Shield segment backfill grouting detection test device and preparation method thereof

Abstract

The invention discloses a shield segment post-wall grouting detection test device and a preparation method. The shield segment post-wall grouting detection test device comprises an inner detection cavity, a shield segment layer is arranged on the outer side of the inner detection cavity in a surrounding mode, a mortar layer is arranged on the outer side of the shield segment layer, and an outer enclosure unit is arranged outside the mortar layer. By building the shield segment model, various types of defect parts can be conveniently arranged on the mortar layer, characterization forms and characterization characteristics of various detection methods on the defect parts are systematically explored, information such as the scale, the position, the shape and the type of the actual defect parts is reversely deduced in combination with the actual detection result, and the detection accuracy is improved. And a basis is provided for accurately determining tunnel defect parts.

Description

Technical Field

[0001] The present application relates to a shield segment wall back grouting detection test device and a preparation method. Background Art

[0002] Since the 21st century, science and technology have developed rapidly, and shield construction technology has been continuously improved and enhanced. The shield method has the advantages of economy, safety, and efficiency, and is widely used in tunnel construction projects such as railways, highways, municipal administration, water supply, gas supply, flood control, and hydropower. The shield method has the advantages of high mechanical automation, little impact from climate factors, reduced disturbance to the ground, and less interference with urban traffic. It is more economical and effective to use the shield method in subway excavation and other aspects.

[0003] When tunneling with shield method, an annular gap will be formed between the excavation surface and the segment. Slurry needs to be injected into the gap to maintain the stability of the stratum. This process is called shield segment wall grouting. Ensuring the quality of segment wall grouting is an extremely important part of ensuring the safety of shield tunnels and the surrounding environment. The detection of shield segment wall grouting quality is particularly important. However, my country's "Shield Method Tunnel Construction and Acceptance Code" (GB 50446-2017) does not specify a specific detection method for shield segment grouting quality detection. Therefore, it is very necessary to conduct a systematic study on the non-destructive detection method of shield segment grouting quality, summarize and analyze the characteristics and adaptability of different methods, so as to better guide the detection of shield segment wall grouting defects. At present, electromagnetic wave method, impact echo method and ultrasonic method are mainly used for non-destructive detection of shield segment wall grouting quality at home and abroad.

[0004] The electromagnetic wave method is currently a widely used method, but when electromagnetic waves propagate in materials with high dielectric constants, the transmission ability is poor, and most of the electromagnetic waves are reflected back, so it is impossible to detect the covering under the high dielectric constant material. Therefore, in pipe segments with more steel bars, this method will produce more invalid signals. Therefore, it is necessary to establish a pipe segment wall back grouting defect model with variable scenarios, and systematically study the advantages and disadvantages of the electromagnetic wave method for detecting the quality of pipe segment wall back grouting under the influence of steel mesh.

[0005] The industry standard "Technical Specifications for Detecting Concrete Defects by Impact Echo Method" briefly explains "Detection of Grouting Defects Behind Tunnel Lining and Judgment of Results", but does not provide specific operational suggestions for detecting the quality of grouting behind the segment wall by the impact echo method. Therefore, it is necessary to use the self-built shield segment wall grouting detection test platform to carry out research and verification in this regard and provide operational standards.

[0006] Ultrasonic waves have a strong directivity, which is proportional to the ultrasonic frequency. They carry a lot of information, and their characteristics such as acoustic time, amplitude, frequency, and phase can all provide a basis for analyzing the test results. At present, there are few reports on the research of ultrasonic testing technology for the quality detection of post-grouting behind shield segments. Therefore, incorporating ultrasonic testing technology into the systematic research system for the quality detection of post-grouting behind shield segments and systematically studying the adaptability and particularity of several different methods have important theoretical significance and application value.

[0007] The current test platforms for post-grouting detection behind shield segments are relatively single, and the combination of multiple scenarios, multiple strata, and multiple defects has not been realized; moreover, the method for generating defects is relatively primitive, with low construction efficiency and poor reliability. Summary of the Invention

[0008] To solve the above problems, on the one hand, the present application proposes a test device for post-grouting detection behind shield segments, which includes an inner detection cavity. A shield segment layer is arranged around the outside of the inner detection cavity, a mortar layer is arranged outside the shield segment layer, and an external enclosure unit is arranged outside the mortar layer. By building a shield segment model, the present application can conveniently set various types of defect parts in the mortar layer, systematically explore the characterization forms and characteristics of various detection methods for the defect parts, and combine the actual test results to reverse-infer information such as the scale, position, shape, and type of the actual defect parts, providing a basis for accurately determining the defect parts of the tunnel.

