Synchronous grouting method for double-shield TBM (tunnel boring machine) and shield tail structure thereof
By adopting the synchronous grouting method and step-shaped shield tail structure in the double shield TBM, the problem of no support at the bottom when the shield tail is released during the construction of large-diameter TBM is solved, and the early strength formation and construction efficiency are achieved.
Patent Information
- Application Number
- CN202410818702.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2024-12-10
AI Technical Summary
In the construction of large-diameter double shield TBM, the efficiency of bean gravel blowing and grouting equipment is difficult to meet the excavation efficiency, resulting in no effective support at the bottom when the shield tail is released, and the grouting does not form strength, which is easy to damage the pipe sheet.
The synchronous grouting method is adopted to first fill the fast-coagulation slurry at the lower part of the annular cavity. After solidification, bean gravel is blown on the upper part and cement slurry is poured into a grouting body, combining with the step-shaped shield tail structure to grout in advance and provide support.
The slurry is filled in time before the shield tail is removed, providing early strength support, avoiding the situation of no support at the bottom, and improving the stability and construction efficiency of the pipe piece.
Smart Images
Figure CN119102639A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of building construction, and in particular to a synchronous grouting method for a double-shield TBM and a shield tail structure thereof. Background Art
[0002] The construction method of hard rock tunnel boring machine (TBM) has the advantages of high construction efficiency, good tunnel forming, and little impact on the surrounding environment. It is suitable for the construction of deep and long tunnels and has been successfully applied in tunnel engineering construction in the fields of energy, transportation, water conservancy and national defense in various countries around the world. Among them, the double shield TBM can use its two excavation modes to adapt to different types of geological conditions. In complex geological environments, it has higher applicability and flexibility than open and single shield TBMs. When using prefabricated segment lining, the traditional construction method uses a two-stage filling method of pea gravel + grouting behind the segment to ensure good early support and overall water-stopping effect.
[0003] However, for large-diameter TBMs, the amount of pea gravel blowing and grouting is large, and the efficiency of the subsequent pea gravel blowing and grouting equipment is difficult to meet the excavation efficiency of the TBM, resulting in the pea gravel filling and grouting not being synchronized to the shield tail, and the bottom of the 1-3 ring segments out of the shield tail is without any effective support; for the 3-7 rings of the shield tail, the bottom has been filled with pea gravel but not grouting, and the single pea gravel is a loose structure with insufficient support stiffness; after the 7th ring of the shield tail, the pea gravel blowing and grouting are completed, but the slurry has not yet formed strength. However, the concentrated load formed by the subsequent trailer parked on the 7th ring segment is easy to damage the segment. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a synchronous grouting method and a shield tail structure for a double-shield TBM, so as to timely grout the lower area of the annular cavity after the shield tail is separated from the segment, thereby providing support for the segment in time.
[0005] To achieve the above object, the technical solution adopted by the present invention is a synchronous grouting method for a double shield TBM, wherein an annular cavity is formed between the annular segment and the surrounding rock, and the grouting method comprises the following steps:
[0006] Step 1: As the double shield TBM advances, quick-setting slurry is poured into the lower area of the annular cavity from the grouting holes on the bottom segment;
[0007] Step 2: After the quick-setting slurry solidifies, pea gravel is blown into the upper area of the annular cavity from the grouting hole on the top segment;
[0008] Step 3: After the pea gravel is filled, cement slurry is poured into the gap between the upper area of the annular cavity and the pea gravel from the grouting hole on the top pipe segment, and the pea gravel and the cement slurry are mixed to form a grouting body.
[0009] A further improvement of the synchronous grouting method for double-shield TBM of the present invention is that the lower area is a fan-shaped range of 90°-150° at the bottom of the annular cavity, and the upper area is other areas in the annular cavity except the lower area.
[0010] A further improvement of the synchronous grouting method for double-shield TBM of the present invention is that the quick-setting slurry is cement mortar mixed with water glass.
[0011] A shield tail structure for implementing the synchronous grouting method for a double-shield TBM as described in claim 1, comprising a stepped shield tail, wherein the stepped shield tail includes a bottom shield tail adapted to the lower area of the annular cavity, and a top shield tail adapted to the upper area of the annular cavity, wherein the bottom shield tail is shortened compared to the top shield tail so as to inject the quick-setting slurry into the lower area of the annular cavity in advance.
