A kind of hard rock pile foundation construction technology

Abstract

The present application relates to the field of pile foundations, and specifically discloses a hard rock pile foundation construction process, which includes the following steps: S1. pile foundation protection; S2. soil layer drilling; S3. inclined rock surface detection, collecting vertical displacement data when the probe rod moves around the inner wall of the steel casing; S4. inclined rock surface data simulation, setting the point when the probe rod is lowered to the inclined rock surface as the origin, and drawing a coordinate diagram for displaying the inclined rock surface angular curve with the rotation angle of the probe rod along the inner wall of the steel casing as the horizontal coordinate and the movement stroke of the probe rod in the vertical direction as the vertical coordinate; S5. inclined rock layer cutting, lowering the milling drill bit, and according to the inclined rock surface angular curve in step S4, milling out an arc groove along the inner wall of the steel casing at the top of the slope of the inclined rock layer in the form of layer-by-layer exploration; S6. hole forming, lowering the cone hollow barrel drill and embedding it in the arc groove, drilling into the bearing layer of the designed elevation through the cone hollow barrel, and taking the rock core; S7. pile forming. The present invention has the effect of preventing eccentricity when drilling through a slope rock surface.

Description

Technical Field

[0001] The present application relates to the field of pile foundation construction, and in particular to a hard rock stratum pile foundation construction process. Background Art

[0002] Bored piles are the most basic form of bridge construction and are frequently used in railway and highway projects. Bored piles are typically constructed underground or underwater, where geological conditions are complex and diverse, making it difficult to fully understand them. During construction, complex geological conditions, such as rock formations or karst caves, often arise. When encountering hard, sloping rock, conventional drill bits must be replaced with cone-type hollow barrel drills to drill into the hard rock to form a core, which is then twisted off and extracted from the pile hole. However, cone-type hollow barrel drills can easily cause eccentricity in the sloping rock due to uneven circumferential force applied to the drill bit, making drilling construction relatively difficult.

[0003] In the related art, a Chinese patent with publication number CN110410001A proposes a construction method for pile foundation drilling in super-hard rock formations, which includes the following steps: Step 1: Use an excavator to dig a casing foundation pit, bury a steel casing in the center and reinforce it; Step 2: Use an impact drill to perform impact drilling in a special formation; Step 3: After the drilling of the special formation is completed and the rubble or pebbles used for auxiliary drilling have been completely crushed, the drill bit is removed, the rotary drill is replaced, and the reverse circulation construction process is used to continue drilling until the hole is formed; when the steel casing is buried in the center in step 1, clay is backfilled in layers around the steel casing and compacted; in soft geological conditions, cement soil or plain concrete is used for reinforcement.

[0004] Regarding the above-mentioned related technologies, when using an impact drill to impact drill a slope rock formation, the guiding effect of the slope of the rock formation on the impact drill can easily change the impact direction, thereby causing the pile hole to expand at the slope rock surface, and also causing serious pile hole eccentricity, which is not conducive to the normal construction of the pile foundation in the rock formation. Summary of the Invention

[0005] In order to improve the problem of drilling eccentricity that pile foundations are prone to occur during construction on sloping rock surfaces, the present application provides a hard rock stratum pile foundation construction process.

[0006] The present application provides a hard rock pile foundation construction process that adopts the following technical solutions:

[0007] A hard rock stratum pile foundation construction process comprises the following steps:

[0008] S1. Pile foundation protection: dig a casing pit at the construction site, bury the steel casing in the center and reinforce it;

[0009] S2 soil drilling, using the rotary drilling rig drill bit drilled in the steel casing to the top of the inclined rock formation, stop drilling;

[0010] S3 inclined rock surface detection, the steel casing lowered vertically set and vertically movable probe, collecting the probe around the inner wall of the steel casing when the vertical displacement data;

[0011] S4. Simulate the inclined rock surface data. The point where the probe rod is lowered into contact with the inclined rock formation is defined as the origin. A coordinate graph is drawn to illustrate the angular position curve of the inclined rock surface, with the rotation angle of the probe rod along the inner wall of the steel casing as the abscissa and the vertical travel of the probe rod as the ordinate.

[0012] S5. Cutting the inclined rock formation, lowering the milling drill bit that can move circumferentially around the inner wall of the steel casing, and milling out an arc groove along the inner wall of the steel casing at the top of the slope of the inclined rock formation in the form of layer-by-layer exploration according to the inclined rock surface angle curve in step S4;

[0013] S6. Drilling, lowering the cone hollow cylinder drill and embedding the cone hollow cylinder into the arc groove, drilling into the design elevation bearing layer through the cone hollow cylinder, and taking the core;

[0014] S7. To complete the pile construction, hoist the steel cage into the steel casing and pour concrete until it reaches 500 mm above the designed pile top elevation. Simultaneously with the pouring, pull out the steel casing.

