A quick-change back-expanding device and a method for expanding

Abstract

The application provides a quick replacement reaming device and a reaming method, a quick replacement reaming device for reaming a guide hole, the quick replacement reaming device comprising a reaming bit, a back-pulling drill rod and a medical-grade rotary joint; the reaming bit comprises a bit body and a dragging piece. In the quick replacement reaming device and the reaming method, when the reaming device performs a reaming operation, the bit is disassembled, then the reaming bit is connected with one end of the drill rod, and the other end of the reaming bit is connected with the back-pulling drill rod through the rotary joint; wherein the bit and the drill rod are connected in a detachable manner, so that the drilling tool can be replaced, and the efficiency of pipe laying construction is improved. In addition, the drilling combination tool is designed, compared with the traditional fixed drilling tool, the drilling equipment does not need to be frequently replaced, and the error of the drilling construction is reduced.

Description

[0001] This application is a divisional application of patent application No. "202110185406.1" with a filing date of "February 10, 2021" and a title of "Trenchless Directional Drilling Pipe Laying Construction Method". TECHNICAL FIELD

[0002] The present application relates to the field of pipe laying construction method, in particular to a quick replacement re-expansion device and reaming method. BACKGROUND

[0003] With the development of urban construction in China, with the continuous improvement of urban appearance and the continuous improvement of traffic and building protection consciousness, at the same time, with the acceleration of old city reconstruction and the continuous expansion of underground pipeline construction, various pipe diameters of pipeline burying engineering are increasing.

[0004] In the underground pipeline laying operation, in order to avoid the defects of hindering traffic, affecting the surrounding environment and low construction efficiency, the non-excavation method is usually used. In the existing trenchless pipe laying construction process, the drill bit is fixed, the processing position is limited, the drill hole and reamer replacement positioning process is complex, the reaming efficiency is low, and the drilling construction error is large, which seriously affects the overall layout scheme of the construction pipeline. Therefore, a quick replacement re-expansion device and reaming method are needed to solve the above technical problems. SUMMARY

[0005] The present application provides a quick replacement re-expansion device and reaming method, which sets up a detachable reaming tool combination to solve the problem of fixed drill bit in the existing pipe laying construction device, limited processing position and low reaming construction efficiency.

[0006] To solve the above technical problems, the technical scheme of the present application is as follows: a quick replacement re-expansion device for reaming a guide hole, comprising:

[0007] A reaming drill bit is detachably connected to one end of a drill rod for expanding the diameter of the guide hole;

[0008] A pull-back drill rod is detachably connected to the other end of the reaming drill bit, the other end of the pull-back drill rod extends out of the guide hole away from the drill machine end, and is used for pulling back the drill rod; and

[0009] A rotary joint is arranged between the reaming drill bit and the pull-back drill rod for adjusting the rotation direction of the pull-back drill rod;

[0010] The reaming drill bit comprises

[0011] A drill bit body is used for rotating reaming; and

[0012] A dragging member is arranged at one end of the drill bit body, and the drill bit body is connected with the rotary joint through the dragging member;

[0013] The rotary joint comprises a first connecting part connected with the dragging member and a second connecting part connected with the back pulling drill rod, and the first connecting part is rotationally connected with the second connecting part;

[0014] The first connecting part comprises two limit members arranged oppositely and forming a clamping opening, and the limit members are connected with the dragging member through bolts,

[0015] The dragging member is arranged in the clamping opening, and the dragging member is connected with the first connecting part through bolts.

[0016] In the present application, the second connecting part is provided with a connecting groove for connecting the first connecting part;

[0017] The first connecting part further comprises a rotating member arranged in the connecting groove, and the first connecting part is rotationally connected with the second connecting part through the rotating member;

[0018] The rotating member extends out of the connecting groove at one end, and the rotating member is connected with the limit member through bolts at one end.

[0019] In the present application, the size of the clamping opening is adjustable, one end of the limit member is provided with an adjusting rod, and the adjusting rod is provided with a limiting block close to one end of the center of the clamping opening,

[0020] The first connecting part further comprises:

[0021] A fixed seat is fixedly connected with one end of the second connecting part, a limiting groove is arranged on the fixed seat, the limiting groove is used for accommodating the adjusting rod, and a stop block is arranged at the opening of the limiting groove; and

[0022] An elastic member is arranged between the limiting block and the stop block, and the elastic member is used for pressing the limiting block.

[0023] In the present application, the two groups of limit members and the fixed seat are adjustably connected.

[0024] In the present application, the fixed seat comprises:

[0025] A first fixed member is fixedly connected with the second connecting part, the limiting groove is arranged on the side of the first fixed member away from the first connecting part, and a first connecting hole is further arranged on the side of the first fixed member away from the first connecting part; and

[0026] A second fixing plate is arranged on the side of the first fixing member away from the first connecting part and between the two limiting members, and a second connecting hole matched with the first connecting hole is arranged on the second fixing plate,

[0027] The first fixing member and the second fixing plate are fixedly connected by fasteners.

[0028] In the application, the limiting member is further provided with a protective plate away from the clamping opening, and the structure of the protective plate is matched with the outer ring structure of the fixing seat.

[0029] The application further provides a reaming method for drilling and laying pipelines in a stratum by using the quick-change reaming device, wherein the stratum comprises a lower digging area, an extension area and an upper digging area arranged in sequence; a drill rig drives a drill rod to drive a guide drill bit to drill from an entry point on the surface of the stratum; the guide drill bit passes through the lower digging area, the extension area and the upper digging area in the stratum in sequence according to a drilling trajectory until the guide drill bit reaches an exit point; the guide drill bit is drilled out or manually dug out; a guide hole is formed in the stratum to connect the entry point and the exit point; and the reaming method comprises the following steps:

[0030] S3: the reaming device performs reaming construction, and the S3 comprises:

[0031] S31: reaming diameter calculation,

[0032] The final reaming diameter is calculated according to the formula: D1=K1xD, wherein D1 is the drilling diameter suitable for laying a finished product pipe; D is the outer diameter of the finished product pipe; and K1 is an empirical coefficient, and K1 is selected from 1.2 to 1.5;

[0033] S32: after the guide hole is formed, the guide drill bit is removed, and a reaming drill bit is connected, the other end of the reaming drill bit is linked with a pullback drill rod, and the reaming drill bit is used for reaming construction through the pullback drill rod;

[0034] The reaming drill bit reams along the guide hole from the position where the guide drill bit is dug out until the guide hole is expanded to a target diameter;

[0035] S33: when the small eye hole of the reaming drill bit can normally spray, the reaming is started;

[0036] S34: the reaming drill bit reams along the guide hole from the position where the guide drill bit is dug out until the guide hole is expanded to a target diameter;

[0037] S4: pipeline laying construction:

[0038] The drill rod is connected with the reaming drill bit, and the other end of the reaming drill bit is connected with a pipeline through a pipe pulling head;

[0039] The reaming drill head is connected with the pipe drawing head through a single-action joint, the single-action joint is used for preventing the pipeline from rotating together with the reaming drill head, so that the pipeline can be smoothly pulled back;

[0040] The laid pipeline is a steel pipe, and the steel pipe is connected with a recyclable grouting pipe at one end close to the reaming drill head.

