Construction method of a new type of rotary jet grouting expanded anchor rod or cable

Abstract

The present invention provides a construction method for a new type of jet-grouted expanded anchor rod or cable. The present invention utilizes a pre-set first jet-grouted expanded body to form a limiting platform that can be abutted against, thereby forcing the continuously inserted cable part to be gradually coiled and arranged in the second jet-grouted expanded body. After the second jet-grouted expanded body solidifies, the bonding force between the cable part and the second jet-grouted expanded body is stronger and not easily separated; when the jet-grouted expanded body and the second jet-grouted expanded body are arranged without intervals, that is, they are abutted against each other, the second jet-grouted expanded body abuts against the bottom surface of the jet-grouted expanded body, further increasing the anchoring force of the anchoring part.

Description

Technical Field

[0001] The present invention relates to the construction technology field of geotechnical engineering, and particularly relates to a construction method for a new type of jet-grouted enlarged anchor rod or cable. Background Art

[0002] An anchor rod is an anchoring system that transfers tensile force through the rod body to stable rock or soil layers. One end of the rod body is fixed in the soil layer (or rock layer) inside the slope or foundation, and the other end is connected to the engineering structure. The anchoring force of the soil layer (or rock layer) is used to balance the external force acting on the building or structure, thereby maintaining the stability of the structure. When the rod body material is steel strand or high-strength steel wire bundle, it is also called a cable. To improve the pull-out bearing capacity of the anchor rod in the soil layer, one method is to locally increase the diameter of the anchor rod at the end of the anchor rod to form an enlarged head anchorage section, thereby increasing the frictional resistance and end resistance between the anchorage section and the soil layer.

[0003] The biggest difficulty of the end enlarged head anchor rod lies in the on-site construction of the enlarged head anchorage section:

[0004] (1) When using the jet-grouting method for enlarged head construction, the jet-grouting drill rod needs to extend horizontally and obliquely to the bottom of the anchor hole for jet-grouting. Due to the self-weight of the jet-grouting drill rod and the swivel head and other factors, it is easy to cause the deviation of the forming position of the jet-grouted enlarged body. Seriously, it may even cause the subsequent anchor rod to be unable to be inserted into the jet-grouted enlarged body.

[0005] (2) The jet-grouted enlarged body is actually a cement-soil formed by cutting and mixing cement slurry, water, and in-situ soil, and forms a cement-soil enlarged body after a certain period of curing. Different from the traditional equal-section anchor rod that can be cleaned after the drilling is completed to ensure the grouting quality, when the end enlarged head anchor rod is just constructed, it is generally impossible to clean the anchor hole, otherwise the clear water used for cleaning will dilute the cement-soil at the enlarged head, which will not only reduce the construction quality of the enlarged head, but also easily cause the collapse of the enlarged head.

[0006] At the same time, the anchor rod body can have good corrosion resistance only when it is completely wrapped by cement slurry. Inserting the anchor rod body into the anchor hole without cleaning will cause the anchor rod body to not be completely wrapped by cement slurry, and be partially wrapped by cement-soil or mixed with mud blocks, resulting in local corrosion of the anchor rod body and seriously weakening its long-term use safety. Summary of the Invention

[0007] The purpose of the present invention is to provide a construction method for a new type of jet-grouted enlarged anchor rod or cable to solve at least one of the above technical problems existing in the prior art. This application is a divisional application of the invention patent application with the application date of March 9, 2023, the application number of "2023102215257", and the name of "A Construction Method for a Jet-Grouted Enlarged Anchor Rod or Cable".

