, sudden drops in water loss, sudden increases in drill torque, and sudden drops in drill speed as the third drilling time point, the time point when the drill reaches the fissure is made more accurate, and thus the result of the staff analyzing the fissure opening is made more accurate, and the stability evaluation of the surrounding rock of the roadway is more accurate.

[0083] In some embodiments, when analyzing the drilling parameters, the drilling parameters can be processed through a neural network algorithm and a relevant weight matrix to prevent the state of abnormal mutation of the drilling parameters from being determined as the existence of a fissure, so that the method for evaluating the performance of the surrounding rock during drilling according to the embodiments of the present invention can more accurately evaluate the stability of the surrounding rock of the roadway.

[0084] The surrounding rock performance evaluation method according to the embodiments of the present invention can obtain fracture parameters during the drilling process of the drilling rig, evaluate the fractures in the prepared surrounding rock before the roadway excavation, and be used as the basis for the support design. It can also be dynamically measured in a timely manner during the tunneling - support process to continuously monitor the performance of the surrounding rock with a certain thickness of the roof and two sides along the entire length of the roadway, so as to achieve the effect of safe tunneling in the roadway.

[0085] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0086] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "plural" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0087] In the present invention, unless otherwise clearly specified and limited, the terms such as "install", "connect", "connection", "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0088] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0089] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0090] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for evaluating surrounding rock properties while drilling, characterized in that: The steps include: S10, obtaining a drilling parameter range for drilling holes in rock formations of different lithologies in the surrounding rock; S20, drilling a hole in the surrounding rock of the tunnel using a drilling rig, and obtaining drilling parameters of the drilling rig; S30, comparing the drilling parameters obtained in step S20 with the drilling parameter range in step S10 to obtain the rock layers included in the surrounding rock and the fracture parameters of the surrounding rock; S40, obtaining the RQD value of the tunnel surrounding rock according to the fracture parameter; S50, comparing the RQD value of the roadway surrounding rock with the RQD value in the RQD classification table to obtain the stability level of the roadway surrounding rock; In step S10 and step S20, the drilling parameters include at least one of drilling speed, drilling thrust, drilling rig water pressure, drilling rig water loss, drilling rig torque, and drilling rig rotational speed. In step S20, when the drilling rig water pressure undergoes at least one sudden change in pressure, and / or the drilling rig water loss undergoes at least one sudden change in water loss, and / or the drilling rig torque undergoes at least one sudden change in torque, and / or the drilling rig rotational speed undergoes at least one sudden change in rotational speed; The water pressure mutation is divided into a sudden drop in water pressure and a sudden increase in water pressure, the water loss mutation is divided into a sudden drop in water loss and a sudden increase in water loss, the torque mutation is divided into a sudden drop in torque and a sudden increase in torque, and the speed mutation is divided into a sudden drop in speed and a sudden increase in speed. When the drilling rig experiences a sudden drop in water pressure and / or a sudden increase in water loss and / or a sudden drop in torque and / or a sudden increase in speed, it is determined that cracks exist in the surrounding rock of the tunnel at the location where the drilling rig experiences a sudden drop in water pressure and / or a sudden increase in water loss and / or a sudden drop in torque and / or a sudden increase in speed. In step S20, the time point at which the water pressure of the drilling rig suddenly drops and the time point at which the water pressure of the drilling rig suddenly rises next time, the time point at which the water loss suddenly increases and the time point at which the water loss suddenly drops next time, the time point at which the torque of the drilling rig suddenly drops and the time point at which the torque of the drilling rig suddenly increases next time, and the time point at which the speed of the drilling rig suddenly increases and the time point at which the speed of the drilling rig suddenly drops next time are obtained within the same time period; In step S20, the initial time point when the drill starts drilling, the first drilling time point when the drill reaches the fissure, the second drilling time point when the drill exits the fissure, and the drilling speed of the drill are obtained. In step S30, the second drilling time point is equal to the average of the time point at which the drilling rig water pressure experiences the water pressure drop, the time point at which the water loss experiences the water loss increase, the time point at which the drilling rig torque experiences the torque drop, and the time point at which the drilling rig speed experiences the speed increase, and the third drilling time point is equal to the average of the time point at which the drilling rig water pressure experiences the water pressure increase, the time point at which the water loss experiences the water loss drop, the time point at which the drilling rig torque experiences the torque increase, and the time point at which the drilling rig speed experiences the speed drop.

2. The method for evaluating surrounding rock properties while drilling according to claim 1, characterized in that: In step S10, firstly, samples of rock layers of different lithologies in the surrounding rock are obtained and marked as rock 1, rock 2, rock 3, ... rock N; A drilling rig is used to drill multiple holes in rock samples of rock 1, rock 2, rock 3...rock N, and the drilling parameter ranges of the drilling rig on rock samples of different lithologies are obtained, which are marked as rock 1 range, rock 2 range, rock 3 range...rock N range.

3. The method for evaluating surrounding rock properties while drilling according to claim 1, characterized in that: In the step S30, the crack parameters include at least one of crack opening, crack position and crack area.

4. The method for evaluating surrounding rock properties while drilling according to claim 3, characterized in that: In step S10, a drilling rig is used to drill holes at different positions of the surrounding rock of the tunnel, and drilling parameters of the drilling rig are obtained during each drilling process; In the step S30, whether there are cracks in the surrounding rock of the tunnel is determined according to the drilling parameters, and the crack area of the surrounding rock of the tunnel is obtained.

5. The method for evaluating surrounding rock properties while drilling according to claim 3, characterized in that: In the step S30, the crack position is obtained according to the initial time point, the first drilling time point and the drilling speed; The crack position is equal to the product of the first drilling time and the drilling speed, and the first drilling time is equal to the difference between the first drilling time point and the initial time point.

6. The method for evaluating surrounding rock properties while drilling according to claim 3, characterized in that: In the step S30, the fracture aperture is obtained according to the second drilling time point, the third drilling time point and the drilling speed; The fracture aperture is equal to the product of the second drilling time and the drilling speed, and the second drilling time is equal to the difference between the third drilling time point and the second drilling time point.

7. The method for evaluating surrounding rock properties while drilling according to claim 1, characterized in that: In the step S50, When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 0%-25%, the stability level of the roadway surrounding rock is very bad; When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 25%-50%, the stability level of the roadway surrounding rock is bad; When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 50%-75%, the stability level of the roadway surrounding rock is general; When the ratio of the RQD value of the roadway surrounding rock to the RQD value in the RQD classification table is 75%-90%, the stability level of the roadway surrounding rock is good; The method further includes step S60 , in which, when the stability level is very bad or bad, anchor cables are first used to reinforce the surrounding rock of the tunnel before the next drilling operation is performed.

Images