[0041] In the application, the S34 comprises:

[0042] S341: if the drill is stuck during the drilling process, then:

[0043] S3411: the reaming drill head is stuck due to collision with the underground pipeline, the reaming drill head is withdrawn, the drill rod is pulled back, the drilling machine is shifted, and the guide hole is re-drilled;

[0044] S3412: the drill is stuck due to bricks and stones in the miscellaneous fill, the loosening torque is adjusted, the drill head is rotated, and the reaming is slowly performed; the drill is stuck due to large stones and concrete blocks in the miscellaneous fill, the drill head is withdrawn, the drilling machine is shifted, or the stones are dug out, and the reaming is continued;

[0045] S3413: when the reaming drill head is used for reaming operation, hard clay layer is encountered, the drill is stuck, the reaming speed is slowed down, the amount of mud is increased, and one drill rod is pulled back;

[0046] S3414: the reaming drill head is stuck due to encounter with a tree root, the loosening torque is adjusted, the reaming is slowly performed, the tree root is crushed after passing through the tree root, and the tree root is prevented from being an obstacle during pipeline laying.

[0047] In the application, the S34 further comprises:

[0048] S342: if the guide hole is reduced in diameter during the drilling process, then the drill rod is removed, the water in the hole flows out from the drill rod, the solid-phase mud is selected to protect the wall, the pressure in the hole is balanced, and the hole is maintained;

[0049] or the reaming is performed by adding one drill head, the hole is cleaned, and the pipeline is laid; the PE and PVC pipes with high hardness and high lateral pressure resistance are selected.

[0050] In the application, an entry point is arranged in the lower digging area, an exit point is arranged in the upper digging area, and a straight line direction between the entry point and the exit point is used as a guide track;

[0051] Along the guide track, the length of the lower digging area is L1', the length of the extension area is L2', and the length of the upper digging area is L3',

[0052] The drilling trajectory comprises a first curve part arranged at the lower digging area, a straight line part arranged at the extending area, and a second curve part arranged at the upper digging area, the first curve part and the second curve part are oppositely arranged at two ends of the straight line part, one end of the first curve part is connected with the entry point, and the other end is communicated with one end of the straight line part, one end of the second curve part is connected with the entry point, and the other end is communicated with the other end of the straight line part;

[0053] The length of the first curve part projected on the ground is L1, the length of the straight line part projected on the ground is L2, the length of the second curve part projected on the ground is L3, the depth of the movement trajectory of the guide drill bit in the stratum is H1, the angle between the first curve part and the stratum surface is α1, and the curvature radius of the first curve part is R1,

[0054] L1= , α1= ;

[0055] The angle between the second curve part and the stratum surface is α2, and the curvature radius of the second curve part is R2,

[0056] L3= , α2= ;

[0057] When L1

[0058] Compared with the prior art, the beneficial effects of the present application are as follows: in the quick replacement back-expanding device and hole expanding method, when the back-expanding device performs hole expanding operation, the drill bit is disassembled, then the hole expanding drill bit is connected with one end of the drill rod, and the other end of the hole expanding drill bit is connected with the back-pulling drill rod through a rotary joint; wherein the drill bit and the drill rod are connected in a detachable manner, which facilitates the replacement of the drilling tool and improves the efficiency of pipe laying construction. In addition, by designing the drilling combination tool, compared with the traditional fixed drilling tool, the drilling equipment does not need to be frequently replaced, and the error of the drilling construction is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings needed in the embodiments, and the drawings in the following description are only corresponding drawings of some embodiments of the present application.

[0060] Figure 1 It is a drilling trajectory structure diagram of the preferred embodiment of the quick replacement back-expanding device and hole expanding method of the present application.

[0061] Figure 2Drilling device rear view of a preferred embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0062] Figure 3 Drilling trajectory structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0063] Figure 4 Drilling trajectory structure schematic diagram of a third embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0064] Figure 5 Drilling trajectory structure schematic diagram of a fourth embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0065] Figure 6 Back reaming device structure schematic diagram of a preferred embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0066] Figure 7 Pipe pulling operation structure diagram of a preferred embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0067] Figure 8 Pipe finished product structure schematic diagram of a preferred embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0068] Figure 9 Rotary joint structure schematic diagram of a preferred embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0069] Figure 10 Rotary joint structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0070] Figure 11 Adapter initial position structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0071] Figure 12 Adapter extrusion position structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0072] Figure 13 First fixing member structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0073] Figure 14 Second fixing plate structure schematic diagram of a second embodiment of a quick-change back reaming device and method of reaming according to the invention.

[0074] Reference signs: stratum 11, guide hole 111, exit working pit 112, reinforcing groove 1121, support 113, fixing part 1131, supporting part 1132, limiting block 1132a, drilling trajectory 12, first curve part 121, straight line part 122, second curve part 123, detector 131, ground receiver 132, drilling device 14, drilling machine 141, drill rod 142, drill bit 143, back expansion device 16, back expansion drill bit 161, drill bit body 1611, pulling member 1612, back pulling drill rod 162, rotary joint 163, first connecting part 1631, limiting member 16311, rotating member 16312, second connecting part 1632, connecting groove 16321, mud layer 17, second drilling device 18, pipeline 19.

[0075] First embodiment drilling trajectory Reference signs: entry point A1, first curve part and straight line part trajectory change point B1, straight line part and second curve part trajectory change point C1, exit point D1, length of the first curve part projected on the ground L1, length of the straight line part projected on the ground L2, length of the second curve part projected on the ground L3, radius of curvature of the first curve part R1, radius of curvature of the second curve part R2, depth of the trajectory of the movement of the drill bit in the stratum H1, drill bit entry angle a1, drill bit exit angle a2.

[0076] Second embodiment drilling trajectory Reference signs: stratum 21, second working pit 212, entry point A2, B2 is the first curve part and straight line part trajectory change point, C2 is the straight line part and second curve part trajectory change point, depth of the trajectory of the movement of the drill bit in the stratum H2.

[0077] Third embodiment drilling trajectory Reference signs: stratum 31, entry point A3, B3 is the first curve part and straight line part trajectory change point, C3 is the straight line part and second curve part trajectory change point, depth of the trajectory of the movement of the drill bit in the stratum H3, first working pit 313, second working pit 312.

[0078] Fourth embodiment drilling trajectory Reference signs: stratum 41, support structure 411, depth of the trajectory of the movement of the guide drill bit in the stratum 41 H, length of the first curve part projected on the ground L4.

[0079] Second embodiment rotary drill bit Reference signs: rotary joint 5, first connecting part 51, limiting member 511, adjusting rod 512, limiting block 513, protective plate 514, fixing seat 515, first fixing member 5151, limiting groove 5151a, stop block 5151b, first fixing hole 5151c, second fixing plate 5152, second fixing hole 5152a, elastic member 5153, avoiding notch 5154, second connecting part 52. DETAILED DESCRIPTION

[0080] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0081] In the drawings, similar elements are denoted by the same reference numerals.

[0082] The terms "first", "second", and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance, and are not limited as the order of precedence.

[0083] Please refer to Figure 1 and Figure 2 , wherein Figure 1 is a schematic diagram of a drilling trajectory structure of a preferred embodiment of a quick replacement back-expanding device and a hole expanding method of the present application, Figure 2 is a rear view of a drilling device of a preferred embodiment of a quick replacement back-expanding device and a hole expanding method of the present application.

[0084] The following is a preferred embodiment of a quick replacement back-expanding device and a hole expanding method provided by the present application, which can solve the above technical problems.