[0008] To solve the above technical problems, a construction method of a new type of jet grouting expanded anchor rod or cable provided by the present invention includes the following steps:

[0009] S10. Along the side wall of the foundation pit or slope, obliquely drive the casing into the soil body to a set depth;

[0010] S20. Place the jet grouting drill rod into the top end of the casing. After the bottom end of the jet grouting drill rod extends out of the bottom end of the casing, continue to drill until reaching the set bottom position of the enlarged head;

[0011] A positioner is sleeved on the part of the jet grouting drill rod inside the casing to prevent the jet grouting drill rod from being offset;

[0012] S30. Through the jet head at the bottom end of the jet grouting drill rod, inject clear water and neat cement slurry into the soil body while rotating. The clear water and neat cement slurry cut the surrounding soil body and mix with the loosened soil body cut to form cement soil;

[0013] During the jet grouting process, gradually withdraw the jet grouting drill rod until the jet head retracts into the casing; the cement soil forms a jet grouting expanded body with a diameter larger than the diameter of the casing at the bottom of the casing (after curing, it forms the above-mentioned enlarged head);

[0014] Then pull out the jet grouting drill rod from the casing;

[0015] S40. Place the grouting pipe into the top end of the casing until the bottom end of the casing (i.e., the top of the enlarged head); then inject neat cement slurry into the casing through the grouting pipe until all the slurry in the casing is replaced by neat cement slurry;

[0016] S50. Continue to drill the casing until the bottom end of the casing extends into the bottom of the jet grouting expanded body; during the drilling process, the grouting pipe moves synchronously with the casing, and continuously inject neat cement slurry into the casing through the grouting pipe;

[0017] S60. Place the anchor rod or cable into the casing until the bottom end of the anchor rod or cable extends into the bottom of the jet grouting expanded body;

[0018] S70. Gradually pull out the casing, and at the same time inject neat cement slurry through the grouting pipe to ensure that the anchor rod or cable is completely wrapped by neat cement slurry.

[0019] Further, it further includes the step:

[0020] S80. After the casing is pulled out for 3 to 4 hours, perform secondary split grouting through the grouting pipe.

[0021] Further, the anchor rod is a capsule-type anchor rod; in step S70, while pulling out the casing, inject neat cement slurry into the outside of the capsule through the grouting pipe;

[0022] After the casing is pulled out, immediately inject neat cement slurry into the capsule to make the capsule full.

[0023] Furthermore, the anchor rod is a capsule-type anchor rod; in step S80, after the casing is pulled out for 3 to 4 hours, while secondary splitting grouting is carried out through the grouting pipe, pressure grouting is carried out into the capsule bag.

[0024] Furthermore, in step S10, the casing is obliquely driven into the soil body by means of mud drilling.

[0025] Furthermore, the specification of the casing is φ146×8mm.

[0026] Furthermore, the jet grouting drill pipe is a φ75×5mm drill pipe.

[0027] Furthermore, the water-cement ratio of the pure cement slurry is 0.6 to 0.8.

[0028] Furthermore, the length of the capsule bag is not greater than the length of the jet grouting enlarged body, and the diameter of the capsule bag is greater than the outer diameter of the casing.

[0029] Furthermore, in step S20, a plurality of the positioners are sleeved on the part of the jet grouting drill pipe inside the casing at intervals.

[0030] Among them, the positioner is an annular body, the middle through hole of the annular body is adapted to the outer diameter of the jet grouting drill pipe, and the outer diameter of the annular body is adapted to the inner diameter of the casing.

[0031] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0032] A construction method of a novel jet grouting enlarged body anchor rod or cable provided by the present invention has the following advantages and beneficial effects:

[0033] 1. The present invention adopts the casing drilling process. When forming a hole, the casing can effectively protect the hole wall of the anchor hole and prevent the occurrence of hole collapse.

[0034] 2. Positioners are arranged at intervals on the jet grouting drill pipe, and the relatively rigid casing is used to limit the axial position of the jet grouting drill pipe, so that the jet grouting head can form an enlarged head through precise jet grouting at the designed position.

[0035] 3. After the jet grouting enlarged body construction is completed, by injecting pure cement slurry into the casing, the slurry in the casing is completely replaced, ensuring that when the casing is subsequently drilled to the enlarged head part, the cement soil at the jet grouting enlarged body (i.e., the enlarged head) will not be diluted by the slurry in the casing. At the same time, it can also ensure that when the anchor rod is inserted into the casing subsequently, the anchor rod is completely wrapped by the pure cement slurry, which can not only make the anchor rod body and the jet grouting enlarged body form an integral body, but also effectively guarantee the corrosion resistance of the anchor rod.

