CN110541424B

CN110541424B - Method for arranging grouting embedded pipe below dam plug body impervious wall construction

Info

Publication number: CN110541424B
Application number: CN201910970211.0A
Authority: CN
Inventors: 宗敦峰; 肖恩尚; 唐玉书; 刘保柱; 罗庆松; 陈小明; 赵明华; 罗蓓蓓
Original assignee: Sinohydro Foundation Engineering Co Ltd
Current assignee: Sinohydro Foundation Engineering Co Ltd
Priority date: 2019-10-12
Filing date: 2019-10-12
Publication date: 2020-08-07
Anticipated expiration: 2039-10-12
Also published as: CN110541424A

Abstract

The invention discloses a method for arranging a grouting embedded pipe below a weir plug body diaphragm wall, which comprises the following steps: forming a slotted hole of the barrier body impervious wall; hoisting the embedded pipes layer by layer through the cross beam to arrange the multilayer embedded pipes in the slotted holes layer by layer; when each layer of the embedded pipes is arranged below, simultaneously positioning a plurality of embedded pipes in the layer of the embedded pipes through an embedded pipe truss, and arranging the embedded pipe truss into the slotted hole along with the layer of the embedded pipes; wherein, pre-buried pipe truss includes: the device comprises a main frame for fixing a plurality of embedded pipes and a plurality of positioning frames fixedly connected with the main frame; the positioning frames extend along the width direction of the slotted holes and are in line contact with two side walls of the slotted holes respectively, so that the pre-embedded pipe truss arranged in the slotted holes along with the pre-embedded pipes can be prevented from being arranged downwards continuously due to the fact that the pre-embedded pipe truss touches a probe stone on the side walls of the slotted holes. The method can avoid the probe stones under the stratum condition of the damming body, quickly and smoothly underground set the embedded pipe, improve the survival rate of the embedded pipe and ensure the grouting quality of the curtain under the wall.

Description

Method for arranging grouting embedded pipe below dam plug body impervious wall construction

Technical Field

The invention relates to the field of water conservancy and hydropower engineering, in particular to a method for arranging a grouting embedded pipe below a weir plug body diaphragm wall in construction.

Background

The damming body is formed by earthquake collapse and landslide, and because the damming lake remediation is in need, the damming body remediation needs to take the working ideas of simultaneous research, simultaneous design and simultaneous remediation, and needs to implement danger removal and flood control projects such as damming body remediation as soon as possible. The damming body renovation is to carry out anti-seepage treatment and partial slope renovation on the damming body, the damming base and the bank slope at two sides, and the damming body anti-seepage treatment adopts the combination of anti-seepage wall and curtain grouting.

For the dam body, the prior treatment engineering experience mainly aims at removing and dredging water flow, but for the dam body with huge volume formed by super-huge collapse, the removal cost is very high, and a proper field is difficult to find near an engineering address for piling so many piled bodies, so if the dam body can be fully utilized, the dam body is directly formed by utilizing the dam body, the harm and the benefit can be removed, and the waste is changed into the valuable.

In the prior art, when the embedded pipe is arranged below, the survival rate of the embedded pipe is very low according to the past construction experience of the impervious wall of a complex stratum, and the method is generally adopted for repairing and grouting holes on a wall, so that not only is the time wasted and the construction cost improved, but also the concrete impervious wall is damaged. For the geological conditions of the weir plug body with large boulder content, large particle size and high hardness, the hole shape is difficult to control and the number of probe stones is large when the impervious wall is grooved, the embedded pipe positioning frame with the traditional outer frame being a rectangular frame is adopted, the hole wall or the probe stones are easy to touch when the embedded pipe positioning frame is arranged below the external frame, so that the embedded pipe cannot be smoothly arranged below the external frame, the unfavorable conditions cause great difficulty for the construction of the impervious wall, great challenge is provided for the prior construction technology, and no construction precedent exists at home and abroad in longitudinal view.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a method for arranging the lower part of the pre-buried pipe for grouting in the construction of the barrier body diaphragm wall, which can avoid the probe stone under the condition of the barrier body stratum, quickly and smoothly arrange the pre-buried pipe underground, improve the survival rate of the pre-buried pipe and ensure the grouting quality of the curtain under the wall.

In order to achieve the purpose, the method for arranging the grouting embedded pipe below the barrier dam body impervious wall comprises the following steps:

drilling and cleaning the hole by taking the axis of the barrier body impervious wall as a reference to form a slotted hole of the barrier body impervious wall;

after the slotted hole is formed, the pre-buried pipes are hung layer by layer through the cross beam so as to be arranged in the slotted hole layer by layer;

when each layer of embedded pipes is arranged below, the lower parts of the layers of embedded pipes are arranged in the slotted holes simultaneously, then a plurality of embedded pipes in the layers of embedded pipes are positioned simultaneously through an embedded pipe truss, and the embedded pipe truss is arranged in the slotted holes together with the layers of embedded pipes;

wherein the pre-buried pipe truss comprises: the length extension direction of the embedded pipe is parallel to the axial direction of the slotted hole and is used for fixing a main frame of a plurality of embedded pipes and a plurality of positioning frames fixedly connected with the main frame;

the positioning frames extend along the width direction of the slotted holes and are in line contact with two side walls of the slotted holes respectively, so that the pre-embedded pipe truss arranged in the slotted holes along with the pre-embedded pipes can be prevented from being arranged downwards continuously due to the fact that the pre-embedded pipe truss touches a probe stone on the side walls of the slotted holes.

Preferably, the plurality of positioning frames are arranged at intervals along the length direction of the main frame.

Preferably, the spacer includes: the first positioning frame is fixedly connected with the main frame and extends out of the main frame towards the direction of the side wall of the slotted hole, and the first positioning frame is provided with a first connecting beam in line contact with the side wall of the slotted hole; the second positioning frame is fixedly connected with the main frame and extends out of the main frame towards the other side wall of the slotted hole, and the second positioning frame is provided with a second connecting beam in line contact with one side wall of the slotted hole.

Preferably, the first connecting beam and the second connecting beam are both arc-shaped beams.

Wherein, the locating rack includes: an upper cantilever beam, one end of which is connected with the upper end of the main frame and extends along the width direction of the slotted hole; one end of the lower suspension beam is connected with the lower end of the main frame and extends along the width direction of the slotted hole; the two ends of the first connecting beam are respectively connected with one end of the upper overhanging beam and one end of the lower overhanging beam and are in line contact with one side wall of the slotted hole; and the two ends of the second connecting beam are respectively connected with the other end of the upper overhanging beam and the other end of the lower overhanging beam and are in line contact with the other side wall of the slotted hole.

Preferably, the main frame is provided with a plurality of gaps for sleeving the plurality of embedded pipes, and the plurality of gaps are arranged at intervals along the length direction of the main frame.

When the multilayer embedded pipes are arranged in the slotted holes layer by layer, the method comprises the following steps:

when the upper layer of embedded pipes are not positioned in the area where the reinforcement cage is positioned, corresponding embedded pipes in the two layers of embedded pipes which are adjacent up and down are fixedly connected together by a sleeve splicing welding method, so that the embedded pipes which are adjacent up and down can not be broken due to the occurrence of inflection points at the connection part when concrete is poured;

when the upper layer embedded pipes are located in the area where the reinforcement cage is located, corresponding embedded pipes in the two layers of the upper and lower adjacent embedded pipes are movably connected together through a long sleeve inserting method, so that when concrete is poured, the upper and lower adjacent embedded pipes can axially stretch out and draw back, and each embedded pipe below cannot be damaged due to floating of the reinforcement cage.