[0085] The present application provides a quick replacement back-expanding device and a hole expanding method, which is applied in trenchless directional drilling pipe laying construction operation. A quick replacement back-expanding device is briefly referred to as back-expanding device. The preferred embodiment of the present application is:

[0086] The quick replacement back-expanding device and the hole expanding method are applied in trenchless directional drilling pipe laying construction operation. The trenchless directional drilling pipe laying construction is used for drilling and laying pipes in strata. The strata include a lower excavation area, an extension area and an upper excavation area arranged in sequence. The trenchless directional drilling pipe laying construction steps include:

[0087] S1: Designing a guide trajectory and a drilling trajectory according to geological survey data.

[0088] The specific steps of S1 are:

[0089] S111: Collection of construction site pre-stage data

[0090] Trenchless directional drilling construction is a kind of construction method with certain risk, so it is particularly important to do well the preparatory work before drilling construction. The stratum condition information of trenchless construction site should be understood and collected, and if necessary, professional geotechnical engineering investigation should be carried out to obtain detailed information of underground soil layer. Because trenchless horizontal directional drilling pipe laying construction is an underground soil drilling engineering, various strata may be encountered, and different strata have great influence on trenchless directional drilling pipe laying construction. Therefore, sufficient understanding of stratum distribution is an important factor for the efficiency of trenchless horizontal directional drilling construction, and sometimes it may even affect the success or failure of the project.

[0091] S112: Investigation and detection of underground pipelines at construction site

[0092] For trenchless horizontal directional drilling pipe laying construction, it is particularly important to fully understand the distribution and burial depth of underground pipelines in the construction area. Various means and methods should be used to obtain information about the original underground pipelines before construction. The underground pipelines should be investigated by checking the pipeline-related drawings and layout at the construction site in the construction planning department, and by finding the pipelines indicated on the drawings in the field. The distribution, trend, position and pipe diameter of the underground pipelines can be investigated and detected by using underground pipeline detection instruments and ground penetrating radar method, and if necessary, manual exploration can be used, which is more intuitive and accurate. The relevant pipeline ownership units should be contacted to confirm and brief the site.

[0093] S12: Design of drilling trajectory

[0094] The design of drilling trajectory is the basis for trenchless directional drilling construction and the standard for quality inspection. The design of trajectory not only considers avoiding underground pipelines in the crossing area, but also considers hydrogeology, ground environment, pipe diameter and material of laid pipeline, crossing length and depth, bending radius of drilling machine and pipe material. The actual construction trajectory of the pipeline should meet the design requirements, and the entry point, exit point, straight section and curve section length should be considered, and the elevation of each point in the horizontal crossing section should be strictly controlled.

[0095] In this embodiment, the design of drilling trajectory sets an entry point in the down-digging area and an exit point in the up-digging area, and the straight line direction between the entry point and the exit point is the guide trajectory; along the guide trajectory, the length of the down-digging area is L1', the length of the extension area is L2', and the length of the up-digging area is L3'.

[0096] The drilling trajectory 12 in the embodiment comprises a first curve portion 121 arranged in the lower digging area, a straight line portion 122 arranged in the extending area, and a second curve portion 123 arranged in the upper digging area, the first curve portion 121 is arranged at the two ends of the straight line portion 122 opposite to the second curve portion 123, one end of the first curve portion 121 is connected with the entry point, and the other end is communicated with one end of the straight line portion 122, one end of the second curve portion 123 is connected with the entry point, and the other end is communicated with the other end of the straight line portion 122.

[0097] The calculation of the curvature radius of the pipeline is determined by the bending characteristics of the pipeline to be laid, and the greater the diameter of the pipeline, the greater the curvature radius.

[0098] When the pipeline to be laid is a steel pipe, the minimum bending radius of the steel pipe is Rmin, the outer diameter of the steel pipe is D (mm), the safety factor is S, and S is between 1 and 2, and the yield limit of the steel pipe is K2 (N / mm2); wherein Rmin= 206·D·S / K2 (m).

[0099] When the pipeline to be laid is a PE pipe, the minimum curvature radius of the PE pipe is p, the elastic modulus is E (Mpa), the outer diameter of the pipe is DH (cm), and the bending stress is p (Mpa); wherein p= .

[0100] The depth of the trajectory of the pilot bit 143 in the stratum 11 is H1, the angle between the first curve portion 121 and the surface of the stratum 11 is a1, and the curvature radius of the first curve portion 121 is R1; wherein L1= , a1= .

[0101] The angle between the second curve portion 123 and the surface of the stratum 11 is a2, and the curvature radius of the second curve portion 123 is R2; wherein L3= , a2= .

[0102] When L1 Figure 1 , and L3 .

[0103] When L3 Figure 2 ; wherein A2 is the entry point, B2 is the trajectory change point of the first curve portion and the straight line portion, C2 is the trajectory change point of the straight line portion and the second curve portion, and the depth of the trajectory of the drill bit in the stratum is H2. Similarly, when L1

[0104] When laying the steel pipe with large pipe diameter (D>200mm), the distance between the guide hole 111 and the ground is increased due to the too large bending radius R2 and the corresponding increase of L3, and the material is wasted, therefore, under the condition that the site condition is satisfied, the excavation of the working pit for laying the pipe is preferred to replace the second deflecting section.

[0105] When laying the steel pipe with large pipe diameter (D>400mm), under the condition that the site condition is satisfied, the working pit should be excavated at the entrance point A3 and the exit point C3 of the stratum 31 to carry out the construction. As shown in the figure, Figure 3 , wherein A3 is the entrance point, B3 is the change point of the first curve and the straight line, C3 is the change point of the straight line and the second curve, the depth of the movement track of the drill bit in the stratum is H3, the entrance point A3 is arranged in the first working pit 313, the exit point is arranged in the second working pit 312, and C3 is also arranged in the second working pit 312.

[0106] When L1>L1', and the length difference between L1 and L1' is within the first set range; in the embodiment, the first set range is preferably between 0m and 0.5 times the length of L1. As shown in the figure, Figure 4 , the support structure 411 is arranged at the entrance point A4 of the stratum, and the depth of the movement track of the guide drill bit in the stratum 41 is H, with the plane where the top surface of the support structure 411 is located as the reference, the projection of the first curve on the surface of the stratum 41 is L 4， , and L4

[0107] S2: construction of the guide hole 111;

[0108] S21: excavation and support of the working pit and installation and positioning of the drill 141; the specific steps are as follows:

[0109] S211: excavation and support of the working pit

[0110] The size of the entrance and exit working pits should be determined according to the site condition, the type of the pipeline, the pipe diameter, the material, the buried depth, the geological condition and the design parameters of the guide track, and the shape, size and depth of the working pit are generally rectangular. When the depth is deep, the stability of the pit wall during excavation must be considered, and the corresponding support method must be adopted, and the overall rigidity, stability and support strength must be checked. When considering the function of the pit, if the exit pit is used for pipe connection, the operation space for welding should be considered, and if the diameter of the pipeline to be laid is large, the exit pit must be extended into a long groove suitable for the straight pulling back of the pipeline.

[0111] S212: installation and positioning of the drill; the specific steps are as follows:

[0112] S2121: selection of the drill ​

[0113] Once the construction conditions are known and the borehole design trajectory is confirmed, the selection of a horizontal directional drilling rig mainly considers the following factors:

[0114] The drilling design considers factors such as the final borehole diameter, the radius of curvature of the borehole, and the length of the pipeline to be laid. Based on these factors, the drilling rig is selected and determined using rotational torque and pullback force. Considering the complexity of the drilling, the selected drilling rig's capacity should be at least 30% greater than the calculated requirement.

[0115] After evaluating factors such as site topography, transportation conditions, pipeline burial depth, and working location, a choice is made between surface-starting drilling rigs and pit-starting drilling rigs.