[0015] By adopting the above technical solution, before drilling the inclined rock layer, the inclined rock layer is first detected by a probe rod to confirm the surface data of the inclined rock layer, and then the vertical stroke and state of the probe rod when the probe rod rotates at any angle along the inner wall of the steel casing are clarified by drawing the inclined rock surface angular position curve. For example, when the probe rod moves upward, it means that the probe rod is moving toward the upper part of the inclined rock layer; when the probe rod moves downward, it means that the probe rod is moving toward the lower part of the inclined rock layer. It can be seen that when the vertical coordinate of the inclined rock surface angular position curve is at the highest point, corresponding to when the probe rod rotates to this angle position, the probe rod collides with the highest point of the inclined rock surface; when the vertical coordinate of the inclined rock surface angular position curve is at the lowest point, corresponding to when the probe rod rotates to this angle position, the probe rod collides with the lowest point of the inclined rock surface. Therefore, in the case where it is not visually visible, the three-dimensional model of the inclined rock layer can be clearly known through the technical solution of this application, so as to facilitate the construction personnel to handle the inclined rock layer.

[0016] Then, with the help of the obtained three-dimensional model of the inclined rock stratum, arc grooves for the insertion of the hollow cone cylinder are milled layer by layer in the high-level area of the inclined rock stratum through the milling drill bit, so that when the hollow cone cylinder is drilling a hole in the inclined rock stratum, the arc groove can fully guide the rotating hollow cone cylinder, which can effectively avoid the problems of skewness and eccentricity of the drill hole caused by uneven reaction force when the hollow cone cylinder is drilling a hole in the inclined rock surface, thereby ensuring high-quality construction of the pile foundation in the hard rock stratum, effectively reducing the phenomenon of abandoned piles, avoiding waste of construction energy, and ensuring that the construction process is as energy-saving and environmentally friendly as possible.

[0017] Optionally, when collecting data in step S3, the probe rod is placed in close contact with the inner wall of the steel casing and the bottom end of the probe rod is always in contact with the inclined rock layer. The probe rod is rotated along the contour of the inner wall of the steel casing for one circle and the real-time rotation angle of the probe rod along the axis of the inner wall of the steel casing is detected, and the real-time moving stroke of the probe rod in the vertical position is detected; and when the probe rod is rotated, a vibration force in the vertical direction is applied to the probe rod.

[0018] By adopting the above technical solution, when the probe rod is rotated along the inner wall of the steel casing, the position of the probe rod corresponds to the projection point of the inclined rock surface on the inner ring of the steel casing. The vertical movement stroke of the probe rod at this point can be used to characterize the vertical relative height of the inclined rock surface at this point. When the data of each point is sequentially entered on the inclined rock surface angular curve, the inclined surface morphology of the inclined rock layer and the inclined posture at each point can be analyzed more intuitively, which can present a more intuitive three-dimensional model of the inclined rock surface to the construction personnel. In addition, the vertical vibration force is continuously applied to the probe rod when the probe rod is rotated, which helps to ensure that the probe rod avoids the influence of the soil layer during rotation and makes the bottom of the probe rod touch the hard inclined rock surface as much as possible, thereby improving the accuracy of the probe rod detection data.

[0019] Optionally, before cutting the inclined rock layer in step S5, the maximum vertical coordinate value in the inclined rock surface angular position curve is selected as the inclined rock layer vertex, and the minimum vertical coordinate value is selected as the inclined rock layer bottom point; the milling depth of the rock layer is set, and a plurality of parallel cutting lines with a spacing of the depth are drawn in sequence from the inclined rock layer vertex to the inclined rock layer bottom point, the cutting lines are parallel to the horizontal coordinate, and the two intersection points of the cutting lines and the inclined rock surface angular position curve are the cutting starting point and cutting end point.

[0020] By adopting the above technical solution, a cutting line parallel to the horizontal axis is drawn in the angular curve of the inclined rock surface. The obtained cutting starting point and cutting end point are actually two slope points on the inclined rock surface that are almost symmetrical with the apex of the inclined rock surface. When the milling drill bit surrounds the inner wall of the steel casing and mills the inclined rock surface along the height line of the cutting line, an arc groove can be constructed on the inclined rock surface with the shortest rotation stroke, which improves the accuracy of the application during construction and can also improve the construction efficiency to a certain extent.

[0021] Optionally, in step S5 , the arc grooves are milled layer by layer in a “Z”-shaped reciprocating milling manner.

[0022] By adopting the above technical solution, after the milling drill bit cuts a layer of cutting line, it withdraws from the cutting end point on the height line, continues to move down to the cutting starting point on the next layer of cutting line on the same side, and cuts along the cutting line of this layer in a rotating manner. This can greatly reduce the rotation stroke of the milling drill bit along the inner circumference of the steel casing, and there is no need to reposition the milling drill bit after cutting is completed, which significantly improves the efficiency of arc groove construction on inclined rock surfaces.