Wherein, through the sleeve method of splicing welding two adjacent buried pipes of upper and lower part together, include:

sleeving one end of a sleeve outside the top of the lower embedded pipe, extending the other end of the sleeve outside the lower embedded pipe, and fixedly welding the top of the lower embedded pipe and the sleeve together so that the sleeve provides a guiding effect for the lower adjacent upper embedded pipe;

the bottom of the upper embedded pipe arranged below is inserted into the sleeve from the other end of the sleeve through the guiding of the sleeve, and then the upper embedded pipe is fixedly connected with the sleeve.

Wherein, the method of pegging graft through the long sleeve links together two adjacent buried pipes from top to bottom includes:

the bottom of the upper embedded pipe arranged below is inserted into the sleeve from the other end of the sleeve through the guiding of the sleeve.

Preferably, the cross member includes: a beam main body; a plurality of lifting lugs are arranged on the beam main body at intervals along the length extension direction of the beam main body; the extending direction of the lifting lug is perpendicular to the length extending direction of the beam main body, and a plurality of lifting holes with different intervals are formed in the lifting lug.

Wherein, when hanging the buried pipe down through the crossbeam, still include following step: the embedded pipe is quickly hung on the hanging hole through the quick clamping assembly.

Preferably, the quick clamping assembly includes: the annular buckle is formed by connecting two semi-annular buckles together through a bolt; the two ends of the steel wire rope are respectively detachably connected with the outer sides of the two semi-annular buckles and penetrate through the lifting hole; the interval sets up the cover of embedded pipe is equipped with sleeve one end outer wall and follows a plurality of location muscle of embedded pipe radial protrusion outwards.

Preferably, the inner diameter of an annular formed by buckling the two semi-annular buckles is smaller than the inner diameter from the center of the embedded pipe to the outer side wall of the positioning rib.

Preferably, the semi-annular buckle comprises: one end of the first buckle is provided with a pin hole and is arc-shaped; and one end of the second buckle is connected with the other end of the first buckle through a bolt, and the other end of the second buckle is connected with the second buckle of the other half of the annular buckle through a bolt.

Preferably, the positioning frame further comprises: and the reinforcing beam is connected with the main frame at one end and the connecting beam at the other end.

Preferably, the plurality of positioning frames correspond to the plurality of notches on the main frame respectively.

Preferably, before forming the slot of the barrier seepage-proofing wall, the method also comprises the step of pretreating the formation of the barrier stratum to form a homogeneous formation.

Compared with the prior art, the method for arranging the grouting embedded pipe under the weir plug body diaphragm wall in the construction process has the following beneficial effects:

1. the method can be used for arranging the embedded pipe under the geological condition of the damming body with the maximum depth of the impervious wall exceeding 130m and the large content of boulders, effectively avoids the condition that the embedded pipe truss and the embedded pipe cannot be arranged due to the protruding probe stones on the side wall of the slotted hole in the arranging process, improves the survival rate of the embedded pipe, and ensures the grouting quality of the curtain under the wall.

2. According to the method, the embedded pipe truss which forms a line with the contact friction track of the side wall of the slotted hole is adopted for arranging and positioning the embedded pipe, so that the contact probability between the embedded pipe truss and the side wall of the slotted hole and the probe stone when the embedded pipe truss is arranged below the embedded pipe is greatly reduced, and the arrangement efficiency is improved.

3. According to the method, the sleeve guiding connection method is adopted to connect the upper embedded pipe and the lower embedded pipe which are adjacent to each other, so that the verticality of the embedded pipes is guaranteed, the embedded pipes are prevented from interfering with the reinforcement cage, and the survival rate of the embedded pipes is greatly improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Drawings

FIG. 1 is a schematic diagram showing the positions of a blast hole and upstream and downstream grouting holes in a pretreatment method for trenching construction of a weir plug body diaphragm wall;

FIG. 2 is a schematic illustration of the blast hole drilling and blasting process of the present invention;

FIG. 3 is a flow chart of the grouting hole grouting process of the present invention;

FIG. 4 is a schematic view of the present invention grouting a grouting hole by using a tube drawing method;

FIG. 5 is a schematic view of a floral tube of the present invention;

FIG. 6 is a diagram showing the ratio of grouting liquid used in grouting according to the present invention;

FIG. 7 is a schematic view of the placement of a buried pipe down a slotted hole of lesser axial length;

fig. 8 is a schematic structural view of a pre-buried pipe truss of the present invention;

fig. 9 is a partial perspective view of a pre-buried pipe truss of the present invention;

FIG. 10 is a front view of the main frame of the present invention;

FIG. 11 is a perspective view of a main frame of the present invention;

FIG. 12 is a left side view of the spacer of the present invention;

FIG. 13 is a schematic view of the pre-buried pipe of the present invention secured to a pre-buried pipe truss;

FIG. 14 is a schematic view of the socket insert welding method of the present invention connecting two adjacent pre-buried pipes;

FIG. 15 is a schematic structural view of a beam of the present invention;

FIG. 16 is a cross-sectional view of the beam body;

FIG. 17 is a schematic view of the clasp of the present invention in a closed position;

FIG. 18 is a schematic view of the clasp of the present invention in an open position;

figure 19 is a schematic view of the placement of a buried pipe down a slotted hole of greater axial length.

Detailed Description

The impervious system of the damming body renovation project is the core of the damming lake renovation project reservoir, and consists of a damming body impervious wall, left bank ancient landslide body curtain grouting and right bank bedrock curtain grouting. For the weir plug body with the depth of the impervious wall exceeding 100m and the maximum depth even exceeding 130m, the thickness of the wall body exceeding 1.0m, the content of boulders exceeding 50%, the maximum particle size of the boulders exceeding 15 m, the overhead phenomenon being serious, and the geological conditions of stratum not deposited and cemented being extremely complex, in order to ensure the success of the construction of the groove of the impervious wall, the invention pretreats the stratum before the construction of the groove of the impervious wall, improves the geological conditions of the weir plug body in advance, prevents the slurry leakage and the large boulders from occurring during the construction of the groove of the impervious wall, and effectively avoids the condition that the pre-buried pipe truss and the pre-buried pipe cannot be arranged due to the protruding probe stones on the side wall of the slotted hole in the process of arranging the pre-buried pipe after the groove, improves the survival rate of the pre-buried pipe, and ensures the grouting quality.

In order to enable the embedded pipe to be smoothly arranged downwards, the invention provides a method for arranging the embedded pipe downwards for grouting in the construction of a weir plug body anti-seepage wall, which comprises the following steps:

wherein, pre-buried pipe truss includes: the length extension direction of the embedded pipe is parallel to the axial direction of the slotted hole and is used for fixing a main frame of a plurality of embedded pipes and a plurality of positioning frames fixedly connected with the main frame;

the positioning frames extend along the width direction of the slotted holes and are in line contact with two side walls of the slotted holes respectively, so that the pre-buried pipe truss arranged in the slotted holes along with the pre-buried pipes can not be arranged downwards continuously due to the fact that the pre-buried pipe truss touches a probe stone on the side walls of the slotted holes.

Specifically, the invention takes the axis of the weir plug impervious wall as the reference to carry out the drilling and cleaning construction, and after the slotted hole of the weir plug impervious wall is formed, the embedded pipe can be arranged below the slotted hole. Because the depth of the slotted hole is very deep (100 meters or more), and each embedded pipe is about 6 meters or 12 meters, a plurality of embedded pipes are required to be arranged one by one and connected together until the bottom of the slotted hole, namely, the embedded pipes are arranged into the slotted hole layer by layer with the length of the embedded pipes being one layer high.