[0116] Surface-starting drilling rigs are typically tracked or wheeled, equipped with a walking mechanism, allowing them to move autonomously to the work site. Several anchoring methods are available for anchoring these rigs to the ground; sophisticated anchoring systems can be hydraulically driven. Some surface-starting drilling rigs are fully integrated, carrying a drilling fluid mixing tank and pump, as well as power auxiliary devices, valves, and control systems. Some also feature an automatic drill rod loading and unloading system, where fixed-length drill rods are mounted on a "transfer plate" and automatically added to or removed from the drill rod string during drilling or reaming. In other cases, the mixing tank and pump are separate components.

[0117] Pit-launching drilling rigs are generally small in size. During construction, working pits need to be excavated at both ends of the borehole. However, they can operate in places with limited space. Some drilling rigs designed to be more compact only need to have a working pit that is only slightly larger than the pit required for connecting pipes. The pit-launching drilling rig is fixed in the working pit, using the front and rear walls of the pit to bear the feed and pullback forces.

[0118] S2122: Drilling rig placement 141

[0119] Before drilling rig 141 arrives on site, working pits must be excavated at the entry and exit points of the borehole. After the working pits are excavated, drilling rig 141 can be placed. The placement of drilling rig 141 mainly considers the entry angle of the designed drill rod 142. The angle and direction of drilling rig 141 should be adjusted according to the entry angle of the designed drill rod 142. The equipment should be installed at the starting position of the extension of the production pipeline centerline, and the frame orientation should be adjusted to conform to the designed borehole axis. After drilling rig 141 is placed, it needs to be anchored. If the soil layer is hard and dry, straight anchor rods can be used. If the soil layer is loose, concrete foundations or caisson spiral anchor rods can be used for anchoring. The anchoring capacity of drilling rig 141 reflects its ability to exert its own power during feeding and pulling back operations.

[0120] After the drilling rig 141 is in place, a suitable drill bit 143 and drill string combination is selected according to the different soil layer conditions of the construction site, and the drill string combination is checked and installed. The greater the torque and the higher the speed of the drilling rig 141, the higher the reaming efficiency. Under the rated torque and speed conditions of the drilling rig 141, the reaming efficiency is directly related to the reamed soil layer, the reaming bit 161, the quality and quantity of the reaming mud. To improve the reaming efficiency, the soil layer structure and soil composition must be understood, the high-efficiency drill bit 143 suitable for cutting the soil layer must be selected, and the mud suitable for the soil layer and the reasonable mud quantity must be prepared to carry out reaming, and the reaming efficiency is high.

[0121] S22: Mud preparation and drilling a pilot hole 111.

[0122] S221: Preparing mud

[0123] Mud refers to a mixture of water and bentonite or polymer, and sometimes some mud treatment agents need to be added. The basic substances for non-excavation drilling mud are water and clay, and the influence of clay on the performance of mud is a decisive factor. The properties and performance of mud mainly depend on the mineral type of clay particles, their properties in water, the size and distribution of dispersed particles, the total content of distributed clay, and the effects of these particles and treatment agents. The clay used for non-excavation is mainly bentonite, which has loose intercellular connections, a large number of exchangeable cations, and easy entry of water molecules into the intercellular space, so it is easy to swell and hydrate, has good dispersibility, and has a high mud-making rate. Since general bentonite is calcium bentonite, in order to improve the mud-making performance of calcium bentonite, it must be alkali-treated. When calcium bentonite is used for mud preparation, a proper amount of soda ash is added to change the properties of the soil and make it into sodium bentonite. Generally, the proportion of added soda ash (sodium carbonate) is about 5%-6% of the weight of the clay. The water used for mud preparation is generally taken from the local water source, but it requires clean, impurity-free, and pollution-free water. In order to ensure the stability of the mud during drilling and improve the performance of the mud to meet the drilling requirements under various conditions, the mud must be chemically treated. Adding mud treatment agents is a common method for treating mud. Treatment agents are divided into inorganic treatment agents and organic treatment agents, and different mud treatment agents can be selected for treatment according to different soil layers.

[0124] Mud quantity calculation: the mud volume V per meter of the borehole = 0.785 × (D²-d²) × coefficient; the total amount of chemical mud additives T = t × V; wherein V is the required mud volume (cubic meters); D is the diameter of the large reamer (meters); d is the diameter of the small reamer or the pilot hole 111 (meters), T is the total amount of chemical mud additives (kilograms); t is the reference amount of chemical mud additives added per cubic meter of water (kilograms); the coefficient value should be selected according to the soil quality, pipe diameter, length, reaming times, etc. The coefficient value in this embodiment should be between 1.5 and 3.

[0125] Further, the drilling operation in the embodiment is accumulated by the amount of mud used when the different diameters of the drill bit 143 are reamed; when the same diameter reamer is used for reaming multiple times, d = 0 is taken.

[0126] The mud preparation procedure in the embodiment is as follows: first, a certain proportion (0.1-0.2%) of soda ash is added to the extracted water; then a certain proportion of bentonite is added, and the bentonite is fully dissolved in water and completely dispersed by mechanical stirring, which generally needs about 20 minutes; finally, a certain proportion of additives is added, and stirring is performed for 3-5 minutes to obtain the mud.

[0127] S222: Selecting a guiding device

[0128] For trenchless directional drilling projects, the positioning and guiding instrument is a very critical device. For different construction conditions, the correct selection and use of suitable guiding instruments are the main factors that determine the success or failure of the project. The selection of the steering device is mainly based on the design trajectory of the drilling, the topography of the site, the interference of electromagnetic signals, the length of continuous working time, and other factors. According to the actual situation of the site and considering the technical requirements and construction costs of the construction, different performance and precision steering devices can be selected for construction.

[0129] There are several types of guiding systems, mainly including handheld tracking systems and cable-guided systems. The positioning and guiding performance of both systems can meet the needs of conventional horizontal directional drilling crossing projects. At present, the most widely used positioning system is the handheld tracking (walk-over) system, which is based on a probe or a detector installed in the cavity behind the drill bit. The radio signals emitted by the probe are received by the ground receiver held by the steering personnel. After processing by the receiver, the received signals show various parameters of the received signals.

[0130] S223: Drilling a guiding hole.

[0131] Drilling a guiding hole is the most important stage of horizontal directional drilling construction, which determines the final position of the pipeline. The construction of the guiding hole should meet the following requirements:

[0132] S2231: After the drilling machine 141 is started, a trial run should be performed to determine that all parts of the equipment are operating normally before drilling. In the guiding device, the probe 131 is fixed on the guiding drill bit 143. The probe 131 is used to emit radio signals, and the ground receiver 132 is set on the surface of the stratum 11 to receive the radio signals emitted by the probe 131, showing various parameters of the received radio signals. This facilitates the operator to timely detect the deviation of the drilling trajectory and timely correct the deviation.

[0133] S2232: When the first drill pipe 142 is drilled into the ground, it should be gently pressed and slowly rotated to stabilize the position in the ground. After the design angle of the ground is met, drilling can be carried out. With the aid of the jet drilling of the drilling fluid, the borehole continuously extends forward. In hard rock formations, a mud motor is required for drilling. The end of the drill pipe 142 has a bend joint to control the direction of the trajectory.