[0036] 4. After the enlarged head is formed, the casing can be continuously drilled, so that the conventional diameter section and the enlarged head section of the anchor hole can be effectively connected as a whole. The supplementary grouting and secondary split grouting carried out after the casing is pulled out can enable a good common stress system to be formed among the jet-grouted enlarged body, pure cement slurry, and the anchor rod body, effectively improving the anti-pulling capacity of the anchor rod (cable).

[0037] In summary, the present invention forms an enlarged body through the traditional jet-grouting method, combines the casing drilling process, and optimizes the construction process and grouting sequence. As a result, not only can the anchor rod body and the jet-grouted enlarged head effectively form an integral structure, but also it can be ensured that the anchor rod body is completely wrapped by pure cement slurry, effectively solving the problem of poor corrosion resistance of the jet-grouted enlarged head anchor. Description of the Drawings

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1a It is a schematic diagram of step S10 in the construction method of the novel jet-grouted enlarged body anchor rod or cable provided in Embodiment 1 of the present invention;

[0040] Figure 1b It is a schematic diagram of step S20 in the construction method provided in Embodiment 1;

[0041] Figure 1c It is a schematic diagram of step S30 in the construction method provided in Embodiment 1;

[0042] Figure 1d It is a schematic diagram of the structure when inserting the grouting pipe into the casing in step S40 of the construction method provided in Embodiment 1;

[0043] Figure 1e It is a schematic diagram of the structure after all the mud in the casing is replaced with pure cement slurry in step S40 of the construction method provided in Embodiment 1;

[0044] Figure 1f It is a schematic diagram of step S50 in the construction method provided in Embodiment 1;

[0045] Figure 1g It is a schematic diagram of the structure when the anchor rod or cable is placed into the casing in step S70 of the construction method provided in Embodiment 1;

[0046] Figure 2 It is a schematic diagram of the structure when the capsule anchor rod is placed into the casing in the construction method provided in Embodiment 1;

[0047] Figure 3 In the prior art, it is a schematic structural diagram of the jet grouting body being offset due to the self-weight bias of the jet grouting drill pipe and the jet grouting head;

[0048] Figure 4 It is a schematic layout structure diagram of the first jet grouting enlarged body in Embodiment 2;

[0049] Figure 5 It is a schematic layout structure diagram of the second jet grouting enlarged body in Embodiment 2;

[0050] Figure 6 It is a schematic layout structure diagram of the anchor in Embodiment 2.

[0051] Reference numerals:

[0052] 10 - casing; 11 - grouting pipe; 20 - jet grouting body; 21 - first jet grouting enlarged body; 22 - second jet grouting enlarged body; 30 - jet grouting drill pipe; 31 - jet grouting head; 40 - locator; 50 - anchor rod; 51 - bladder; 60 - anchor; 61 - anchor rod part; 62 - anchor cable part. Detailed implementation manners

[0053] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0055] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0057] Embodiment 1

[0058] A construction method for a novel jet-grouted and enlarged anchor rod or cable provided in this embodiment specifically includes the following steps:

[0059] S10. As shown in Figure 1a , the casing 10 is obliquely driven into the soil along the side wall of the foundation pit or slope to a set depth by using the mud drilling method;

[0060] The specification of the casing 10 is preferably φ146×8mm.

[0061] S20. As shown in Figure 1b , the jet-grouting drill pipe 30 is placed into the casing 10 from the top end of the casing 10. After the bottom end of the jet-grouting drill pipe 30 extends out of the bottom end of the casing 10, it continues to drill until the set bottom position of the enlarged head is reached;

[0062] A locator 40 is sleeved on the part of the jet-grouting drill pipe 30 inside the casing 10 to prevent the jet-grouting drill pipe 30 from being offset;

[0063] Preferably, a plurality of the locators 40 are sleeved at intervals on the part of the jet-grouting drill pipe 30 inside the casing 10. The locator 40 is an annular body. The middle through hole of the annular body is adapted to the outer diameter of the jet-grouting drill pipe 30, and the outer diameter of the annular body is adapted to the inner diameter of the casing 10.