[0023] Optionally, the probe rod in step S3 and the milling drill bit in step S5 are installed on the same device.

[0024] By adopting the above-mentioned technical solution, arc trough construction can be carried out immediately after the inclined rock surface detection is completed, without the need to frequently lift the main construction equipment, and the detection elements used for the rotation angle of the probe rod and the milling drill bit along the inner circumference of the steel casing can also be shared, without the need for secondary data processing. This greatly simplifies the design and use of construction equipment for the construction process of this application and helps to improve construction efficiency.

[0025] Optionally, the equipment used in step S3 and step S5 is a rotary drilling device, which includes a frame, an extension rod rotatably mounted on the frame, a mounting plate and a guide plate fixedly connected to the bottom end of the extension rod in parallel, the mounting plate being located above the guide plate, the probe rod simultaneously passing through the mounting plate and the guide plate, and an elastic member being provided on the mounting plate for driving the probe rod to remain protruding from the bottom end of the guide plate;

[0026] The milling drill bit is rotatably mounted on the mounting plate, and the frame is provided with a power member and a transmission mechanism for transmitting the rotational power of the power member to the milling drill bit;

[0027] A linear displacement sensor for detecting the lifting stroke of the probe rod is provided on the mounting plate;

[0028] The frame is provided with an angular displacement sensor for detecting the rotation angle of the extension rod;

[0029] The linear displacement sensor and the angular displacement sensor are electrically connected to a controller and a memory or a display screen.

[0030] By adopting the above technical solution, when detecting an inclined rock layer, the extension rod is lowered to the bottom of the pile hole and the probe rod touches the bottom. Then, the data detected by the linear displacement sensor and the angular displacement sensor are calibrated to zero through the controller and set as the origin of the inclined rock surface angular position curve; then the extension rod is driven to rotate slowly and uniformly, and a vertical downward vibration force is continuously applied to the mounting plate during the rotation of the extension rod, so that the probe rod always maintains contact with the inclined rock layer as much as possible during the rotation of the mounting plate. At this time, the elastic member is compressed and deformed; during this process, the linear displacement sensor transmits the detected vertical displacement data of the probe rod to the controller, and the angular displacement sensor transmits the data of the mounting plate rotation angle to the controller. After the mounting plate rotates 360 degrees, the probe rod returns to the origin, and the probe rod completes the collection of detection data. The inclined rock surface angular position curve can be directly generated with the help of the controller, or the inclined rock surface angular position curve can be drawn by reading the data value on the display.

[0031] Then, based on the angular position curve of the inclined rock surface obtained by detection and drawing, an arc groove cutting plan is formulated, and the milling drill bit is driven to rotate through the transmission mechanism to cut the inclined rock layer. During the cutting process of the milling drill bit, the mounting disk is driven to rotate to construct the required arc groove in the inclined rock layer.

[0032] Optionally, the transmission mechanism includes a secondary gear rotatably arranged on the mounting plate and synchronously arranged with the drill rod of the milling drill bit, a long hole arranged along its length direction is opened in the middle of the extension rod, and a transmission shaft with one end coaxially fixed to the output end of the power part and the other end extending to the rotationally connected to the mounting plate is rotatably arranged in the long hole, and a main gear meshing with the secondary gear is coaxially fixed to the transmission shaft.

[0033] By adopting the above technical solution, the power component drives the transmission shaft to rotate, which drives the main gear to rotate. When the main gear rotates, it drives the sub-gear engaged with it to rotate. When the sub-gear rotates, it drives the milling drill bit to rotate, thereby driving the milling drill bit on the ground.

[0034] Optionally, a connecting cover is fixed to one end of the extension rod close to the mounting plate, which covers the outside of the main gear. The connecting cover is fixed to the middle of the mounting plate, and a notch is opened on the peripheral side of the connecting cover for the side of the main gear to extend out to engage with the secondary gear.

[0035] By adopting the above technical solution, the setting of the connecting cover is used to realize the connection between the extension rod and the mounting plate on the one hand, and can also provide a certain degree of shielding for the main gear on the other hand.

[0036] Optionally, a limiting ring located between the mounting plate and the guide plate is fixedly connected to the circumferential side of the probe rod, and the elastic member is located between the limiting ring and the mounting plate; when the limiting ring is pressed against the guide plate, the elastic member is in a compressed state.

[0037] By adopting the above technical solution, when the mounting plate is lowered in the steel casing, the probe rod contacts the inclined rock surface and moves upward on the mounting plate, thereby driving the limit ring to push the elastic part toward the mounting plate, and the elastic part is compressed and deformed; as the probe rod rotates with the mounting plate, the deformation force of the elastic part pushes the probe rod to reset on the mounting plate, and combined with the vertical vibration force applied to the probe rod, the bottom of the probe rod can always contact the inclined rock surface.

[0038] Optionally, a linear driving member is fixedly connected to the peripheral side of the extension rod along its axial direction, and the upper end of the drill rod of the milling drill bit is rotatably arranged on the output end of the linear driving member.