[0134] During drilling, the receiver receives and displays various parameters of the build-up surface angle, and synchronously displays on the remote display of the drilling machine 141. The operator should master the situation of the drill bit 143 and the borehole trajectory in the hole according to the display. When it is found that the borehole trajectory deviates from the original design trajectory, the operator adjusts the direction of the build-up surface of the drill bit 143 to correct the deviation, until the actual position of the drill bit 143 is the same as the design trajectory of the borehole. In this way, a guide hole 111 with the same design trajectory is drilled.

[0135] S2233: When the guide hole 111 is drilled, the ground receiver 132 moves along the guide trajectory from the entry point to the exit point along the surface of the stratum 11; at the same time, the drill pipe 142 drives the guide drill bit 143 to drill from the entry point on the surface of the stratum 11. The guide drill bit 143 successively passes through the under excavation area, the extension area and the over excavation area inside the stratum 11 along the borehole trajectory, until the drill bit 143 reaches the exit point position, and the drill bit 143 is drilled out or manually excavated out.

[0136] Among them, the measurement frequency of the build-up section is generally 0.5-1.0m per time, and the measurement frequency of the straight section is generally once per drill pipe 142. When the original underground pipeline position, the key entry and exit point, the hole with slope requirement for drilling, or the adjustment of the borehole trajectory, the measurement frequency should be increased. The measurement data is compared with the design trajectory to correct the deviation at any time to confirm the direction of the next section to be drilled.

[0137] When drilling in a curved section, the pushing force should be adjusted according to the conditions of the stratum 11 to avoid excessive bending of the drill pipe 142.

[0138] When the build-up section is jacked, the jacking length should be less than 0.5-1.0m at a time, and the extension length top angle variable should be observed. The top angle variable should meet the requirements of the bending strength limit of the drill pipe 142. The extension length top angle should be changed uniformly by segment drilling.

[0139] The trajectory deviation error between the adjacent two measurement points of the guide hole 111 should not be greater than the final hole diameter. The deviation error should be corrected in time.

[0140] S2234: When the drill bit 143 is exposed at the exit pit

[0141] When the surface, the actual point of the earth should be measured whether within the allowable error range. If a part of the borehole exceeds the error range, the drill pipe 142 can be pulled back, and the deflection part of the borehole is drilled again. When the point of the earth meets the requirements, the drill bit 143 and the related drilling tools are removed, and the reaming and pulling back are started.

[0142] S2235: drilling fluid

[0143] The drilling fluid is generally drilling mud, which plays an important role in the non-excavation directional drilling construction. The drilling fluid is used for carrying drill cuttings, stabilizing the borehole wall, reducing the rotary torque and pipe pulling resistance, cooling the drill bit, launching the probe, and jetting drilling, etc. It is regarded as the "blood" of the directional drilling. The drilling fluid in the annular space between the pipe and the borehole wall also has the functions of suspension and lubrication, which is beneficial to the subsequent pipe pulling back. The drilling mud is pumped into the drill pipe 142 by the mud pump, sprayed out from the nozzle of the drill bit 143, and then returned to the ground through the annular gap between the drill pipe 142 and the borehole wall. The mud returned from the borehole needs to be treated by a mud settling tank or a mud purification device before being sent back to the mud tank or mixed with new mud for reuse. The drilling fluid is a mixture of clear water, bentonite, a small amount of polymer, and a processing agent.

[0144] S3: The reaming device 16 performs reaming construction, and the reaming device 16 is as shown in FIG. 2. The reaming steps are as follows: Figure 6

[0145] S31: Reaming diameter calculation: in the construction method of the present application, according to the diameters of the guide hole 111 and the suitable product pipe laying hole and the stratum 11, the reaming can be performed once or multiple times. When the same diameter is laid, the guide hole 111 is completed, and the pipe can be directly laid back. However, most of the guide holes 111 need to be enlarged by a reamer to be able to install the product pipeline, and the main purpose of reaming is to enlarge the borehole diameter. The final reaming diameter formula is D1=K1×D calculation; wherein D1 is the diameter of the borehole suitable for laying the product pipe; D is the outer diameter of the product pipe; K1 is an empirical coefficient, generally K1 is taken as 1.2-1.5, when the stratum 11 is homogeneous and complete, K1 takes a small value, and when the stratum 11 is complex, K1 takes a large value.

[0146] S32: After the guide hole 111 is formed, the guide drill bit 143 installed at the front end of the drill pipe 142 during the construction of the guide hole 111 is first removed at the exit pit; secondly, the front end of the drill pipe 142 is connected to one end of the reaming drill bit 161 through the rotary joint 163, and the other end of the reaming drill bit 161 is linked with the pulling back drill pipe 162, and the reaming drilling construction is performed through the pulling back drill pipe 162.

[0147] ​S33: Hole reaming can only begin when the small hole of the reamer bit 161 (reamer) can be sprayed with grout normally. Dry reaming is strictly prohibited.

[0148] S34: Starting from the exit position of the guide drill bit 143, the reaming drill bit 161 reams the hole along the guide hole 111 until the guide hole 111 is reamed to the target hole diameter. After the reaming drill bit 161 reaches the working pit on one side of the drilling rig 141, the reamer and rotary joint are removed, and the drill rod 142 on the drilling rig 141 is connected to the pullback drill rod 162. Then, after the connecting drill rod 142 in the exit pit, another larger reamer and rotary joint are connected, and then the second pullback drill rod 142 is connected to perform the second reaming drilling. The reaming is repeated until the requirements are met.

[0149] When enlarging a hole, the operator should enlarge the hole step by step according to the matching enlarging drill bit, starting with the smallest size. The diameter of the enlarging drill bit is generally 100, 300, 500, 700, 900, 1100, 1300, and 1500 mm. Medium and large drilling rigs can enlarge the hole by skipping one size of drill bit diameter in soft soil.

[0150] If abnormal torque or tension occurs during hole reaming, the hole should be cleaned (by drilling once or several times to keep the hole clear). After the hole is cleaned, the hole reaming operation can continue.

[0151] S4: Pipe laying construction, pipe pulling device pulls back the pipe material:

[0152] Once the borehole has been enlarged to the required diameter, the precast pipe to be laid can be pulled into the hole filled with mud. It is best to pre-connect all the pipes to facilitate pulling them in one go. The strength and ring stiffness of the pipe material must meet the load requirements of the design and construction phases. If the stratum 11 is complex, such as with borehole diameter reduction or borehole wall collapse, it may cause difficulties in pulling the pipe in sections.

[0153] S41: Before pulling the pipe, connect two Φ23~Φ27 steel pipes of the same length as the PE pipe at the front end of the pipeline. In this embodiment, Φ25 steel pipe is preferred.

[0154] S42: As Figure 7 As shown, during pipe pullback, drill rod 142 is connected to reaming drill bit 161, and the other end of reaming drill bit 161 is connected to pipeline via pipe pull head; wherein, reaming drill bit 161 and pipe pull head are connected by a single-acting joint, the single-acting joint is used to prevent pipeline from rotating together with reaming drill bit 161, thereby ensuring that pipeline can be pulled back smoothly; at this time, steel pipe and pipeline are pulled into the soil together and reach the design end point of pipe pull together.

[0155] The formula for calculating the back-dragging force is: the gravity of the pipe is G=pgpipevg; the buoyancy of the pipe in the hole is Fbuoy=pmudvg; the side friction of the pipe is Ffriction=(Fbuoy-G)xf1; the adhesion of the pipe during back-dragging is Fstick=31.4xDxLxf2; the resistance of the pipe during back-dragging and hole expansion is Fexpand=62.8xD; the maximum pulling force of the pipe during pipe pulling is Fpipe=Fstick+Fexpand; and the maximum pulling force of the drilling machine 141 during pipe pulling is Ftotal=Fstick+Fexpand+Ffriction.