When each layer of the pre-buried pipes is arranged below, the lower parts of the pre-buried pipes of the layer are arranged in the slotted holes simultaneously, the upper parts of the pre-buried pipes are exposed out of the slotted holes, then the upper parts or the middle upper parts of the pre-buried pipes in the layer of the pre-buried pipes are positioned simultaneously through a pre-buried pipe truss, and then the pre-buried pipe truss is arranged in the slotted holes together with the pre-buried pipes of the layer.

Among them, the pre-buried pipe truss 300 of the present invention adopts a structure as shown in fig. 7 and 8, which includes: a main frame 31 whose length extending direction is parallel to the axial direction of the slotted hole 100 and used for fixing a plurality of embedded pipes 400, and a plurality of positioning frames 32 fixedly connected with the main frame 31. The positioning frames 32 extend along the width direction of the slotted holes and are in line contact with the two side walls of the slotted holes respectively, so that the pre-buried pipe truss arranged in the slotted holes along with the pre-buried pipes can not be arranged downwards continuously due to the fact that the pre-buried pipe truss touches the probe stones on the side walls of the slotted holes.

The main frame 31 has a truss structure, and as shown in fig. 9 to 11, the truss main body 310 is formed by welding a plurality of vertical beams extending in the depth direction of the slot, a plurality of cross beams extending in the axial direction (i.e., the length direction) of the slot, and a plurality of longitudinal beams extending in the width direction of the slot, and in order to enhance the connection strength, a plurality of oblique beams 312 are further welded to the truss main body 310. In order to facilitate the quick arrangement of the embedded pipes in the main frame 31 for positioning the embedded pipes, a plurality of notches 311 for sleeving a plurality of embedded pipes are formed in one side of the truss main body 310, and the notches 311 are arranged at intervals along the length direction of the truss main body 310.

The plurality of spacers 32 are provided at intervals in the longitudinal direction of the main frame 31, and as shown in fig. 8, only two spacers 32 are shown to be attached to both sides of the main frame 31, but in actual use, the plurality of spacers 32 may be attached to the main frame 31 in accordance with the axial length of the slot (as shown in fig. 19). When the plurality of positioning frames 32 are mounted on the main frame 31, the plurality of positioning frames 32 correspond to the plurality of notches 311 of the main frame 31, respectively, so as to reinforce the strength of the notches 311.

The positioning frame 32 may adopt a first structure as shown in fig. 12, which includes: a first positioning frame fixedly connected to the truss main body 310 of the main frame 31 and extending out of the main frame 31 toward one sidewall of the slot, and having a first connection beam in line contact with the one sidewall of the slot; a second positioning frame 324 fixedly connected to the first positioning frame and extending out of the main frame toward the other side wall of the slot hole, and having a second connecting beam in line contact with the one side wall of the slot hole. During manufacturing, the first positioning frame and the second positioning frame 324 can adopt the same structure and are fixedly connected together in a butt welding mode. Each positioning frame comprises an upper overhanging beam 321 extending along the width direction of the slotted hole, a lower overhanging beam 323 extending along the width direction of the slotted hole, and a connecting beam 322 with two ends respectively connected with the upper overhanging beam and the lower overhanging beam, wherein each beam can be fixedly connected together by a plurality of ribbed steel bars in a welding mode or formed by bending one ribbed steel bar.

Alternatively, the positioning frame 32 may also adopt a second structure including: an upper overhanging beam, one end of which is connected with the upper end of the main frame and extends along the width direction of the slotted hole; one end of the lower suspension beam is connected with the lower end of the main frame and extends along the width direction of the slotted hole; a first connecting beam having both ends connected to one end of the upper cantilever beam and one end of the lower cantilever beam, respectively, and in line contact with one sidewall of the slot; and the two ends of the second connecting beam are respectively connected with the other end of the upper overhanging beam and the other end of the lower overhanging beam and are in line contact with the other side wall of the slotted hole. That is, the second structure of the spacer is no longer formed by butt welding the two spacers.

In order to improve the connection strength between the positioning frame 32 and the main frame 31, the embedded pipe truss may further include a reinforcing beam 33 (as shown in fig. 9) having one end connected to the main frame 31 (e.g., a vertical beam at or near the gap) and the other end connected to the connecting beam of the positioning frame 32. In order to make the pre-buried pipe truss and the two side walls of the slot hole form line contact, each connecting beam of the pre-buried pipe truss is an arc-shaped beam (as shown in fig. 13), that is, as seen from the beam surface of the pre-buried pipe truss, the connecting beam extending along the direction of the slot hole is in an arc shape protruding outwards from top to bottom (i.e. towards the direction of the corresponding side wall of the slot hole to be contacted).

When the positioning frame 32 is coupled to the main frame 31, the positioning frame 32 is eccentrically fixed to the main frame 31, that is, a portion of the positioning frame 32 (e.g., a portion near one of the coupling beams) is welded to the positioning frame 32 (as shown in fig. 13), so that another portion of the positioning frame 32 including the other coupling beam is suspended outside the main frame 31. Of course, the relative positions of the positioning frame 32 and the main frame 31 may be determined according to specific situations. When designing, the extension length of the corresponding positioning frame can be determined according to the width of the slot, and the extension length is generally equivalent to the width of the slot.

The maximum self weight of the pre-buried pipe and the pre-buried pipe truss is about 7.8T, and the weight of the pre-buried pipe truss is close to 16T by adding an 8T steel reinforcement cage, so that an automobile crane is reasonably selected, and the crane is selected for use in consideration of larger hoisting radius. When the pre-buried pipe is suspended, the cross beam 34 processed by I-shaped steel in advance is adopted, and the hook hanging ring 342 is processed at the upper part of the cross beam 34.

Specifically, the cross beam 34 of the present invention may adopt a structure as shown in fig. 15 and 16, including: the beam main body 341; a plurality of lugs 344 provided at intervals on the beam main body 341 along the longitudinal extension direction thereof; the extension direction of the lifting lug 344 is perpendicular to the length extension direction of the beam main body 341, and a plurality of lifting holes for hanging the embedded pipe are formed in the lifting lug 344 at different intervals. In order to facilitate the hanging of the embedded pipes by the crane hook, the lifting lugs 344 are multiple and have different shapes, and the lifting holes formed in the lifting lugs 344 have different shapes, such as a circular lifting hole 343 and a square lifting hole 345 shown in fig. 15, and different embedded pipe hanging points are arranged at the lower part of the cross beam 34, so that the problem of different intervals between the embedded pipes of different groove sections can be solved. During the design, can set up along length direction's scale on the crossbeam to directly sign marks such as pre-buried pipe interval and truss hoisting point, can make the crossbeam play the effect of measuring tape, reduced the numerous and diverse work of measurationing at every turn, and reduced the error between measurement at every turn, guaranteed hoist and mount and divided the precision.

When the embedded pipes are hung below the cross beam, the embedded pipes need to be quickly hung on the hanging holes corresponding to the cross beam through the quick clamping assemblies, and the number of the quick clamping assemblies corresponds to the number of the one-layer embedded pipes which are hung simultaneously. As shown in fig. 17 and 18, the quick clamping assembly includes: the annular buckle 35 is formed by connecting two semi-annular buckles together through bolts; a steel wire rope (not shown in the figure) with two ends respectively detachably connected with the outer sides of the two semi-annular buckles and penetrating through the lifting hole; and a plurality of positioning ribs 404 (shown in fig. 14) which are arranged on the outer wall of the embedded pipe at intervals along the circumferential direction of the embedded pipe and protrude outwards along the radial direction of the embedded pipe, wherein the positioning ribs are 3-4 steel bars which are 3cm in length and 10 in diameter and are uniformly welded on the peripheral part of the top of the embedded pipe and below the edge of the bottom of the sleeve.