[0064] The jet-grouting drill pipe 30 is a drill pipe with a diameter of φ75×5mm.

[0065] S30. As shown in Figure 1c , water and neat cement slurry are injected into the soil by rotating the jet head 31 at the bottom end of the jet-grouting drill pipe 30 while rotating. The water and neat cement slurry cut the surrounding soil and are mixed with the fallen soil to form cement soil;

[0066] During the jet-grouting process, the jet-grouting drill pipe 30 is gradually withdrawn until the jet head 31 retracts into the casing 10; the cement soil forms a jet-grouted and enlarged body 20 with a diameter larger than that of the casing 10 at the bottom of the casing 10 (which forms the above-mentioned enlarged head after curing);

[0067] Then the jet-grouting drill pipe 30 is pulled out of the casing 10;

[0068] The water-cement ratio of the neat cement slurry is 0.6 to 0.8.

[0069] S40. As shown in Figure 1d , the grouting pipe 11 is placed into the casing 10 from the top end of the casing 10 until the bottom end of the casing 10 (i.e., the top of the enlarged head); as shown in Figure 1eAs shown, pure cement slurry is then injected into the casing 10 through the grouting pipe 11 until all the soil slurry in the casing 10 is replaced by pure cement slurry; the water-cement ratio of the pure cement slurry is 0.6 - 0.8.

[0070] S50. As Figure 1f shown, the casing 10 is continuously drilled until the bottom end of the casing 10 extends into the bottom of the jet grouting enlarged body 20; during the drilling process, the grouting pipe 11 moves synchronously with the casing 10, and pure cement slurry is continuously injected into the casing 10 through the grouting pipe 11;

[0071] S60. Place the anchor rod 50 or cable into the casing 10 until the bottom end of the anchor rod 50 or cable extends into the bottom of the jet grouting enlarged body 20;

[0072] S70. As Figure 1g shown, gradually pull out the casing 10, and at the same time inject pure cement slurry through the grouting pipe 11 to ensure that the anchor rod 50 or cable is completely wrapped by pure cement slurry.

[0073] Furthermore, it also includes the steps:

[0074] S80. 3 - 4 hours after the casing 10 is pulled out, secondary split grouting is carried out through the grouting pipe 11.

[0075] More preferably, referring to Figure 2 shown, the anchor rod 50 is a capsule-type anchor rod; in step S70, while pulling out the casing 10, pure cement slurry is injected into the outside of the capsule 51 through the grouting pipe 11; after the casing 10 is pulled out, pure cement slurry is immediately injected into the capsule 51 to fill the capsule 51. In step S80, 3 - 4 hours after the casing 10 is pulled out, while secondary split grouting is carried out through the grouting pipe 11, pressure grouting is carried out into the capsule 51.

[0076] The length of the capsule 51 is not greater than the length of the jet grouting enlarged body 20, and the diameter of the capsule 51 is greater than the outer diameter of the casing 10.

[0077] A construction method for a novel jet grouting enlarged body 20 anchor rod 50 or cable provided by the present invention has the following advantages and beneficial effects:

[0078] 1. The present invention effectively solves the problem of hole collapse during the construction of the anchor rod 50. In some poor soil layers such as sandy layers and gravel, hole collapse easily occurs during the construction of the enlarged head anchor rod, and the rod body of the anchor rod 50 cannot be smoothly inserted into the anchor hole, resulting in the inability to continue the construction of the anchor rod 50. The present invention adopts the casing 10 drilling process, and the casing 10 can effectively protect the hole wall of the anchor hole during hole formation, preventing hole collapse.

[0079] 2. As Figure 3As shown in the figure, in the prior art, when jet grouting construction is carried out on the expanded section of the anchor rod 50, when the jet grouting drill rod 30 extends horizontally and obliquely to the bottom of the anchor hole for jet grouting, vertical bending will occur due to the self-weight of the jet grouting drill rod 30 and the jet grouting head 31, and it is often impossible to accurately be in the center position of the anchor hole in the horizontal direction, resulting in serious deviation of the position of the formed jet grouted expansion body 20, and even causing the rod body of the anchor rod 50 to be unable to be inserted into the expansion body, thus greatly reducing the quality of the anchor rod 50.