[0039] By adopting the above technical solution, when the probe rod is detecting, the linear drive component drives the milling drill bit to rise close to the guide plate to reduce the rotational resistance of the mounting plate and prevent the milling drill bit from being collided with the inclined rock formation; and when milling the inclined rock formation layer by layer, the linear drive component drives the milling drill bit to gradually descend, thereby achieving precise construction of the inclined rock formation.

[0040] In summary, this application includes at least one of the following beneficial technical effects:

[0041] 1. Before drilling holes in inclined rock formations, the vertical positions of various points in the inclined rock formation are first collected through a probe rod, so that the milling drill bit can mill out relatively symmetrical arc grooves on the sides around the apex of the inclined rock formation. In this way, after the cone hollow cylinder is embedded in the arc groove and in the process of drilling holes in the inclined rock formation, the arc groove can fully guide the rotating cone hollow cylinder, which can effectively avoid the problems of skewness and eccentricity of the drill hole caused by uneven reaction force when the cone hollow cylinder is drilling holes in the inclined rock surface, thereby ensuring high-quality construction of pile foundations in hard rock formations, effectively reducing the phenomenon of abandoned piles, avoiding waste of construction energy, and ensuring that the construction process is as energy-saving and environmentally friendly as possible;

[0042] 2. The detection data obtained by the probe rod in the process of detecting the inclined rock surface is plotted into an inclined rock surface angular curve, which can more intuitively analyze the inclined surface shape of the inclined rock surface and the inclined posture at each point. It can present a more intuitive three-dimensional model of the inclined rock surface to the construction personnel, and enable the milling drill bit to construct an arc groove on the inclined rock surface with the shortest rotation stroke, thereby improving the accuracy of the application during construction and also improving construction efficiency to a certain extent;

[0043] 3. The probe rod and the milling drill bit are both installed on the mounting plate, so that the arc groove construction can be carried out immediately after the inclined rock surface detection is completed, without the need to frequently lift the main construction equipment, and the detection elements used for the rotation angle of the probe rod and the milling drill bit along the inner circumference of the steel casing can also be shared, without the need for secondary data processing, which greatly simplifies the design and use of the construction equipment of the construction process of this application and helps to improve construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a process flow chart of an embodiment of the present application.

[0045] Figure 2 It is a schematic diagram of the overall structure of the rotary drilling device according to an embodiment of the present application.

[0046] Figure 3 It is a coordinate diagram of the inclined rock surface angle curve of the embodiment of the present application.

[0047] Figure 4 It is a structural schematic diagram of the rotary drilling device according to an embodiment of the present application from a front view.

[0048] Figure 5 yes Figure 2 Enlarged schematic diagram of part A.

[0049] Reference numerals: 1, inclined rock layer; 11, arc trough; 12, steel casing;

[0050] 2. Probe rod; 21. Limit ring;

[0051] 3. Milling drill bit; 31. Groove; 32. Linear drive member;

[0052] 4. Inclined rock surface angle curve; 41. Inclined rock layer apex; 42. Inclined rock layer bottom; 43. Cutting line; 44. Cutting start point; 45. Cutting end point;

[0053] 5. Frame; 51. Extension rod; 52. Mounting plate; 53. Guide plate; 54. Elastic member; 55. Power member; 56. Vibration motor; 57. Linear displacement sensor; 58. Angular displacement sensor; 59. Connecting cover; 591. Notch;

[0054] 61, secondary gear; 611, convex strip; 62, transmission shaft; 63, main gear;

[0055] 71. Drive motor; 72. Drive gear; 73. Ring gear. DETAILED DESCRIPTION

[0056] The following is combined with Figure 1-5 This application is described in further detail.

[0057] The present application embodiment discloses a hard rock pile foundation construction process. Figure 1 、 Figure 2 and Figure 3 A hard rock pile foundation construction process comprises the following steps:

[0058] S1. Pile foundation protection: dig a casing pit at the construction site, bury the steel casing 12 in the center and reinforce it.

[0059] S2. Drilling the soil layer, using the drill bit of the rotary drilling rig to drill into the steel casing 12 to the top of the inclined rock layer 1, and stop drilling.

[0060] S3. Detection of inclined rock surfaces: lower a vertically arranged and vertically movable probe rod 2 into the steel casing 12, and collect vertical displacement data of the probe rod 2 as it moves around the inner wall of the steel casing 12; specifically, place the probe rod 2 in close contact with the inner wall of the steel casing 12 and make the bottom end of the probe rod 2 always touch the inclined rock layer 1, rotate the probe rod 2 along the contour of the inner wall of the steel casing 12 for one circle, and detect the real-time rotation angle of the probe rod 2 along the axis of the inner wall of the steel casing 12 and the real-time moving stroke of the probe rod 2 in the vertical position; and when rotating the probe rod 2, always apply a vibration force in the vertical direction to the probe rod 2.