[0156] wherein pgpipe is the density of the pipe material (kg / m3); pmud is the density of the mud (kg / m3); v is the speed of the back-dragging pipe material (m / s); vdisp is the volume of the pipe material dispelled by the mud (m3); f1 is the friction coefficient of the pipe material with the hole wall in the mud; f2 is the adhesion coefficient of the mud adhered to the pipe surface; D is the outer diameter of the pipe material (m); L is the length of the pipe material (m); and g is 9.8 N / kg.

[0157] S43: After the pipeline back-pulling is completed, the steel pipe is disconnected from the pipeline at one end. The steel pipe is connected to a recyclable grouting pipe at the end close to the hole-expanding drill 161.

[0158] S5: Grouting and reinforcement construction:

[0159] The gap between the pipeline and the guide hole 111 is grouted through the recyclable grouting pipe. After grouting is completed, the recyclable grouting pipe is pulled out. The guide hole 111 and the pipeline are filled with a mud layer 17, which is used to fill the gap around the pipeline and reinforce the stratum 11. Step S5 includes:

[0160] S51: A pipe-pulling machine is connected to both ends of the steel pipe, and a 5-7 m long grouting flower pipe of the same diameter is added to each end of the steel pipe.

[0161] S52: The pipe-pulling machine pulls the steel pipe by 5-7 m, disconnects the steel pipe from the pipe-pulling machine, connects one end of the steel pipe to the high-pressure grouting pump, and then performs single grouting operation.

[0162] S52: After the single grouting operation is completed, the connection between the steel pipe and the high-pressure grouting pump is disconnected, and the connection between the steel pipe and the pipe-pulling machine is replaced to pull the steel pipe by 5-7 m. The steel pipe is disconnected from the pipe-pulling machine, and then one end of the steel pipe is connected to the high-pressure grouting pump. Then, single grouting operation is performed. Step S52 is repeated until the steel pipe is completely pulled out, and the grouting and reinforcement construction is completed.

[0163] The preferred scheme of the grouting reinforcement construction in the embodiment is as follows: one 6m long and same diameter grouting flower pipe is added in front of each of the two steel pipes; every time the steel pipe is pulled in by 6m, the connection between the steel pipe and the pipe pulling machine is cancelled, the connection between the steel pipe and the high-pressure grouting pump is replaced, 1:1 cement and fly ash slurry (0.4Mpa) is injected to replace the thixotropic mud and supplement the voids around the pipeline; then the connection between the steel pipe and the high-pressure grouting pump is cancelled, the connection between the steel pipe and the pipe pulling machine is replaced to pull the steel pipe; the steel pipe is pulled in by 6m again, the connection between the steel pipe and the pipe pulling machine is cancelled, the connection between the steel pipe and the high-pressure grouting pump is replaced to inject the mud; the above steps are repeated until the steel pipe is pulled out completely and the grouting operation is completed.

[0164] The application fills the gap between the pipeline 19 and the guide hole 111 with the recyclable grouting pipe, pulls out the recyclable grouting pipe after grouting is completed, and needs to be grouted after the pipe is pulled out to avoid ground subsidence, improve the bearing capacity of the foundation, effectively prevent pipe heaving and cut off the water source. Figure 8 The schematic view shows that the outer wall of the pipeline 19 and the inner wall of the guide hole 111 are both filled with the mud layer 17, the mud layer 17 is used for filling the gap around the pipeline 19, and the stability of the whole pipe laying structure is ensured.

[0165] S6: backfill the working pit to complete the pipeline laying.

[0166] After the pulling back is completed, the pipe head should also be pulled out by a length, generally about 3% of the total length of the pipe material, and the ends of the finished pipe should be sealed to avoid foreign matters from entering the pipe. According to different uses of the pulled back pipe material, the pipe material related test should also be carried out, after the test is qualified, the site mud, slag and waste should be cleaned in time, and the working pit should be backfilled and compacted according to the requirements.

[0167] The reaming step S34 in the embodiment is described in detail as follows:

[0168] S341: drill pipe sticking during drilling. Drill pipe sticking is a common technical difficulty in reaming. After the cause is analyzed and determined, the drill pipe sticking is treated.

[0169] S3411: the reamer bit 161 collides with the underground pipeline and sticks, the reamer bit 161 is withdrawn, the drill pipe 142 is pulled back, the drilling machine 141 is shifted, and the guide hole 111 is re-drilled.

[0170] S3412: brick and stone in the miscellaneous fill stick: loosen the torque, rotate the drill bit 143, and slowly ream; large stones and concrete blocks in the miscellaneous fill stick: the drill bit 143 is withdrawn, the drilling machine 141 is shifted and re-drilled, or the stone is dug out and the reaming is continued. Do not force, otherwise the drill pipe 142 will be twisted and broken, and the drill will be lost in the hole.

[0171] S3413: When the large-diameter reamer bit 161 is reaming, it encounters a hard clay layer, causing frequent sticking, slowing down the reaming speed, increasing the amount of mud, and sometimes pulling back a drill pipe 142, which takes 40 minutes.

[0172] S3414: The reamer bit 161 encounters a tree root and gets stuck, the loosening torque is slow, and after passing through the tree root, it is re-reamed again to crush the tree root to prevent obstacles during pipe laying.

[0173] S342: During the drilling process, the pilot hole 111 is reduced in diameter. Soft soil layer reaming, hole content is prone to shrinkage phenomenon.

[0174] After the drill pipe 142 is removed, the water in the hole flows out from the drill pipe 142, indicating that the hole is severely reduced in diameter. When the diameter is severely reduced, the laid pipe will be squeezed and deformed, or even stuck. When encountering severe shrinkage, solid phase mud is used to protect the wall, so that the pressure in the hole is balanced and the hole is maintained. Or increase the reaming of the next level bit 143, then clean the hole and lay the pipe. If the shrinkage is slight, the hole is usually cleaned once and the pipe is laid.

[0175] S343: Hole collapse.

[0176] Among them, the sandy clay layer, sand layer, loose backfill layer is easy to collapse during reaming. Collapse of buried drill, stuck, stuck pipe, causing road surface cracks and subsidence. The use of solid phase mud, heavy colloidal solid phase mud wall protection can effectively prevent the collapse of the hole. If it is a stone accumulation place, only after the stones are removed can the reaming continue.

[0177] S344: Hole expansion.

[0178] Clay layer, Xigeda bottom layer expands when it encounters water: when drilling and laying pipes in this type of soil layer 11, the soil layer expands after the pilot hole 111 is drilled, the amount of mud in the hole increases, and the hole diameter decreases. The laid pipe is prone to stretching. At this time, high-quality solid phase protection is selected, the mud loses less water, and the contact between the hole wall and water is reduced. Expanding the next level reaming, cleaning the hole twice can effectively prevent the expansion of the soil layer 11 and squeeze the pipe.

[0179] S345: Mud loss.

[0180] In loose backfill soil layer, the groundwater level is low, the sandy silt layer, silt layer, sand layer, and riverbed bottom soft soil layer, and the sand layer is reamed. The mud does not return from the hole, but leaks from the hole, increases the concentration and viscosity of the mud, and forms a mud skin on the hole wall to prevent mud loss. When crossing a river, mud loss and inability to block leakage are natural.

[0181] The following describes the construction method of laying pipes in different soil layers in detail:

[0182] When laying pipes in the quicksand layer:

[0183] The quicksand layer expands the hole, and after the hole is expanded, a complete hole cannot be formed, and the quicksand has adsorption characteristics, causing resistance to pipe laying.