[0080] In this application, positioners 40 are arranged at intervals on the jet grouting drill rod 30, and the axial position of the jet grouting drill rod 30 is restricted by using the casing 10 with relatively large stiffness, so that the jet grouting head 31 can form an enlarged head through precise jet grouting at the designed position.

[0081] 3. In the prior art, it is impossible to clean the hole during the construction of the enlarged head anchor rod, otherwise the cement soil at the expanded part will be diluted, not only reducing the construction quality of the enlarged head, but also easily causing collapse of the hole at the enlarged head. If grouting is directly carried out without cleaning the hole, since the specific gravity of the cement soil is equivalent to that of the pure cement slurry, the injected cement slurry cannot completely displace the cement soil around the rod body, resulting in partial wrapping of the rod body by the cement soil slurry, and even being mixed with mud blocks generated during the jet grouting construction of the expanded section, which will cause local corrosion of the rod body.

[0082] After the construction of the jet grouted expansion body 20 in this application is completed, by injecting pure cement slurry into the casing 10, the slurry in the casing 10 is completely displaced, ensuring that when the casing 10 is subsequently drilled into the enlarged head part, the cement soil at the jet grouted expansion body 20 (i.e., the enlarged head) will not be diluted by the slurry in the casing 10. At the same time, it can also ensure that when the anchor rod 50 is inserted into the casing 10 subsequently, the anchor rod 50 is completely wrapped by the cement slurry, which can not only make the rod body of the anchor rod 50 form an integral body with the jet grouted expansion body 20, but also effectively guarantee the corrosion resistance of the anchor rod 50.

[0083] 4. After the enlarged head is formed, continuing to drill the casing 10 can effectively connect the conventional diameter section and the enlarged head section of the anchor hole into an integral body. The supplementary grouting and secondary split grouting carried out after the casing 10 is pulled out can form a good common stress system among the jet grouted expansion body 20, the pure cement slurry, and the rod body of the anchor rod 50, effectively improving the anti-pulling capacity of the anchor rod 50 (or cable).

[0084] In summary, the present invention forms an expansion body through the traditional jet grouting method, combines the casing 10 drilling process, and optimizes the construction process and grouting sequence, so that not only can the rod body of the anchor rod 50 and the jet grouted enlarged head effectively form an integral structure, but also it can ensure that the rod body of the anchor rod 50 is completely wrapped by the pure cement slurry, effectively solving the problem of poor corrosion resistance of the jet grouted enlarged head anchor rod 50.

[0085] Embodiment 2

[0086] A construction method of a novel jet-grouting expanded body anchor or cable provided in this embodiment is basically the same as that in Embodiment 1. The differences are as follows. Specifically, it includes the following steps:

[0087] S10. As Figure 1a shown, adopt the mud drilling method, and obliquely drive the casing 10 into the soil along the side wall of the foundation pit or slope to a set depth;

[0088] S20. As Figure 4 shown, place the jet-grouting drill pipe 30 from the top end of the casing 10. After the bottom end of the jet-grouting drill pipe 30 extends out of the bottom end of the casing 10, continue to drill and exceed the set bottom position of the enlarged head; A locator 40 is sleeved on the part of the jet-grouting drill pipe 30 inside the casing 10 to prevent the jet-grouting drill pipe 30 from being offset;

[0089] Inject pure cement slurry into the soil by rotating the jetting head 31 at the bottom end of the jet-grouting drill pipe 30 while rotating. The pure cement slurry cuts the surrounding soil, and the pure cement slurry is mixed with the fallen soil to form cement soil; During the jet-grouting process, gradually withdraw the jet-grouting drill pipe 30, and thus form the first jet-grouting enlarged body 21 obliquely below the set enlarged head;

[0090] S30. As Figure 5 shown, after the first jet-grouting enlarged body 21 is consolidated, inject pure cement slurry into the soil by the jetting head 31 at the bottom end of the jet-grouting drill pipe 30. During the jet-grouting process, gradually withdraw the jet-grouting drill pipe 30, and the cement soil forms the second jet-grouting enlarged body 22 at the top of the first jet-grouting enlarged body 21 and obliquely below the set enlarged head;