[0061] S4. Data simulation of inclined rock surface, the point where the probe rod 2 is lowered to the inclined rock layer 1 is defined as the origin, the rotation angle of the probe rod 2 along the inner wall of the steel casing 12 is used as the horizontal coordinate, and the movement stroke of the probe rod 2 in the vertical direction is used as the vertical coordinate, and a coordinate diagram for displaying the inclined rock surface angular position curve 4 is drawn; and the maximum vertical coordinate value is selected as the inclined rock layer vertex 41 and the minimum vertical coordinate value is selected as the inclined rock layer bottom point 42 in the inclined rock surface angular position curve 4; the milling depth of the rock layer is set, and then a plurality of parallel cutting lines 43 with a spacing of the depth are drawn in sequence from the inclined rock layer vertex 41 to the inclined rock layer bottom point 42, the cutting line 43 is parallel to the horizontal coordinate, and the two intersection points of the cutting line 43 and the inclined rock surface angular position curve 4 are the cutting start point 44 and the cutting end point 45.

[0062] S5. Cut the inclined rock layer 1, lower the milling drill bit 3 that can move circumferentially around the inner wall of the steel casing 12, and according to the cutting starting point 44 and cutting end point 45 on each cutting line 43 on the inclined rock surface angular curve 4 in step S4, mill out the arc groove 11 along the inner wall of the steel casing 12 at the top of the slope of the inclined rock layer 1 in the form of descending layer by layer.

[0063] S6. Drill a hole by lowering the cone hollow barrel drill and embedding the cone hollow barrel into the arc groove 11. Drill into the bearing layer at the designed elevation through the cone hollow barrel and take a core.

[0064] S7. To complete the pile, hoist the steel cage into the steel casing 12 and pour concrete until it reaches 500mm above the designed pile top elevation. Simultaneously, the steel casing 12 is pulled out during the pouring process.

[0065] Before drilling the inclined rock layer, the probe rod 2 is first rotated along the inner wall of the steel casing 12. The position of the probe rod 2 corresponds to the projection point of the inclined rock surface on the inner circle of the steel casing 12. The vertical movement stroke of the probe rod 2 at this point can be used to characterize the vertical relative height of the inclined rock layer 1 at this point. When the data of each point is sequentially entered on the inclined rock surface angular curve 4, the inclined surface morphology of the inclined rock layer 1 and the inclined posture at each point can be analyzed more intuitively, which can present a more intuitive three-dimensional model of the inclined rock surface to the construction personnel. And when the probe rod 2 is rotated, a vibration force in the vertical direction is continuously applied to the probe rod 2, which helps to ensure that the probe rod 2 avoids the influence of the soil layer when rotating, and makes the bottom of the probe rod 2 contact the hard inclined rock layer 1 as much as possible, thereby improving the accuracy of the detection data of the probe rod 2. Therefore, in the case of non-visual conditions, the three-dimensional model of the inclined rock surface can be clearly known through the technical solution of the present application, so as to facilitate the construction personnel to handle the inclined rock layer 1.

[0066] Then, with the aid of the known three-dimensional model of the inclined rock stratum 1, the milling drill bit 3 is used to mill out arc grooves 11 layer by layer in the high-level area of the inclined rock stratum 1 for the insertion of the roller cone. This allows the roller cone to fully guide the rotating roller cone during the drilling process in the inclined rock stratum 1, effectively avoiding the problem of skewness and eccentricity of the drill hole caused by uneven reaction force when the roller cone is drilling in the inclined rock surface, thereby ensuring high-quality construction of the pile foundation in the hard rock stratum, effectively reducing the phenomenon of waste piles, avoiding waste of construction energy, and ensuring that the construction process is as energy-saving and environmentally friendly as possible. In addition, in the process of machining the arc groove 11 with the aid of the inclined rock surface angular position curve 4, by setting the cutting starting point 44 and cutting end point 45 on the inclined rock surface angular position curve 4, the milling drill bit 3 can construct the arc groove 11 on the inclined rock stratum 1 with the shortest rotation stroke, thereby improving the accuracy of the application during construction and also improving construction efficiency to a certain extent.

[0067] Furthermore, in order to improve the construction efficiency when using this application, on the one hand, referring to Figure 3 In step S5, the arc groove 11 is milled layer by layer in a "Z"-shaped reciprocating milling manner; on the other hand, referring to Figure 2 The probe rod 2 in step S3 and the milling drill bit 3 in step S5 are installed on the same device.