[0184] Before the pipe is pulled, heavy colloidal solid phase mud is selected, the re-expansion speed is slowed down, the mud is fully emulsified with the quicksand, the quicksand is suspended in the hole, and the adsorption of the quicksand is eliminated. When laying the pipe, the quicksand flows out of the hole with the mud.

[0185] When laying the pipe in the strong viscosity stratum 11:

[0186] The strong viscosity stratum 11 is expanded, and the clay forms a block and remains in the hole, which is difficult to stir into mud. When laying the pipe, the mud block is accumulated and extruded, and the pipe is deformed.

[0187] The hole is cleaned once before laying the pipe, and the pipe deformation is small, and the pipe is qualified. If the pipe deformation is large, the pipe is pulled out for repair, and if the repair fails, the pipe is scrapped.

[0188] During the pipe laying construction process, when the hole is collapsed, the diameter is reduced, and the pipe is easily stuck due to the presence of a large amount of mud block in the hole:

[0189] Before the pipe is stuck, the back-dragging pressure gauge gradually rises, and when the needle rises, the back-dragging speed is temporarily paused or slowed down, and the amount of mud is increased, so that the pipe is prevented from being stuck. After the pipe is stuck, the bulldozer and excavator are adjusted to pull out the pipe. The hole is cleaned and the pipe is laid again.

[0190] Thus, the construction process of the quick-change re-expansion device and hole expanding method of the preferred embodiment is completed.

[0191] In combination Figure 9 , Figure 9 is a schematic view of the rotary joint structure of the preferred embodiment of the quick-change re-expansion device and hole expanding method of the present application. The structure of the re-expansion device in the present embodiment is described in detail:

[0192] In the present embodiment, the hole expanding drill bit 161 includes a drill bit body 1611 and a pulling member 1612; the drill bit body 1611 is used to rotate the hole; the pulling member 1612 is arranged at one end of the drill bit body 1611, the drill bit body 1611 is connected with the rotary joint 163 through the pulling member 1612, and the first connecting hole is arranged on the pulling member 1612.

[0193] The rotary joint 163 in the present embodiment includes a first connecting part 1631 and a second connecting part 1632. The first connecting part 1631 is connected with the pulling member 1612 at one end, the second connecting part 1632 is connected with the back-pulling drill rod 163 at one end, and the first connecting part 1631 and the second connecting part 1632 are rotationally connected;

[0194] The first connecting part 1631 comprises two oppositely arranged limiting members 16311 for clamping the opening, the limiting members 16311 are provided with second connecting holes corresponding to the first connecting holes, the pulling member 1612 is arranged in the clamped opening, and the pulling member 1612 is connected with the first connecting part 1631 through bolts.

[0195] The second connecting part 1632 of the rotary joint 163 in the embodiment is provided with a connecting groove 16321 for connecting the first connecting part 1631; the first connecting part 1631 further comprises a rotating member 16312 arranged in the connecting groove 16321, and the first connecting part 1631 is rotatably connected with the second connecting part 13242 through the rotating member 16312. The rotating member 1612 is detachably connected with the limiting member 16311 at one end through bolts.

[0196] In combination with Figure 10 , Figure 10 The second embodiment of the rotary joint structure of the quick-replaceable back-expanding device and the hole expanding method is shown in the figure. The second embodiment of the rotary joint of the application is as follows:

[0197] The rotary joint 5 in the embodiment comprises a first connecting part 51 and a second connecting part 52. The first connecting part 51 is connected with a pulling member at one end, the second connecting part 52 is connected with a back-pulling drill rod at one end, and the first connecting part 51 is rotatably connected with the second connecting part 52; wherein the first connecting part 51 comprises two oppositely arranged limiting members 511 for clamping the opening, and the limiting members 511 are connected with the pulling member through bolts. The size of the opening of the rotary joint 5 in the embodiment for clamping the hole expanding drill bit is adjustable, and the adaptability of the rotary joint 5 is improved.

[0198] In combination with Figure 11 and Figure 12 , Figure 11 The initial position structure of the rotary joint of the second embodiment of the quick-replaceable back-expanding device and the hole expanding method is shown in the figure. Figure 12 The extrusion position structure of the rotary joint of the second embodiment of the quick-replaceable back-expanding device and the hole expanding method is shown in the figure.

[0199] In the embodiment, the first connecting part 51 of the rotary joint 5 comprises a limiting piece 511, a fixed seat 515 and an elastic piece 5153; one end of the limiting piece 511 is provided with an adjusting rod 512, and the adjusting rod 512 is provided with a limiting block 513 close to one end of the clamping opening. The fixed seat 515 is fixedly connected with one end of the second connecting part 52, and the fixed seat 515 is provided with a limiting groove 5151a for accommodating the adjusting rod 512, and the opening of the limiting groove 5151a is provided with a stop block 5151b. The elastic piece 5153 is arranged between the limiting block 513 and the stop block 5151b, and the elastic piece is used for extruding the limiting block 513, thereby improving the stability of the connection between the rotary joint 5 and the reaming drill bit.

[0200] Further, the two groups of limiting pieces 511 in the embodiment are adjustably connected with the fixed seat 515, further improving the adjustment range of the opening of the clamping reaming drill bit, and improving the practicability of the rotary joint in the embodiment.

[0201] In combination Figure 13 and Figure 14 , Figure 13 is a first fixed piece structure schematic view of a second embodiment of a quick replacement back reaming device and a reaming method of the application, Figure 14 is a second fixed plate structure schematic view of the second embodiment of the quick replacement back reaming device and the reaming method of the application.

[0202] The fixed seat 515 in the embodiment comprises a first fixed piece 5151 and a second fixed plate 5152 which are assembled together; the first fixed piece 5151 is fixedly connected with the second connecting part, the limiting groove 5151a is arranged on the side of the first fixed piece 5151 away from the first connecting part 51, and the side of the first fixed piece 5151 away from the first connecting part 51 is further provided with a first fixed hole 5151c; the second fixed plate 5152 is arranged on the side of the first fixed piece 5151 away from the first connecting part 51, and the second fixed plate 5152 is located between the two limiting pieces 511, the second fixed plate 5152 is provided with a second fixed hole 5152a matched with the first fixed hole 5151c, and the first fixed piece 5151 and the second fixed plate 5152 are fixedly connected by a fastener.

[0203] In addition, in the embodiment, the limiting piece 511 is further provided with a protective plate 514 away from the clamping opening, and the structure of the protective plate 514 is matched with the outer ring structure of the fixed seat 515.

[0204] Preferably, the protective plate 514 in the embodiment is of an arc structure, and the fixed seat 515 is provided with a avoiding notch 5154 for embedding the protective plate 514. This structure design improves the contact area of the fixed seat 515 and the limiting piece 511, and improves the stability of the overall structure of the rotary joint 5.

[0205] The elastic member 5153 of the rotary joint 5 in the embodiment includes an initial position and a pressed position. When the elastic member 5153 is in the initial position, the distance between the two limit members 511 in the rotary joint 5 is smaller than the distance between the two limit members 511 in the rotary joint 5 when the elastic member 5153 is in the pressed position.