[0091] S40. Inject pure cement slurry into the soil through the jetting head 31 to form a jet-grouting enlarged body 20 (which forms the above-mentioned enlarged head after curing) with a diameter larger than that of the casing 10 at the bottom of the casing 10; The jet-grouting enlarged body 20 and the second jet-grouting enlarged body 22 are arranged at intervals or non-intervals;

[0092] Then pull out the jet-grouting drill pipe 30 from the casing 10;

[0093] S50. Place the grouting pipe 11 from the top end of the casing 10 until the bottom end of the casing 10 (i.e., the top of the enlarged head); Then inject pure cement slurry into the casing 10 through the grouting pipe 11 until all the mud slurry in the casing 10 is replaced by pure cement slurry;

[0094] S60. Continue to drill the casing 10 until the bottom end of the casing 10 passes through the jet-grouting enlarged body 20 until the bottom of the second jet-grouting enlarged body 22; During the drilling process, the grouting pipe 11 moves synchronously with the casing 10, and continuously inject pure cement slurry into the casing 10 through the grouting pipe 11;

[0095] S80. As Figure 6As shown, the anchor 60 is inserted into the top of the casing 10. The anchor 60 includes an anchor rod portion 61 and a cable portion 62; the cable portion 62 is made of flexible steel strands; by squeezing both ends of the cable portion 62, the cable portion 62 can be forced to bend.

[0096] The bottom end of the cable portion 62 passes through the second jet grouting enlarged body 22 and abuts against the top of the first jet grouting enlarged body 21; then the cable portion 62 is continuously fed downward; further, through the anchor rod portion 61, the first jet grouting enlarged body 21 and the casing 10, the middle and lower parts of the cable portion 62 are forced to coil inside the second jet grouting enlarged body 22.

[0097] The bottom end of the cable portion 62 extends from the bottom of the jet grouting enlarged body 20 and is fixedly connected to the top end of the cable portion 62 extending from the top of the second jet grouting enlarged body 22.

[0098] S90. Gradually pull out the casing 10, and at the same time inject pure cement slurry through the grouting pipe 11 to ensure that the parts of the anchor rod portion 61 and the cable portion 62 outside the second jet grouting enlarged body 22 are completely wrapped by the pure cement slurry.

[0099] S100. After the casing 10 is pulled out for 3 to 4 hours, perform secondary split grouting through the grouting pipe 11.

[0100] In order to ensure that the flexible cable portion 62 can be smoothly inserted into the bottom of the casing 10, an auxiliary rod can be used for traction. For example, the free end of the cable portion 62 is fixed to the bottom end of the grouting pipe 11, so that the cable portion 62 extends into the bottom of the casing 10 along with the grouting pipe 11. When both ends of the cable portion 62 are squeezed by the anchor rod portion 61 and the first jet grouting enlarged body 21 respectively, the casing 10 plays a limiting role at the same time, forcing the cable portion 62 to coil inside the casing 10; preferably, when the pure cement slurry is in a semi-solidified state, the casing 10 is gradually pulled out, and the semi-solidified pure cement slurry can play a role in shaping and restricting the cable portion 62.

[0101] Compared with Embodiment 1, this embodiment utilizes the pre-set first jet grouting enlarged body 21 to form a limiting platform that can be abutted, so as to force the continuously inserted cable portion 62 to gradually coil and be arranged inside the second jet grouting enlarged body 22. After the second jet grouting enlarged body 22 solidifies, the bonding force between the cable portion 62 and the second jet grouting enlarged body 22 is stronger and not easily separated; when the jet grouting enlarged body 20 and the second jet grouting enlarged body 22 are arranged in a non-spacing manner and abut against each other, the second jet grouting enlarged body 22 abuts against the bottom surface of the jet grouting enlarged body 20, further increasing the anchoring force of the anchoring portion 61.