Preferably, the semi-annular snap comprises: a first arc buckle 351 with a pin hole at one end; a second arc-shaped buckle 352 with one end connected with the other end of the first buckle 351 through a bolt, and the other end connected with the second buckle of the other semi-annular buckle through a bolt 354; and the hanging lug 353 is arranged on the outer side of the second buckle 352 and is used for fixing the steel wire rope. The inner diameter of the ring formed by the two semi-ring buckles after buckling together is smaller than the inner diameter from the center of the embedded pipe to the outer side wall of the positioning rib 404, so that the embedded pipe can be suspended through the positioning rib 404 when the two semi-ring buckles buckle together. And the size of the closed two semi-annular buckles is matched with the outer diameter of the embedded pipe, and the annular buckle is convenient and free to open and close, improves the downward setting speed and has higher lifting safety. The buckle connection operation is convenient, and the quick hoisting can be realized. The positioning ribs are matched with the annular buckles to play a role in limiting.

Furthermore, when the multilayer embedded pipes are arranged in the slotted holes layer by layer, the embedded pipes corresponding to the positions between the adjacent layers need to be butted, so the equipment also comprises a sleeve for inserting and guiding the two butted embedded pipes in the two adjacent layers of embedded pipes, the bottom end of the sleeve is fixedly connected with the outer wall of the lower embedded pipe in the two butted embedded pipes, and the top end of the sleeve is fixedly or movably connected with the outer wall of the upper embedded pipe in the two butted embedded pipes.

The connecting structure of the sleeve and two adjacent upper and lower embedded pipes in the sleeve insert welding method can be shown in fig. 14, and comprises the following steps: the inner diameter is slightly greater than the sleeve 403 of buried pipe external diameter, insert upper buried pipe 401, the lower buried pipe 402 in sleeve 403 from sleeve 403 upper and lower both ends respectively, and after upper buried pipe 401, lower buried pipe 402 inserted in sleeve 403, pass through welded mode with the outer wall fixed connection of upper buried pipe 401, lower buried pipe 402 respectively with sleeve 403 upper and lower both ends.

The structure that two adjacent upper and lower embedded pipes are connected together by adopting a long sleeve splicing method is basically the same as that in the structure in fig. 14, but the difference is that the length of the sleeve can be longer than or equal to that in the sleeve splicing welding method, and after the upper embedded pipe is inserted into the sleeve, the upper end of the sleeve and the upper embedded pipe are not fixedly welded together.

When the position of the embedded pipe truss is designed, the influence of the positions of a top steel reinforcement cage, the pouring guide pipe 200 and the joint pipe 500 is considered, therefore, the number of the embedded pipes is distributed according to the condition of the slotted holes, the distance between the embedded pipes is consistent with the normal hole position distance of the impervious wall slot, if only 3 embedded pipes are needed, the positioning frame of the embedded pipe truss can be arranged at the positions of two holes (shown in figure 7), the supporting position of the positioning frame not only can ensure that the center of the pouring guide pipe meets the standard requirement of a preset distance (such as 1.0-1.5 m) from the pipe wall of the joint pipe, but also can successfully avoid the position of a small wall with more impervious wall probe stones, and ensure the success rate of arrangement.

If the number of the embedded pipes in the slotted holes is large (5 pipes shown in fig. 19), the spacing between each embedded pipe and the right hole of the slotted hole is kept consistent, in order to not affect the arrangement of the lower part of the pouring guide pipe, the supporting position of the positioning frame is consistent with the hole positions on the two sides of the center, and the success rate of the arrangement of the lower part is ensured, as shown in fig. 19.

The pre-buried pipe truss is before the equipment, and the breach that the accessible was reserved is for pre-buried pipe location, makes things convenient for and assembles before the lower equipment in the future. By adopting the structure that the embedded pipe and the embedded pipe truss are separated firstly and then assembled, a large amount of space can be vacated, and enough storage sites can be ensured.

According to the traditional embedded pipe connection, after two embedded pipes are butted, three to four short steel bars are welded and fixed all around, and by adopting the connection mode, the processing speed is low, the stress is not uniform, the lower installation process is easy to break, the sealing performance is poor, and cement slurry is easy to infiltrate into the pouring process to block the pipeline. The embedded pipe is connected in a sleeve type, so that the processing efficiency and the processing quality are greatly improved. When in design, the embedded pipe and the sleeve can adopt the following parameters: the length of each embedded pipe is 6m, the outer diameter is 114mm, the inner diameter of the sleeve is 117mm, the length of the sleeve is 30cm, one end of each embedded pipe is embedded into the sleeve by 15cm, the other end of each embedded pipe is embedded after welding, the embedded pipes are firmly welded after being straight, and the embedded pipes are connected into a single pipe with the length of 12, so that the embedded pipes can be conveniently arranged in the future, and the overall arrangement speed is increased.

The embedded pipe adopts Q235 steel, and when will embedded pipe and sleeve welding, will embedded pipe and sleeve pipe all around full weld, under this condition, 2mm welding thickness can satisfy the construction strength requirement.

After the embedded pipes and the embedded pipe trusses are processed in batches, the embedded pipes and the embedded pipe trusses are temporarily in a separated state for convenient on-site storage, and the site space is saved. And before the embedded pipe is arranged below the embedded pipe, performing field processing and assembly. During assembly, the steel bars with the same cross section as the pre-buried pipe trusses are welded, and after assembly, the 12m pre-buried pipes and the pre-buried pipe trusses are integrally arranged, so that the arranging speed is increased.

When the embedded pipe is arranged below, the length of the bottom pipe of the embedded pipe can be 12m (namely the embedded pipe arranged at the bottommost part of the slotted hole), two embedded pipe trusses can be adopted, and the length of a single embedded pipe of the two embedded pipe trusses is processed according to the corresponding hole depth. In order to prevent the pipe bottom of the pre-buried pipe from entering concrete mortar during pouring, the front bottom pipe arranged below the pre-buried pipe is sealed in advance. Can adopt the mesh to seal the bottom tube for 2 mm's wire net, prevent that the mortar from scurrying into simultaneously, can make in the slotted hole bentonite thick liquid admission pipe again, pre-buried tub buoyancy was too big when avoiding setting down, and the influence sets up speed. When the bottom pipe is sealed by the steel wire mesh, 2-3 short steel bars are welded at the bottom of the embedded pipe in advance, and after the bottom pipe is wrapped by the steel wire mesh, the steel wire mesh is bound and fixed firmly by iron wires.

After the layer of embedded pipe bottom pipe is arranged below, I-shaped steel penetrates through the embedded pipe trusses welded and fixed with the layer of bottom pipe respectively to be fixed on the guide wall, the bottom embedded pipe is prevented from falling to the bottom of the hole, and the bottom embedded pipe is fixed to be higher than the top of the slotted hole by a certain distance (about 1.3m) so as to facilitate welding operation of the embedded pipe. And loosening the quick clamping assembly for hoisting the bottom pipes, buckling the top of a corresponding one of the upper-layer embedded pipes to be in butt joint with the one layer of bottom pipes by using the annular buckle of the quick clamping assembly, and hoisting by using a crane. After the sleeves at the tops of the bottom pipes in the lifting heel slot holes are butted, the lower setting verticality is adjusted, and the direction of the parallel wall body and the upstream direction and the downstream direction are vertical through general visual observation. After the vertical adjustment, the upper embedded pipe and the lower embedded pipe are welded into a whole through a sleeve, and then the lower embedded pipe is arranged to the position of the orifice with the height of only about 2 m. At the moment, the plurality of gaps of the embedded pipe truss are respectively aligned with the embedded pipes and pushed into the embedded pipes, and then the embedded pipe truss and the embedded pipes are firmly welded to form a whole. Finally, I-shaped steel is fixed on the guide wall, and a certain height is reserved at the pipe orifice to facilitate welding operation. And then, the same method is continuously adopted for butting the embedded pipes, and when the position, which is about 20 meters away from the slotted hole opening and used for placing the steel reinforcement cage, of the position is met, the upper embedded pipe and the lower embedded pipe which are butted in the upper layer of embedded pipes and the lower layer of embedded pipes are butted through the sleeve in a guiding way, and then the upper embedded pipe is not welded with the sleeve, so that the embedded pipes can axially move, but the upper embedded pipe cannot be separated from the sleeve even if the upper embedded pipe floats upwards along with the steel reinforcement cage due to the certain length of the sleeve in the axial direction, and the survival rate of the embedded pipes after the embedded pipes are.