[0068] In this way, after the probe rod 2 completes the detection of the inclined rock layer 1, the arc groove 11 can be constructed immediately without frequently lifting the main construction equipment. In addition, the detection elements for the rotation angle of the probe rod 2 and the milling drill bit 3 along the inner circumference of the steel casing 12 can also be shared, without the need for secondary data processing. This greatly simplifies the design and use of the construction equipment of the construction process of this application and helps to improve construction efficiency. After the milling drill bit 3 cuts a layer of cutting line 43, it withdraws from the cutting end point 45 on the height line, continues to probe the milling drill bit 3 to the cutting starting point 44 on the next layer of cutting line 43 on the same side, and cuts along the cutting line 43 of this layer in a rotating manner. This can greatly reduce the rotation stroke of the milling drill bit 3 along the inner circumference of the steel casing 12, and does not need to reposition the milling drill bit 3 after cutting is completed, which significantly improves the efficiency of constructing the arc groove 11 on the inclined rock layer 1.

[0069] In the specific implementation, the equipment used in step S3 and step S5 is a rotary drilling device, referring to Figure 2 and Figure 4 The rotary drilling device includes a frame 5 and an extension rod 51 rotatably mounted on the frame 5. The bottom end of the extension rod 51 is fixedly connected to a mounting plate 52 and a guide plate 53 arranged in parallel. The mounting plate 52 is located above the guide plate 53. The probe rod 2 passes through the mounting plate 52 and the guide plate 53 at the same time. The mounting plate 52 is provided with an elastic member 54 for driving the probe rod 2 to remain protruding from the bottom end of the guide plate 53. The elastic member 54 is set as a spring; and a limiting ring 21 is fixedly connected to the circumference of the probe rod 2 between the mounting plate 52 and the guide plate 53. The elastic member 54 is located between the limiting ring 21 and the mounting plate 52 and is sleeved on the circumference of the probe rod 2; when the limiting ring 21 is pressed against the guide plate 53, the elastic member 54 is in a compressed state.

[0070] The milling drill bit 3 is rotatably set on the mounting plate 52, and a guide hole for the bevel drill bit to pass through is also provided on the guide plate 53, and the axis of the bevel drill bit and the axis of the probe rod 2 are located on the same concentric circle of the mounting plate 52; the frame 5 is provided with a power member 55 and a transmission mechanism for transmitting the rotational power of the power member 55 to the milling drill bit 3; and in order to achieve the vertical vibration force applied to the probe rod 2 during the detection process, a vibration motor 56 is installed on the mounting plate 52 or the frame 5. To facilitate the setting of the vibration motor 56, the vibration motor 56 is installed on the frame 5, and the frame 5 is a segmented structure with elastic connections between the upper and lower parts.

[0071] And, refer to Figure 4Mounting plate 52 is equipped with a linear displacement sensor 57 for detecting the lifting stroke of the probe rod 2. This linear displacement sensor 57 is a high-precision meter. It is mounted on the upper end surface of mounting plate 52, with its detection portion abutting the side wall of the probe rod 2. Furthermore, frame 5 is equipped with an angular displacement sensor 58 for detecting the rotation angle of the extension rod 51. This angular displacement sensor 58 is mounted on frame 5 and coaxial with the extension rod 51. To process the detection data from the probe rod 2, both linear displacement sensor 57 and angular displacement sensor 58 are electrically connected to a controller and a memory or display screen. The controller is configured as a microcomputer.

[0072] Thus, when detecting the surface of an inclined rock formation 1, the extension rod 51 is lowered to the bottom of the pile hole and the probe rod 2 touches the bottom. The data detected by the linear displacement sensor 57 and the angular displacement sensor 58 are then zeroed by the controller, setting the data as the origin of the inclined rock surface angular position curve 4. The extension rod 51 is then driven to rotate slowly and uniformly. During the rotation of the extension rod 51, the vibration motor 56 is activated and continuously applies a vertical downward vibration force to the mounting plate 52 through the frame 5, so that the probe rod 2 always maintains contact with the inclined rock formation 1 as much as possible during the rotation of the mounting plate 52. At this time, the elastic member 54 is compressed and deformed. During this process, the linear displacement sensor 57 transmits the detected vertical displacement data of the probe rod 2 to the controller, and the angular displacement sensor 58 transmits the rotation angle data of the mounting plate 52 to the controller. After the mounting plate 52 rotates 360 degrees, the probe rod 2 returns to the origin, and the detection data collection of the probe rod 2 is completed. The inclined rock surface angular position curve 4 can be directly generated by the controller, or the inclined rock surface angular position curve 4 can be automatically drawn by reading the data value on the display.

[0073] Similarly, in order to facilitate the cutting of the inclined rock surface by the milling drill bit 3 after the detection of the probe rod 2, refer to Figure 2 and Figure 5 The transmission mechanism includes a sub-gear 61 rotatably mounted on the mounting plate 52 and synchronously mounted with the drill rod of the milling drill bit 3. Specifically, in order to achieve synchronous connection between the sub-gear 61 and the milling drill bit 3, a radially arranged convex strip 611 is fixedly connected to the inner ring of the sub-gear 61. A groove 31 is provided on the circumferential side of the drill rod of the milling drill bit 3 to slideably fit with the convex strip 611. The groove 31 is arranged axially along the milling drill bit 3.