[0012] A further improvement of the shield tail structure of the present invention is that the tail end of the top shield tail is connected to a shield tail slag blocking plate for resisting the grouting body, and the tail end of the bottom shield tail is connected to a shield tail sealing brush for blocking the quick-setting slurry.
[0013] A further improvement of the shield tail structure of the present invention is that it also includes a baffle for preventing quick-setting slurry from invading the shield tail, wherein the baffle is connected to the inner periphery of the bottom shield tail and extends radially and is flush with the inner side of the bottom pipe segment.
[0014] Compared with the prior art, the advantages of the present invention are:
[0015] 1. The entire annular cavity is adjusted from the traditional grouting method of pea gravel and cement slurry to the grouting method of pea gravel and cement slurry for the upper grouting, and quick-setting slurry is used for the lower grouting, so that the slurry is filled in time before the segment is removed from the shield tail and the early strength is guaranteed, avoiding the situation where the bottom of the segment has no support at all.
[0016] 2. By setting a stepped shield tail, the bottom shield tail can be quickly removed from the pipe segment, so that the lower area of the annular cavity can be filled earlier and strength can be formed earlier to facilitate pipe segment support. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] Figure 1It is a side view of the grouting state of the synchronous grouting method used for double-shield TBM of the present invention.
[0019] Figure 2 It is a cross-sectional view of the synchronous grouting method for double-shield TBM of the present invention when the grouting is completed.
[0020] Figure 3 It is a schematic diagram of the top shield tail structure of the synchronous grouting method for double-shield TBM of the present invention.
[0021] Figure 4 It is a schematic diagram of the bottom shield tail structure of the synchronous grouting method for double-shield TBM of the present invention.
[0022] In the figure: 1. Top shield tail; 2. Bottom shield tail; 3. Grouting body; 4. Pea gravel; 5. Quick-setting slurry; 6. Segment; 7. Baffle; 8. Surrounding rock; 9. Shield tail slag baffle; 10. Shield tail sealing brush. DETAILED DESCRIPTION
[0023] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0024] The synchronous grouting method for double-shield TBM and the shield tail structure thereof of the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0025] See also Figure 1 to Figure 4 As shown, a synchronous grouting method for a double shield TBM is used, wherein an annular cavity is formed between the annular segment and the surrounding rock 8, and the grouting method comprises the following steps:
[0026] Step 1: As the double shield TBM advances, quick-setting slurry 5 is poured into the lower area of the annular cavity from the grouting holes on the bottom segment;
[0027] Step 2: After the quick-setting slurry 5 solidifies, pea gravel 4 is blown into the upper area of the annular cavity from the grouting hole on the top segment;
[0028] Step 3: After the pea gravel 4 is filled, cement slurry is poured into the gap between the upper area of the annular cavity and the pea gravel 4 from the grouting hole on the top pipe segment, and the pea gravel 4 is mixed with the cement slurry to form a grouting body 3.
[0029] Specifically, the early consolidation strength of the grouting body 3 should be no less than 0.2 MPa on the day of final setting, and the strength should be no less than 2.5 MPa at 28 days.
[0030] Specifically, the injection volume of the grouting body 3 should be 1.3 to 1.8 times the theoretical volume of the upper area.
[0031] Preferably, the lower area is a sector-shaped range of 90°-150° at the bottom of the annular cavity, and the upper area is other areas in the annular cavity except the lower area.
[0032] By designing the lower area to be smaller than the upper area, the amount of the quick-setting slurry 5 is reduced without affecting the supporting effect of the quick-setting slurry 5, thereby saving costs.
[0033] Preferably, the quick-setting slurry 5 is cement mortar mixed with water glass.
[0034] By adding water glass into the cement mortar, the consolidation period is shortened.
[0035] A shield tail structure for implementing the synchronous grouting method for a double-shield TBM as claimed in claim 1, comprising a stepped shield tail, the stepped shield tail comprising a bottom shield tail 2 adapted to the lower area of the annular cavity, and a top shield tail 1 adapted to the upper area of the annular cavity, the bottom shield tail 2 being shortened compared to the top shield tail 1 so as to inject the quick-setting slurry 5 into the lower area of the annular cavity in advance.