The mode that the embedded pipes and the positioning frame are separately arranged is adopted, the process is arranged below the embedded pipes, each embedded pipe is independent, when the embedded pipes are in butt joint with the lower embedded pipe sleeve, the bottom of each embedded pipe is not restricted, the horizontal direction and the vertical direction can be freely adjusted, and the butt joint speed is accelerated. The overall setting speed is improved. The embedded pipe is butted with the lower sleeve through self weight, so that the embedded pipe can be kept vertical, and the arrangement quality below the embedded pipe can be ensured.

According to the invention, through the improvement of the pre-buried pipe truss, the setting depth and quality under the pre-buried pipe are greatly improved. The positioning frame of the pre-buried pipe truss is arranged in a vertical arc shape, so that the small wall part with more probe stones can be effectively avoided. Meanwhile, the supporting positions of the positioning frame are two single points, compared with a rectangular positioning frame in the prior art, the probability of encountering a probe stone is greatly reduced, and theoretically, the supporting positions of the positioning frame are only 8.3% -16.7% of the rectangular structure. Experiments verify that the setting depth of the embedded pipe can completely meet the design requirement, the setting process is smooth, the phenomenon of blockage in the setting process does not occur on one side, the setting success rate reaches 100%, and the reasonable design of the embedded pipe truss is fully demonstrated.

The internal space of the pre-buried pipe truss is large enough to ensure that the pouring guide pipe is arranged below. And according to the actual condition of arranging the casting guide pipe, the process of arranging the left groove section and the right groove section is smooth, and the condition of arranging the guide pipe under the blockage is not caused. Therefore, the two single-point supporting and positioning frames of the pre-buried pipe truss can meet the positioning requirement.

Through actual engineering verification, after the pre-buried pipe is arranged, the arrangement quality of the pre-buried pipe of each groove section is detected, and through detection of an inclinometer, the maximum vertex angle of the pre-buried pipe is only 0.3 degrees, the maximum deflection rate of the pre-buried pipe is less than 0.2 percent, and the deviation of the hole bottom is not more than 20cm, so that the arrangement quality is guaranteed. And after the pouring is finished, sweeping the holes of the embedded pipes by using a geological drilling machine, wherein the holes are swept to the bottom successfully, no hole forming phenomenon is found, and the survival rate of the embedded pipes reaches 100%.

The method for arranging the lower embedded pipe has the following advantages:

firstly, the embedded pipe truss adopts a two-point supporting mode, and compared with the traditional rectangular frame positioning mode, the material consumption is improved. Taking a second-stage groove with a hole depth of 136m as an example, the embedded pipe truss consumes about 2.1t of steel, and if a traditional mode is adopted, 3.0t of steel is needed. Therefore, compared with the traditional rectangular positioning frame, the steel of the embedded pipe truss after the improved design is saved by about 30%.

Secondly, the invention adopts a mode of separately arranging the pre-buried pipes and the pre-buried pipe trusses and connecting the pre-buried pipes in a sleeve mode, and the statistical average value of the arranging time of the anti-seepage walls with the length of more than 100m is 2.5-3.0 h. Under the condition of the same depth, compared with the traditional embedded pipe and truss integral lower setting and steel bar slit welding connection mode, the statistical time is about 4.0 h-5.0 h, and therefore the lower setting efficiency of the invention is greatly improved, and the construction cost is indirectly saved. The sleeve splicing welding connection mode can guide the lower part of the upper-layer embedded pipe and reduce the possibility of inflection points at the connection position; when the pre-buried pipe is connected with the top reinforcement cage, a long sleeve insertion method is adopted at the joint, so that the pre-buried pipe cannot be interfered or broken when the reinforcement cage floats upwards in a small range, and the survival rate of the pre-buried pipe is greatly improved.

In addition, the contact between the traditional rectangular pre-buried pipe truss and the hole wall is a rectangular side, and the scraping and rubbing of mud sheets on the whole surface of the hole wall are generated when the rectangular pre-buried pipe truss is arranged below the hole wall, so that the reduction of the mud sheets is easy to increase the probability of the collapse accident of the slotted hole, and the scraping and rubbing mud sheets form siltation at the hole bottom to cause adverse effects on secondary hole cleaning. The embedded pipe truss disclosed by the invention adopts a point supporting and positioning mode, and only two straight lines are arranged from the hole opening to the hole bottom at the position where the inner hole wall of the groove hole is contacted when the embedded pipe truss is arranged below the embedded pipe truss, so that the probability of contact between the embedded pipe truss and the hole wall and the probe stone when the embedded pipe truss is arranged below the embedded pipe truss is greatly reduced, the rubbing of mud on the hole wall is reduced, the hole collapse probability is reduced, and the efficiency of secondary hole cleaning is improved.

According to the invention, through the research on the technology for arranging the lower parts of the embedded pipes of the weir plug body impervious wall, the technical problem that the lower parts of the embedded pipes in the large boulder stratum of the weir plug body impervious wall are difficult is solved, the smooth operation of the impervious wall project is favorably ensured, the arrangement quality is obviously improved, the applicability and the economy are improved, and the reference achievement is provided for the construction of the impervious wall of the large boulder stratum in the future.

Further, the method of the present invention further comprises the following pretreatment steps performed before the drilling and cleaning work to form the slotted hole, so as to form a homogenized stratum: pre-blasting treatment is carried out on the axis of the impervious wall of the weir plug body, and boulders with large volume are crushed into small boulders; after the pre-explosion treatment is finished, pre-grouting treatment is carried out on the upstream and the downstream of the axis of the barrier body diaphragm wall, and the leakage passages on the upstream and the downstream of the axis of the barrier body diaphragm wall are blocked.

The pre-explosion treatment on the impervious wall axis of the weir plug comprises the following steps: drilling a row of blast holes at intervals on the axis of the impervious wall of the weir plug body; after the blast hole is drilled, blasting boulders encountered in the blast hole so as to break the boulders into lump stones; the pre-grouting treatment carried out at the upstream and the downstream of the axis of the barrier body diaphragm wall comprises the following steps: after the boulders are crushed into rock blocks, respectively drilling a row of upstream grouting holes and a row of downstream grouting holes with the depth of more than 70 meters at intervals on the upstream and downstream of the axis of the barrier body impervious wall; after the upstream grouting hole and the downstream grouting hole are drilled, grouting treatment is carried out on the grouting holes with the depth of more than 70 meters by adopting a pipe-pulling grouting method or a perforated pipe grouting method, and the leakage channels at the upstream and the downstream of the axial line of the barrier body impervious wall are blocked, so that the trenching construction of the barrier body impervious wall is carried out under the condition of complete and stable stratum.

Specifically, the pretreatment method of the invention comprises the following steps:

s01, reforming the stratum with the content of the boulder exceeding 50 percent into a uniform stratum without the boulder

For the damming body with the boulder content exceeding 50% and the depth of the impervious wall exceeding 100 meters, the invention adopts the blasting method to carry out crushing treatment on a large amount of boulders: first, a blast hole for setting an explosive is drilled, and then, the boulder in the blast hole is crushed by the explosive.