[0206] When connecting the drag member of the fixed reaming drill bit, the two limit members 511 are relatively far away, so that the elastic member 5153 is deformed from the initial position to the pressed position; when the opening distance between the two limit members 511 is greater than the width of the drag member of the reaming drill bit, the drag member of the reaming drill bit is placed in the opening between the two limit members 511, and the limit members 511 correspond to the connecting holes of the drag member; then the elastic member 5153 is driven to drive the two limit members 511 to approach each other under the elastic recovery, until the drag member is clamped; finally, the limit members 511 and the drag member are fastened and connected by the fastening bolts.

[0207] On the basis of the first embodiment, by setting the rotary joint 5 with adjustable clamping opening size, the adaptability of the rotary joint 5 is improved, different sizes of reaming drill bits can be connected and fixed, and the practicability of the trenchless horizontal directional drilling pipe laying construction device is improved.

[0208] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application, and those skilled in the art can make various modifications and decorations without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application is subject to the scope defined by the claims.

Claims

1. A quick-change reaming device for reaming a pilot hole, characterized in that, The quick-change reaming device comprises: a reamer connected to one end of the drill rod for expanding the diameter of the guide hole; a pullback drill rod connected to the other end of the reamer, the other end of the pullback drill rod extending out of the guide hole away from the drilling machine for pulling back the drill rod; and a rotary joint arranged between the reamer and the pullback drill rod for adjusting the rotation direction of the pullback drill rod; the reamer comprises a reamer body for rotating reaming; and a pulling member arranged at one end of the reamer body, the reamer body being connected to the rotary joint through the pulling member; the rotary joint comprises a first connecting part connected to the pulling member and a second connecting part connected to the pullback drill rod, the first connecting part being rotationally connected to the second connecting part; wherein the first connecting part comprises two limit members arranged oppositely and forming a clamping opening, the limit members being connected to the pulling member through bolts, the pulling member being arranged in the clamping opening and being connected to the first connecting part through bolts; the second connecting part being provided with a connecting groove for connecting the first connecting part; the first connecting part further comprising a rotating member arranged in the connecting groove, the first connecting part being rotationally connected to the second connecting part through the rotating member; wherein one end of the rotating member extends out of the connecting groove, and one end of the rotating member is connected to the limit member through a bolt, the size of the clamping opening being adjustable, one end of the limit member being provided with an adjusting rod, the adjusting rod being provided with a limiting block near the center of the clamping opening, the first connecting part further comprising: a fixed seat fixedly connected to one end of the second connecting part, the fixed seat being provided with a limiting groove for accommodating the adjusting rod, the opening of the limiting groove being provided with a stop block, both the limit members and the fixed seat being adjustably connected; and a resilient member arranged between the limiting block and the stop block, the resilient member being used for pressing the limiting block, the fixed seat comprising: a first fixed member fixedly connected to the second connecting part, the limiting groove being arranged on the side of the first fixed member away from the first connecting part, and the side of the first fixed member away from the first connecting part being further provided with a first connecting hole; and a second fixed plate arranged on the side of the first fixed member away from the first connecting part and located between the two limit members, the second fixed plate being provided with a second connecting hole matched with the first connecting hole, the first fixed member and the second fixed plate being fixedly connected through a fastener.

2. The quick-change decompounding device according to claim 1, characterized in that one end of the limit member away from the clamping opening is further provided with a protective plate, the structure of the protective plate being matched with the outer structure of the fixed seat.

3. A method of reaming, characterized by, The application discloses a method for drilling and laying a pipeline in a stratum, and relates to the technical field of drilling and laying a pipeline. S3: the reaming device performs reaming construction, and the S3 comprises: S31: calculating a reaming diameter, The final reaming diameter is calculated according to the formula: D1=K1xD, wherein D1 is the diameter of the drilled hole suitable for laying a finished product pipe, D is the outer diameter of the finished product pipe, and K1 is an empirical coefficient, and the value of K1 is between 1.2 and 1.

5. S32: after the guide hole is formed, the guide drill bit is removed, a reaming drill bit is connected to the other end of the reaming drill bit, and the reaming drill bit is connected to a back-pulling drill rod to perform reaming drilling construction through the back-pulling drill rod; The reaming drill bit starts reaming along the guide hole from the position where the guide drill bit is pulled out until the guide hole is expanded to the target hole diameter. S33: when the small hole of the reaming drill bit can normally spray mortar, reaming is started. S34: the reaming drill bit starts reaming along the guide hole from the position where the guide drill bit is pulled out until the guide hole is expanded to the target hole diameter. S4: pipe laying construction: The drill rod is connected to the reaming drill bit, and the other end of the reaming drill bit is connected to a pipe pulling head to connect a pipeline. The reaming drill bit and the pipe pulling head are connected through a single-acting joint, the single-acting joint is used for preventing the pipeline from rotating together with the reaming drill bit, so that the pipeline can be smoothly back-acted. The laid pipeline is a steel pipe, and the steel pipe is connected with a recyclable grouting pipe at one end close to the reaming drill bit.

4. The method of reaming according to claim 3, wherein, The S34 comprises: S341: if the drill rod is stuck during drilling, then: S3411: the reaming drill bit is stuck due to collision with the underground pipeline, the reaming drill bit is withdrawn, the drill rod is pulled back, the drilling machine is shifted, and the guide hole is reformed; S3412: if a brick or a stone in the miscellaneous fill is stuck, a loosening torque is applied, the drill bit is rotated, and the reaming is slowly performed; if a large stone or a concrete block in the miscellaneous fill is stuck, the drill bit is withdrawn, the drilling machine is shifted, or the stone is dug out, and the reaming is continued; S3413: if the reaming drill bit is stuck due to a hard clay layer during reaming operation, the reaming speed is slowed down, the amount of mud is increased, and one drill rod is back-acted; S3414: if the reaming drill bit is stuck due to collision with a tree root, a loosening torque is applied, the reaming is slowly performed after the tree root is passed, the reaming is performed again after the tree root is crushed, and the tree root is crushed to prevent obstacles during pipe laying.

5. The method of reaming according to claim 3, wherein, The S34 further comprises: S342: if the guide hole is shrunk during drilling, the drill rod is removed, water in the hole flows out from the drill rod, a solid-phase mud is selected to protect the wall of the hole, the pressure in the hole is balanced, and the formed hole is maintained; or a reamer with one more stage is used to perform reaming, the hole is cleaned, and a pipe is laid; a PE pipe or a PVC pipe with high hardness and high lateral pressure resistance is selected.

6. The method of reaming according to claim 3, wherein, An entry point is arranged in the lower digging area, and an exit point is arranged in the upper digging area, and a straight line direction between the entry point and the exit point is a guide trajectory; Along the guide trajectory, a length of the lower digging area is L1', a length of the extension area is L2', and a length of the upper digging area is L3', The drilling trajectory comprises a first curve part arranged in the lower digging area, a straight line part arranged in the extension area, and a second curve part arranged in the upper digging area, the first curve part is arranged opposite to the second curve part at two ends of the straight line part, one end of the first curve part is connected with the entry point, and the other end is communicated with one end of the straight line part, one end of the second curve part is connected with the entry point, and the other end is communicated with the other end of the straight line part; A length of the first curve part projected on the ground is L1, a length of the straight line part projected on the ground is L2, a length of the second curve part projected on the ground is L3, a depth of the movement trajectory of the guide drill bit in the stratum is H1, an angle between the first curve part and the stratum surface is α1, and a curvature radius of the first curve part is R1, L1= ，α1= ； An angle between the second curve part and the stratum surface is α2, and a curvature radius of the second curve part is R2, L3= ，α2= ； When the L1 is less than L1', and the L3 is less than L3', the construction device drills and lays pipes according to the drilling trajectory.

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