[0074] In addition, a long hole is provided in the middle of the extension rod 51 along its length direction, and a transmission shaft 62 is rotatably provided in the long hole, one end of which is coaxially fixed to the output end of the power member 55 and the other end extends to be rotatably connected to the mounting plate 52. A main gear 63 meshing with the sub-gear 61 is coaxially fixed to the transmission shaft 62; and a connecting cover 59 covering the outside of the main gear 63 is fixed at one end of the extension rod 51 close to the mounting plate 52. The connecting cover 59 is fixed to the middle of the mounting plate 52, and a notch 591 is provided on the circumference of the connecting cover 59 for allowing the side of the main gear 63 to extend to engage with the sub-gear 61.

[0075] At the same time, refer to Figure 2 A linear drive component 32 is fixedly connected to the peripheral side of the extension rod 51 along its axial direction. The upper end of the drill rod of the milling drill bit 3 is rotatably set on the output end of the linear drive component 32. The linear drive component 32 can be a cylinder, a hydraulic cylinder, an electric push rod or a linear motor, etc. In the embodiment of the present application, the linear drive component 32 is set as an electric push rod.

[0076] In this way, when the probe rod 2 is conducting detection, the linear drive component 32 drives the milling drill bit 3 to be lifted up to close to the guide plate 53, so as to reduce the resistance received by the mounting plate 52 from the soil layer when the mounting plate 52 rotates in the steel casing 12, and at the same time, it can also prevent the milling drill bit 3 from being collided with the inclined rock layer 1; and when milling the inclined rock layer 1 layer by layer, the linear drive component 32 drives the milling drill bit 3 to gradually probe downward, and then the power component 55 is started to drive the transmission shaft 62 to rotate, which can drive the milling drill bit 3 to rotate, and can realize precise construction of the inclined rock layer 1 layer by layer.

[0077] And in order to facilitate the rotation of the extension rod 51, refer to Figure 4 The extension rod 51 is coaxially fixed with a ring gear 73 at one end close to the frame 5. A driving gear 72 that meshes with the ring gear 73 is rotatably provided on the frame 5. A driving motor 71 for driving the driving gear 72 to rotate is installed on the frame 5. The driving motor 71 is set as a servo motor.

[0078] The implementation principle of a hard rock pile foundation construction process in an embodiment of the present application is: before drilling the inclined rock layer, first rotate the probe rod 2 along the inner wall of the steel casing 12, and continuously apply a vibration force in the vertical direction to the probe rod 2, detect the real-time rotation angle and real-time vertical movement stroke of the probe rod 2, and draw the detected real-time data into an inclined rock surface angular position curve 4, which can more intuitively analyze the inclined surface shape of the inclined rock layer 1 and the inclined posture at each point, and can present a more intuitive three-dimensional model of the inclined rock surface to the construction personnel; therefore, in the case of non-visual conditions, the three-dimensional model of the inclined rock surface can be clearly known through the technical solution of the present application, so as to facilitate the construction personnel to handle the inclined rock layer 1.

[0079] Then, with the help of the obtained three-dimensional model of the inclined rock surface, the milling drill bit 3 is used to mill out arc grooves 11 for the insertion of the hollow cone cylinder layer by layer in the high-level area of the inclined rock layer 1, so that when the hollow cone cylinder is drilling in the inclined rock layer 1, the arc groove 11 can fully guide the rotating hollow cone cylinder, and can effectively avoid the problems of skewness and eccentricity of the drilling hole caused by uneven reaction force when the hollow cone cylinder is drilling in the inclined rock layer 1, thereby ensuring high-quality construction of the pile foundation in the hard rock layer, effectively reducing the phenomenon of waste piles, avoiding waste of construction energy, and ensuring that the construction process is as energy-saving and environmentally friendly as possible.