S11 drilling a blast hole

In the invention, a row of blast holes (as shown in figure 1, the blast holes marked by YB in the figure) are drilled on the barrier body diaphragm wall axis at equal intervals, the interval between adjacent blast holes can be 1.2-1.6m, and the preferred embodiment is 1.5 m.

When drilling, according to the geological condition of site construction and the condition allowed by site equipment, drilling to the maximum depth so as to ensure the hole-forming quality of the impervious wall and the safety of the slotted hole as far as possible.

When a blast hole is drilled, the drilling method mainly adopts a pneumatic down-the-hole drill pipe following drilling method and can also adopt a geological drilling machine mud protection wall rotary drilling method, and the drilling principles of the two methods can refer to the prior art method and are not described in detail herein.

When the method of drilling with the pneumatic down-the-hole drill is adopted, the eccentric drill bit is adapted to the sleeve (as shown in a in figure 2), and the sleeve can be a high-quality geological steel pipe with the diameter of 114mm or 146 mm. The air compressor used should be adapted to the working air pressure of the down-the-hole hammer, and generally an air compressor with medium or high air pressure (not shown in the figure) is used.

All the blast holes drilled are vertical holes, and after the drilling machine is aligned with the hole positions, the mast or the vertical shaft of the drilling machine should be adjusted so that the drill rod and the sleeve pipe are kept in the vertical direction. In the drilling process, the perpendicularity of the casing pipe or the drill rod is required to be checked at any time, and problems are found and corrected in time. Particular attention should be paid to controlling the borehole deviation, especially for the upper 20m hole deviation, which requires no more than 1%.

All drilling holes are drilled according to strict operation requirements, so that accidents in the holes are avoided, the hole forming rate of the drilling holes is ensured, and metal objects such as casings and drilling tools cannot be abandoned in the holes.

The process flow when drilling the blast hole is as follows: hole aligning position → aligning drill → open hole → drilling with pipe → compressed air punching → adding drill rod, pipe with pipe → middle inclination testing → next cycle → final hole → hole testing.

When a blast hole is drilled, the hole inclination needs to be strictly controlled, otherwise, the blast cannot achieve the effect outside the impervious wall. In order to prevent the hole inclination of the drilled hole and ensure the verticality of the drilled hole, the invention adopts the following hole inclination ensuring measures:

(1) the foundation is solid and stable, the base platform is firm and regular, the installation of the drilling machine is regular, horizontal and stable, and the direction and the inclination angle of the vertical shaft meet the design requirements.

(2) In the stratum with fault, crack development and rock vein interpenetration, the drilled hole is easy to bend, and the drilling speed is not suitable to be adjusted too fast during drilling.

(3) According to the drilling condition, a field construction technician should timely follow the hole inclination measurement to know the drilling track;

(4) and reasonably determining drilling technical parameters according to the characteristics of the stratum, and selecting a drilling method.

(5) In order to ensure the verticality of the drilled hole, an eccentric hammer is selected for slow drilling in the hole opening stage, and in the following pipe drilling stage, an ST L-1 GW (antimagnetic wireless stored digital gyro inclinometer) high-precision inclinometer can be used for hole inclination measurement control, and the inclination measurement is carried out by a professional.

In addition, the stratum change should be noticed at any time in the drilling process, when the cobble is drilled, the drilling speed should be slowed down, the hole wall should be drilled and trimmed repeatedly, the cobble is ensured to pass through smoothly along with the pipe, and the pipe is prevented from being blocked, so that the casing pipe is prevented from being broken. Meanwhile, the screw thread of the heel tube is subjected to enhanced inspection, the damaged screw thread needs to be replaced in time and is reprocessed, so that the screw thread in the hole is prevented from being broken and accidents in the hole are avoided.

Because the drilling equipment belongs to large-scale equipment and needs to be enhanced to maintain in use, the invention requires that the construction of a construction unit is suspended every 30 days, the equipment is forcibly checked and maintained, so that the equipment is always kept in a good state, and maintenance records of the sound large-scale equipment are established.

It should be noted that, because the requirement of the blast hole on hole inclination is extremely high, if the hole is inclined out of the range of the impervious wall, pre-blasting becomes meaningless, and the current down-the-hole drill construction can basically ensure that the hole is not inclined out of the impervious wall when the hole is constructed to 70m, but hardly ensures that the hole is inclined out of the impervious wall when the hole is more than 70m, so the blast hole construction can be carried out to about 70m deepest, and the boulder below 70m can be subjected to in-hole blasting treatment in the subsequent impervious wall construction process.

S12, crushing the boulder in the blast hole

When a high-frequency impactor is configured with a full-hydraulic drill to drill a blast hole along with a pipe, one-time drilling is performed to the bottom, in addition, in the drilling process, slag discharge and drilling conditions are closely observed, the number of boulders in the blast hole, the positions of the boulders and the sizes of the boulders are recorded in detail according to the drilling difficulty and the air return condition in the hole in the down-the-hole drilling process, and the positions of the boulders in the whole hole are sorted and labeled after the drilling is completed. And then, calculating the depth of the center of each boulder in the blast hole by taking the whole blast hole as a reference, and marking the size of the boulder corresponding to the depth. And finally, crushing each boulder in the blast hole.

After the blast hole is drilled and the position and size information of the corresponding boulder is determined, and before formal blasting construction of the boulder, the invention also needs to carry out a field simulation full-hole blasting test to determine the explosive quantity control parameter during blasting.

In the test, the diameter of the test boulder is properly determined according to the boulder with the approximately same diameter and the largest content in the stratum, and the test times can be determined according to the actual situation.

The invention passes through three times of field simulation full-hole blasting tests, and the test data are respectively as follows:

the first test: the drilling depth is 3m, the diameter of the maximum boulder is 1.0m, the total loading is 5.4Kg, and the average loading is 1.8 Kg/m;

and (3) second test: the drilling depth is 5m, the diameter of the maximum boulder is 2.0m, the total loading is 12.5Kg, and the average loading is 2.5 Kg/m;

for the third test: the drilling depth is 10m, the diameter of the maximum boulder is 3.0m, the total loading is 33Kg, and the average loading is 3.3 Kg/m.

After each field explosion is finished, excavation is immediately carried out, the explosion effect is visually checked, the boulder is broken into blocky stones and partial powder after the first two times of explosion, but the blocky stones still exist, and the boulder is broken into blocky stones with uniform sizes after the third time of explosion (the diameter of each blocky stone is between 5 and 50cm, the diameter is uniform, namely the number of the blocky stones with the same diameter is large), so that the loading capacity of the method can be controlled to be between 2 and 3kg/m according to specific geological conditions and field simulation test results, and is preferably 3 kg/m.

After the loading amount required by the boulder with a large crushing content is determined by the test method, each explosive is bound by using a transparent adhesive tape (only one end is bound and fixed) according to every four sections (1.2 kg in total), then, the explosive is bound by using a binding band with poor flexibility such as a nylon rope, the explosive is bound by using the bottom of the rope as the center of the first boulder at the bottom of the hole, and the binding position of the corresponding explosive is diffused to the two ends of the center according to the size of the first boulder. And after the binding position is determined, placing a detonator in the bound explosive, winding and fixing the detonator line on the nylon rope, and secondarily fixing the explosive by using a transparent adhesive tape. And taking out the center position of the upper boulder in the same blast hole according to the amount of the center position of the first boulder to be bound, and binding corresponding explosives according to the position, the size information and the corresponding explosive quantity of each boulder obtained originally by analogy until the orifice position of the blast hole is measured, and marking.