[0102] When the jet grouting enlarged body 20 and the second jet grouting enlarged body 22 are arranged at intervals, the second jet grouting enlarged body 22 often has the problems of sagging or offset in the above-mentioned existing technologies. The second jet grouting enlarged body 22 is arranged at a certain angle with the jet grouting enlarged body 20, and this structure can also increase the anchoring force between the anchoring part 61 and the jet grouting enlarged body 20.

[0103] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A construction method for a new type of jet-grouting expanded body anchor rod or cable, characterized in that, It includes the following steps: S10. Adopt the mud drilling method, and obliquely drive the casing into the soil along the side wall of the foundation pit or slope to a set depth; S20. Place the jet grouting drill pipe into the casing from the top end of the casing. After the bottom end of the jet grouting drill pipe extends out of the bottom end of the casing, continue to drill and exceed the set bottom position of the enlarged head; A positioner is sleeved on the part of the jet grouting drill pipe inside the casing to prevent the jet grouting drill pipe from being offset; Inject pure cement slurry into the soil by rotating the jet head at the bottom end of the jet grouting drill pipe while rotating. The pure cement slurry cuts the surrounding soil, and the pure cement slurry is mixed with the fallen soil to form cement soil; During the jet grouting process, gradually withdraw the jet grouting drill pipe, and then form a first jet grouting enlarged body obliquely below the set enlarged head; S30. After the first jet grouting enlarged body is consolidated, inject pure cement slurry into the soil through the jet head at the bottom end of the jet grouting drill pipe. During the jet grouting process, gradually withdraw the jet grouting drill pipe, and the cement soil forms a second jet grouting enlarged body at the top of the first jet grouting enlarged body and obliquely below the set enlarged head; S40. Inject pure cement slurry into the soil through the jet head to form a jet grouting enlarged body with a diameter larger than the diameter of the casing at the bottom of the casing; The jet grouting enlarged body and the second jet grouting enlarged body are arranged at intervals or without intervals; Then pull out the jet grouting drill pipe from the casing; S50. Place the grouting pipe into the casing from the top end of the casing until the bottom end of the casing; Then inject pure cement slurry into the casing through the grouting pipe until all the muddy slurry in the casing is replaced by pure cement slurry; S60. Continue to drill the casing until the bottom end of the casing passes through the jet grouting enlarged body until the bottom of the second jet grouting enlarged body; During the drilling process, the grouting pipe moves synchronously with the casing, and continuously inject pure cement slurry into the casing through the grouting pipe; S80. Place the anchor from the top of the casing. The anchor includes a bolt part and a cable part; The cable part is made of flexible steel strands; By squeezing both ends of the cable part, the cable part can be forced to bend; The bottom end of the cable part passes through the second jet grouting enlarged body and abuts against the top of the first jet grouting enlarged body; Then continue to send the cable part downward; Then, through the bolt part, the first jet grouting enlarged body and the casing, the middle and lower parts of the cable part are forced to coil inside the second jet grouting enlarged body; The bottom end of the cable part extends into from the bottom of the jet grouting enlarged body and is fixedly connected to the top end of the cable part extending out of the top of the second jet grouting enlarged body; S90. Gradually pull out the casing, and at the same time inject pure cement slurry through the grouting pipe to ensure that the parts of the bolt part and the cable part outside the second jet grouting enlarged body are completely wrapped by pure cement slurry; S100. 3 to 4 hours after the casing is pulled out, perform secondary split grouting through the grouting pipe.

2. The construction method according to claim 1, characterized in that, Fix the free end of the cable part at the bottom end of the grouting pipe, so that the cable part extends into the bottom of the casing along with the grouting pipe; When both ends of the cable part are squeezed by the bolt part and the first jet grouting enlarged body respectively, the casing plays a limiting role at the same time, forcing the cable part to coil inside the casing.

3. The construction method according to claim 1, characterized in that, When the pure cement slurry is in a semi-solidified state, gradually pull out the casing, and the semi-solidified pure cement slurry plays a shaping and limiting role on the cable part.

4. The construction method according to claim 1, characterized in that, In step S20, multiple said positioners are sleeved on the part of the jet grouting drill pipe inside the casing at intervals.

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