[0080] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A hard rock pile foundation construction process, characterized by: The following steps are involved: S1. Pile foundation protection: dig a casing pit at the construction site, bury the steel casing (12) in the center and reinforce it; S2. Drilling the soil layer using a rotary drilling rig drill bit in the steel casing (12) to the top of the inclined rock layer (1), and stopping drilling; S3. Detection of an inclined rock surface, lowering a vertically arranged and vertically movable probe rod (2) in the steel casing (12), and collecting vertical displacement data of the probe rod (2) when it moves around the inner wall of the steel casing (12); S4. Simulate the inclined rock surface data, taking the point where the probe rod (2) is lowered to the inclined rock layer (1) as the origin, taking the rotation angle of the probe rod (2) along the inner wall of the steel casing (12) as the horizontal coordinate, and taking the movement stroke of the probe rod (2) in the vertical direction as the vertical coordinate, draw a coordinate diagram for displaying the inclined rock surface angular position curve (4); S5. Cutting the inclined rock stratum, lowering a milling drill bit (3) that can move circumferentially around the inner wall of the steel casing (12), and milling an arc groove (11) along the inner wall of the steel casing (12) at the top of the slope of the inclined rock stratum (1) in a layer-by-layer manner according to the inclined rock surface angle curve (4) in step S4; S6. Drilling a hole, lowering the cone hollow barrel drill and embedding the cone hollow barrel into the arc groove (11), drilling into the designed elevation bearing layer through the cone hollow barrel, and taking a core; S7 pile, the steel cage hoisted into the steel casing (12), pouring concrete until it reaches 500mm above the designed pile top elevation; and while pouring, pull the steel casing (12); Before cutting the inclined rock layer (1) in step S5, the maximum value of the vertical coordinate is selected from the inclined rock surface angle curve (4) as the inclined rock layer vertex (41) and the minimum value of the vertical coordinate is selected as the inclined rock layer bottom point (42); the depth of the milling rock layer is set, and a plurality of parallel cutting lines (43) with a spacing of the depth are drawn in sequence from the inclined rock layer vertex (41) to the inclined rock layer bottom point (42), the cutting lines (43) being parallel to the horizontal coordinate, and the two intersection points of the cutting lines (43) and the inclined rock surface angle curve (4) being the cutting start point (44) and the cutting end point (45); In the step S5, the arc groove (11) is milled layer by layer in a "Z"-shaped reciprocating milling manner.

2. The hard rock pile foundation construction process according to claim 1, characterized in that: When collecting data in step S3, the probe rod (2) is placed in close contact with the inner wall of the steel casing (12) and the bottom end of the probe rod (2) is always in contact with the inclined rock layer (1). The probe rod (2) is rotated along the inner wall contour of the steel casing (12) for one circle and the real-time rotation angle of the probe rod (2) along the axis of the inner wall of the steel casing (12) and the real-time moving stroke of the probe rod (2) in the vertical position are detected; and when the probe rod (2) is rotated, a vibration force in the vertical direction is applied to the probe rod (2).

3. A hard rock pile foundation construction process according to any one of claims 1-2, characterized in that: The probe rod (2) in step S3 and the milling drill bit (3) in step S5 are installed on the same device.

4. The hard rock pile foundation construction process according to claim 3, characterized in that: The equipment used in step S3 and step S5 is a rotary drilling device, which includes a frame (5), an extension rod (51) rotatably mounted on the frame (5), a mounting plate (52) and a guide plate (53) fixedly connected to the bottom end of the extension rod (51), the mounting plate (52) being located above the guide plate (53), the probe rod (2) simultaneously passing through the mounting plate (52) and the guide plate (53), and an elastic member (54) for driving the probe rod (2) to remain protruding from the bottom end of the guide plate (53); The milling drill bit (3) is rotatably mounted on the mounting plate (52), and a power member (55) and a transmission mechanism for transmitting the rotational power of the power member (55) to the milling drill bit (3) are provided on the frame (5); The mounting plate (52) is provided with a linear displacement sensor (57) for detecting the lifting stroke of the probe rod (2); The frame (5) is provided with an angular displacement sensor (58) for detecting the rotation angle of the extension rod (51); The linear displacement sensor (57) and the angular displacement sensor (58) are electrically connected to a controller and a memory or a display screen.

5. The hard rock pile foundation construction process according to claim 4, characterized in that: The transmission mechanism comprises a secondary gear (61) rotatably mounted on the mounting plate (52) and synchronously mounted with the drill rod of the milling drill bit (3); a long hole is provided in the middle of the extension rod (51) along its length; a transmission shaft (62) is rotatably mounted in the long hole, one end of the transmission shaft being coaxially fixedly connected to the output end of the power member (55) and the other end extending to be rotatably connected to the mounting plate (52); a main gear (63) meshingly connected to the secondary gear (61) is coaxially fixedly mounted on the transmission shaft (62).

6. The hard rock pile foundation construction process according to claim 5, characterized in that: A connecting cover (59) is fixedly connected to one end of the extension rod (51) close to the mounting plate (52) and shielded outside the main gear (63). The connecting cover (59) is fixedly connected to the middle of the mounting plate (52). A notch (591) is provided on the circumference of the connecting cover (59) for allowing the side of the main gear (63) to extend out to engage with the secondary gear (61).

7. The hard rock pile foundation construction process according to claim 4, characterized in that: A limiting ring (21) is fixedly connected to the circumferential side of the probe rod (2) and is located between the mounting plate (52) and the guide plate (53). The elastic member (54) is located between the limiting ring (21) and the mounting plate (52). When the limiting ring (21) is pressed against the guide plate (53), the elastic member (54) is in a compressed state.

8. The hard rock pile foundation construction process according to claim 5, characterized in that: A linear drive member (32) is fixedly connected to the peripheral side of the extension rod (51) and arranged along its axial direction. The upper end of the drill rod of the milling drill bit (3) is rotatably arranged on the output end of the linear drive member (32).

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