After the binding of all explosives in the whole blast hole is finished, arranging the explosives below the PVC pipe which is arranged in advance through the suspension wire, binding and fixing the suspension wire at the marked orifice position, after the binding is finished, leading out the detonating cord of the blast hole to the detonator, and performing blasting construction after the safety warning is finished.

It should be noted that, for the individual boulders with the maximum particle size exceeding 10m, the loading amount needs to be increased appropriately, and in addition, the boulders can be crushed by adopting a separate loading blasting method during the process of forming the impervious wall groove. Of course, if the boulder with the diameter less than 1 meter is encountered, the loading amount can be also reduced properly.

The processing of the boulders in all blast holes can be carried out according to the method, and the detailed description is omitted.

Before the construction of the impervious wall, a row of blast holes are drilled along the axis of the slot hole of the impervious wall, all boulders in the blast holes are blasted, and the boulders are crushed into small boulders, so that the original stratum with high boulder content is improved into a stratum with low boulder content, even without boulders and only with uniform small boulders, the situations of hole inclination exceeding standard and low grooving efficiency when the large boulders cause the subsequent grooving and hole forming of the impervious wall are effectively prevented, and the construction progress and quality of the impervious wall are ensured.

S02, reforming the loose and overhead stratum into a stable and complete stratum

After the boulder is crushed by the blasting method, the stratum has no more boulder, but the original stratum is looser, and the stratum after blasting is looser, so that the stratum is leveled by drilling grouting holes and grouting the unconsolidated stratum through the grouting holes as shown in fig. 3 in order to improve the integrity and stability of the unconsolidated stratum.

S21 drilling grouting holes

After the boulders are crushed into uniform stones, a row of upstream grouting holes (holes marked as YGS in figure 1) and a row of downstream grouting holes (holes marked as YGX in figure 1) with the depth of more than 70 meters are drilled at intervals respectively at the upstream and the downstream of the axis of the barrier body impervious wall, namely at the two sides of the axis of the barrier body impervious wall. The distance between the grouting holes and the axis of the impervious wall is 0.9m, the row spacing between the upstream grouting hole and the downstream grouting hole is 1.8m, and the hole spacing is 2.0 m. Wherein, the row pitch refers to the distance along the water flow direction, and the hole pitch refers to the distance perpendicular to the water flow direction.

When drilling, according to the geological condition of site construction and the condition allowed by site equipment, drilling to the maximum depth (at least more than 70 meters) so as to ensure the hole-forming quality of the impervious wall and the safety of the slotted hole as far as possible. The drilling method of the grouting hole can adopt the method of the pneumatic down-the-hole drill pipe following drilling of the blast hole, and can also adopt the method of the geological drilling machine mud retaining wall rotary drilling, and the details are not repeated.

It should be noted that, during the process of drilling the grouting holes, the upstream grouting holes and the downstream grouting holes should be arranged in a triangle, that is, as shown in fig. 1, from the hole site layout diagram of the blast holes and the grouting holes, one downstream grouting hole is located between two upstream grouting holes, and one upstream grouting hole is located between two downstream grouting holes. The upstream grouting holes and the downstream grouting holes are arranged in a triangular shape, so that grouting liquid can fully flow into loose formations on two sides of the impervious wall during grouting.

S22, grouting into the grouting hole

And after the upstream grouting hole and the downstream grouting hole are drilled, grouting the upstream grouting hole and the downstream grouting hole by adopting a pipe drawing grouting method.

The process of grouting each grouting hole by using the pipe drawing grouting method can be as shown in fig. 4(a-e), and comprises the following steps;

when the grouting hole is drilled to a preset depth (shown as a in figure 4), taking out the eccentric drill in the casing (shown as b in figure 4);

after the eccentric drill is taken out, the casing is lifted to form a grout section having a length corresponding to the lifting depth of the casing (as shown by c in fig. 4, the height is lifted by 1 meter to be the length of the grout section);

pouring grouting liquid at least comprising cement clay slurry into the grouting section by adopting a self-flow pouring method (as shown by d in figure 4);

after the bottom of the grouting section reaches the end standard, the casing is lifted (as shown by e in fig. 4, the height is lifted by 1 meter to be used as the length of the grouting section), and grouting is continued in the above manner until the whole grouting hole is completely grouted.

Or after the upstream grouting hole and the downstream grouting hole are drilled, grouting treatment can be performed on the upstream grouting hole and the downstream grouting hole by adopting a perforated pipe grouting method, and the method comprises the following steps:

when the grouting hole is drilled to a preset depth, taking out the eccentric drill in the casing;

after the eccentric drill is taken out, a perforated pipe with a grout outlet is arranged below the sleeve;

after the flower tube is completely arranged below the flower tube, the sleeve is taken out, and grouting liquid containing cement clay slurry is poured into the flower tube by adopting a hydraulic plug;

when grouting liquid is poured, the grouting liquid flows to the grouting holes and the adjacent unconsolidated strata through the grout outlet of the perforated pipe, and the grouting holes are grouted section by section from bottom to top.

When the perforated pipe is adopted for grouting, the structure diagram of the perforated pipe is shown in fig. 5, a PVC perforated pipe is adopted, the diameter of the perforated pipe is phi 89mm, each circle of grout outlet holes are drilled at every 0.5m on the outer wall of the perforated pipe, each circle of grout outlet holes comprises 3 grout outlet holes (namely, the grout outlet holes are spaced at 120 degrees along the circumferential direction of the perforated pipe), the aperture of each grout outlet hole can be 1.5cm, and the grout outlet holes are sealed by using adhesive tapes. The length of every section floral tube can be 3.0 ~ 6.0m, connects between the adjacent floral tube, connects and to adopt prior art connected mode, adjusts according to the construction conditions, nevertheless will ensure to set up the floral tube when can not loosen and take off. After the floral tube is completely arranged below the floral tube, the sleeve is pulled out by using a tube drawing machine, and the PVC floral tube is left in the drilled grouting hole so as to be grouted section by section from bottom to top by adopting a hydraulic plug.

Regardless of the grouting method, a method of simultaneously grouting through a plurality of grouting holes or a method of grouting through a single grouting hole may be used in grouting.

The grouting liquid at least comprising cement clay slurry is cement clay slurry, the water-solid ratio is 0.7:1 and 0.4:1, and 5% or 10% of water glass is added into the grouting liquid with the water-solid ratio of 0.4:1 for grouting if necessary, so that the consistency of the grouting liquid is increased, the setting time of the grouting liquid is accelerated, the setting time of the grouting liquid is controlled, the diffusion range of the grouting liquid is controlled, the grouting is controllable, grouting materials can be saved, and a leakage channel can be effectively blocked.

The slurry preparation adopts a ZJ-400 type stirrer, and the concrete pulping is carried out according to the following procedures: pulping: adding water, adding cement, stirring, adding slurry, and stirring for 2 min; the cement clay slurry can be used after being expanded for 4-6 hours under the condition, and can be directly used under the condition; after the cement clay slurry is produced, it is passed through a screen to remove large particles, and then fed into a slurry tank, in which a perforated pipe is placed, and the slurry in the tank is pumped or stirred by high-pressure air so as to make it be in uniform state.