[0036] Specifically, the shortened length of the bottom shield tail 2 compared with the top shield tail 1 is determined according to the ring width of each ring of the tube segment 6 , and is an integral multiple of the ring width of each ring of the tube segment 6 .
[0037] By setting a stepped shield tail, the bottom shield tail 2 is shortened compared to the top shield tail 1, which makes it easier for the bottom shield tail 2 to escape from the bottom segment first, so that timely grouting of the bottom of the bottom segment before it escapes from the bottom shield tail 2 is achieved, and the lower grouting is completed when the bottom segment escapes from the shield tail, so that early strength is formed as soon as possible, avoiding the situation where the support at the bottom of the segment 6 is unstable or there is no support.
[0038] Preferably, the tail end of the top shield tail 1 is connected with a shield tail slag blocking plate 9 for resisting the grouting body 3 , and the tail end of the bottom shield tail 2 is connected with a shield tail sealing brush 10 for blocking the quick-setting slurry 5 .
[0039] Specifically, the shield tail slag baffle plate 9 includes two first blades arranged in a V shape, the first ends of the two first blades are respectively connected to the inner and outer sides of the top shield tail 1, and the second ends extend outward and respectively press against the surrounding rock 8 and the outer side of the top pipe segment; the shield tail sealing brush 10 includes a plurality of pairs of second blades arranged at intervals along the length direction of the bottom shield tail 2, each pair of second blades is arranged in a V shape, and the first ends of each pair of second blades are respectively connected to the inner and outer sides of the bottom shield tail 2, and the second ends extend outward and respectively press against the surrounding rock 8 and the outer side of the bottom pipe segment.
[0040] Preferably, a baffle 7 is further included for preventing the quick-setting slurry 5 from invading the shield tail. The baffle 7 is connected to the inner periphery of the bottom shield tail 2 and extends radially and is flush with the inner side of the bottom segment.
[0041] Since the quick-setting slurry 5 has strong fluidity, when the shield tail sealing brush 10 cannot block the quick-setting slurry 5, the baffle 7 serves as a second line of defense to prevent the quick-setting slurry 5 from invading the shield tail.
[0042] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.
[0043] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A synchronous grouting method for a double shield TBM, wherein an annular cavity is formed between the annular segment and the surrounding rock. It is characterized in that The grouting method comprises the steps of: Step 1: As the double shield TBM advances, quick-setting slurry is poured into the lower area of the annular cavity from the grouting holes on the bottom segment; Step 2: After the quick-setting slurry solidifies, pea gravel is blown into the upper area of the annular cavity from the grouting hole on the top segment; Step 3: After the pea gravel is filled, cement slurry is poured into the gap between the upper area of the annular cavity and the pea gravel from the grouting hole on the top pipe segment, and the pea gravel and the cement slurry are mixed to form a grouting body.
2. The synchronous grouting method for a double shield TBM according to claim 1, It is characterized in that The lower area is a sector-shaped range of 90°-150° at the bottom of the annular cavity, and the upper area is other areas in the annular cavity except the lower area.
3. The synchronous grouting method for a double shield TBM according to claim 1, It is characterized in that The quick-setting slurry is cement mortar mixed with water glass.
4. A shield tail structure for implementing the synchronous grouting method for a double shield TBM as claimed in claim 1, It is characterized in that The invention comprises a stepped shield tail, wherein the stepped shield tail comprises a bottom shield tail adapted to the lower area of the annular cavity, and a top shield tail adapted to the upper area of the annular cavity; the bottom shield tail is shorter than the top shield tail so as to inject the quick-setting slurry into the lower area of the annular cavity in advance.
5. The shield tail structure as claimed in claim 4, It is characterized in that The tail end of the top shield tail is connected with a shield tail slag blocking plate for resisting the grouting body, and the tail end of the bottom shield tail is connected with a shield tail sealing brush for blocking the quick-setting slurry.
6. The shield tail structure as claimed in claim 4, It is characterized in that It also includes a baffle for preventing quick-setting slurry from invading the shield tail. The baffle is connected to the inner periphery of the bottom shield tail and extends radially and is flush with the inner side of the bottom pipe segment.