During grouting, the water-solid ratio of cement clay slurry in grouting liquid is adjusted at any time according to the grouting amount of the grouting liquid in a grouting hole and the grouting coefficient Q/P (Q is the grouting flow and P is the grouting pressure):

when the grouting amount of grouting liquid in the grouting hole is less than 200kg/m, the grouting liquid is cement clay slurry with the water-solid ratio of 0.7:1, and the grouting liquid comprises the following components: cement, clay and water, wherein the weight ratio of the cement to the clay to the water is 1: 1: 1.4;

when cement clay slurry with a water-solid ratio of 0.7:1 is adopted for grouting and the groutability coefficient Q/P is basically unchanged, the pouring amount of grouting liquid is increased to ensure that the pouring amount of the grouting liquid is more than or equal to 200kg/m and less than 300kg/m, and the grouting liquid adopts the cement clay slurry with the water-solid ratio of 0.4:1, and the method comprises the following steps: cement, clay and water, wherein the weight ratio of the cement to the clay to the water is 1: 1: 0.8;

when cement clay slurry with a water-solid ratio of 0.4:1 is adopted for grouting and the groutability coefficient Q/P is basically unchanged, the pouring amount of grouting liquid is increased to enable the pouring amount of the grouting liquid to be larger than or equal to 300kg/m and smaller than 1000kg/m, and at the moment, 5% of water glass is doped in the cement clay slurry with the water-solid ratio of 0.4:1, wherein the cement clay slurry comprises: cement, clay and water, wherein the weight ratio of the cement to the clay to the water is 1: 1: 0.8, and the weight ratio of the cement clay slurry to the water glass is 1: 0.05;

when cement clay slurry with a water-solid ratio of 0.4:1 and grouting liquid doped with 5% of water glass are adopted for grouting and the groutability coefficient Q/P is basically unchanged, the grouting amount of the grouting liquid is increased to enable the grouting liquid to be poured in an amount which is more than or equal to 1000kg/m and less than 2000kg/m, and at the moment, the grouting liquid is prepared by doping 10% of water glass into the cement clay slurry with the water-solid ratio of 0.4:1, wherein the cement clay slurry comprises: cement, clay and water, wherein the weight ratio of the cement to the clay to the water is 1: 1: 0.8, and the weight ratio of the cement clay slurry to the water glass is 1: 0.1;

when the grouting amount of grouting liquid in the grouting hole is more than or equal to 2000kg/m, the grouting of the section can be finished, or when the grouting pressure reaches more than 0.5Mpa and the grouting injection rate is still low (less than 10L/min), the grouting of the section can be finished.

In addition, when grout is poured, the grouting pressure is adjusted at any time according to the grout consumption in the grouting hole, generally, the grouting pressure is 0.2-0.5 Mpa, when the grout consumption is large, the grouting pressure is low, and when the grout consumption is small, the grouting pressure is high.

It should be noted that, for a stratum which is found to have more solitary rock content, larger particle size and more serious stratum overhead condition through geological data and exploration hole analysis, grouting must be performed according to the above finishing standard, and for each grouting hole close to the bedrock, the adjacent hole pitch in the upstream row of grouting holes is encrypted, for example, the original hole pitch is encrypted from 2m to 1m to 1.5m, and the unit consumption of grouting is adjusted, generally, the unit consumption is 1500-2000 Kg/m.

In addition, in the actual construction process, grouting and finishing standards and the like can be adjusted according to the actual conditions of the stratum:

for example, for a grouting hole close to an ancient landslide body, when the grouting amount of grout in the hole is less than 200kg/m, the grouting can be performed by adopting cement clay grout with the water-solid ratio of 0.7:1, when the grouting amount is more than or equal to 200kg/m, the grouting can be performed by adopting more concentrated grout, such as cement clay grout with the water-solid ratio of 0.4:1, and when the grouting amount is more than or equal to 300kg/m, the grouting of the section can be finished.

The method has the advantages that by grouting the stratum before grooving construction of the barrier dam body, the leakage passages at the upstream and the downstream of the axis of the barrier dam body barrier dam wall can be plugged, so that grooving construction of the barrier dam body barrier dam wall is carried out under the condition that the stratum is complete and stable.

Of course, during specific construction, the grouting process and the blasting process can be alternatively constructed according to the influence of a working face.

Once severe slurry leakage and hole collapse occur in the construction of the barrier plug impervious wall, the groove section is possibly backfilled, so that the construction period is delayed, and the economic loss is huge, but by adopting the method disclosed by the invention, the stratum before the grooving construction is performed is subjected to blasting treatment (namely pre-blasting), large boulders in the stratum can be completely blasted to form small boulders, the stratum is subjected to grouting treatment (namely pre-grouting) in advance, a leakage channel can be plugged in advance, the stratum cementation is also well improved, the stability of damaged and loose accumulation bodies around the groove holes is greatly improved, the slurry leakage and hole collapse in the subsequent grooving construction of the impervious wall are greatly reduced, the construction period is shortened, the progress and the quality of the grooving construction of the impervious wall are ensured exactly, the direct economic cost of handling accidents is saved, and the economic benefit is obvious.

Although the present invention has been described in detail, the present invention is not limited thereto, and those skilled in the art can modify the principle of the present invention, and thus, various modifications made in accordance with the principle of the present invention should be understood to fall within the scope of the present invention.

Claims

1. A method for arranging a grouting embedded pipe below a weir plug body diaphragm wall in construction comprises the following steps:

use the axis of damming body cut-off wall as the benchmark, form the slotted hole through drilling and clear hole construction, then hang down the buried pipe in order to establish multilayer buried pipe successive layer in the slotted hole through the crossbeam layer by layer, its characterized in that:

when each layer of the pre-buried pipes is arranged below, the lower parts of the layers of the pre-buried pipes are arranged in the slotted holes at the same time, then a plurality of gaps of a pre-buried pipe truss are respectively aligned with the pre-buried pipes, then the pre-buried pipe truss is pushed to the pre-buried pipes and is welded with the pre-buried pipes, the layers of the pre-buried pipes are positioned at the same time, and the pre-buried pipe truss is arranged in the slotted holes along with the layers of the pre-buried pipes;

wherein the pre-buried pipe truss comprises: the length extension direction of the main frame is parallel to the axial direction of the slotted hole and is provided with a plurality of gaps for fixing a plurality of embedded pipes, and a plurality of positioning frames which are fixedly arranged at the plurality of gaps of the main frame and are arranged at intervals along the length direction of the main frame;

wherein, the locating rack includes: the first positioning frame is fixedly connected with the main frame and extends out of the main frame along the width direction of the slotted hole towards one side wall of the slotted hole; the second positioning frame is fixedly connected with the main frame and extends out of the main frame along the width direction of the slotted hole towards the other side wall direction of the slotted hole;

wherein, first locating rack and second locating rack all include: an upper cantilever beam extending in the width direction of the slot; a lower cantilever beam extending in the width direction of the slot; the two ends of the connecting beam are respectively connected with the upper suspension beam and the lower suspension beam; wherein, each connecting beam is an arc beam which protrudes towards the corresponding side wall of the slotted hole along the depth extension direction of the slotted hole so as to form line contact with the side wall of the corresponding slotted hole.

2. The method of claim 1, wherein the plurality of notches are open in the frame and are spaced apart along a length of the frame.

3. The method according to any one of claims 1-2, wherein when the multilayer embedded pipe is arranged in the slot hole layer by layer, the method comprises the following steps:

4. The method of claim 3, wherein the two embedded pipes which are adjacent to each other at the upper part and the lower part are connected together by a sleeve plug welding method, comprising the following steps:

5. The method of claim 4, wherein the step of connecting the two embedded pipes adjacent to each other comprises:

6. The method of claim 1, wherein the beam comprises:

a beam main body;

a plurality of lifting lugs are arranged on the beam main body at intervals along the length extension direction of the beam main body;

the extending direction of the lifting lug is perpendicular to the length extending direction of the beam main body, and a plurality of lifting holes with different intervals are formed in the lifting lug.

7. The method of claim 1, further comprising the step of pretreating the formation of the weir to form a homogeneous formation prior to forming the slot of the weir dam retention wall.