[0009] Preferably, the external enclosure unit includes a rock section, an undisturbed soil section, and a support form section arranged in sequence.

[0010] Preferably, a reserved space is also included in the mortar layer and the external enclosure unit, and the reserved space is communicated with the shield segment layer.

[0011] Preferably, a transition section is arranged between the rock section and the undisturbed soil section. The transition section includes a rock connecting block connected to the rock section and a soil connecting block connected to the undisturbed soil section, and the rock connecting block and the soil connecting block are arranged alternately.

[0012] Preferably, the rock section and the undisturbed soil section are compacted, and the sides of the rock section and the undisturbed soil section facing the shield segment layer are arranged vertically.

[0013] Preferably, the shield segment layer includes a number of segment bodies arranged in a staggered manner, and the segment bodies are connected by connecting bolts; a partition board is arranged at the lower part of the mortar layer.

[0014] Preferably, the thickness of the mortar layer is 200 - 300 mm;

[0015] The thickness of the external enclosure unit is not less than 400 mm;

[0016] The segment layer of the shield tunneling includes two segment bodies in the height direction, and the height of each segment body is 1000 - 2000 mm;

[0017] The height of the mortar layer and the external enclosure unit is 1500 - 2000 mm.

[0018] Preferably, defect sites are provided at the positions of the mortar layer corresponding to the rock section and / or the undisturbed soil section and / or the support formwork section; the shapes of the defect sites are strip-shaped or dot-shaped or sheet-shaped;

[0019] The defect sites are hole defects and / or crack defects and / or water-rich defects;

[0020] The defect sites are set near the segment layer of the shield tunneling or near the external enclosure unit or in the middle of the mortar layer;

[0021] The mortar layer is obtained as follows:

[0022] Configure shield mortar, and add ceramic hollow balls to the shield mortar to obtain functional mortar;

[0023] Use the functional mortar to pour at the positions where defect sites need to be set to obtain defect sites, and pour shield mortar above and / or below the defect sites to obtain normal sites;

[0024] The defect sites and the normal sites are arranged at intervals;

[0025] Maintain the defect sites and the normal sites to obtain the mortar layer. By setting the functional mortar in this application, defect sites of a certain type can be obtained, with high construction efficiency, providing test objects for the later test verification of various detection methods.

[0026] Preferably, the shield mortar includes raw materials in the following parts by mass:

[0027] Cement: 260 - 280 parts;

[0028] Fly ash: 25 - 35 parts;

[0029] River sand: 450 - 550 parts;

[0030] Heavy calcium powder: 150 - 200 parts;

[0031] Gypsum powder: 25 - 35 parts;

[0032] Polycarboxylate water reducer: 3 - 5 parts;

[0033] Organic silicon defoamer: 0.4 - 0.6 parts;

[0034] Suspension stabilizer: 0.2 - 0.4 parts;

[0035] Cellulose ether: 0.2 - 0.4 parts;

[0036] Water - cement ratio: 0.25 - 0.35;

[0037] The cement is P.O42.5 ordinary Portland cement;

[0038] The particle size of the river sand is 70 - 120 mesh;

[0039] The particle size of the heavy calcium powder is 150 - 200 mesh;

[0040] The gypsum powder is hemihydrate gypsum powder;

[0041] The cellulose ether is 400 - viscosity cellulose ether;

[0042] The ceramic hollow spheres are also functionalized to obtain functional ceramic hollow spheres in the following way:

[0043] Select ceramic hollow spheres with a particle size of 18 - 30 mesh, place the ceramic hollow spheres in a 5 - 10wt% sodium silicate solution, stir and then fish them out and put them into the water - absorbent resin until the surfaces of the ceramic hollow spheres are all covered with the water - absorbent resin;

[0044] The shape of the defective part is achieved by controlling the shaping position of the ceramic hollow spheres;

[0045] The pore defects are obtained in the following way: Put ceramic hollow spheres into the shield mortar to form functional mortar. The mass fraction of the ceramic hollow spheres is: 500 - 550 parts, and after shaping and curing, the defective parts of the pore defect type are obtained;

[0046] The water - rich defects are obtained in the following way: Put ceramic hollow spheres filled with water inside into the shield mortar to form functional mortar. The mass fraction of the ceramic hollow spheres (including the internal water) is: 1000 - 1100 parts, and after shaping and curing, the defective parts of the water - rich defect type are obtained;

[0047] The crack defects are obtained in the following way: Put functional ceramic hollow spheres into the shield mortar to form functional mortar. The mass fraction of the functional ceramic hollow spheres is: 200 - 250 parts, and after shaping and curing, the defective parts of the crack defect type are obtained. The ceramic hollow spheres of the present application can be modified with water - absorbent resin according to needs, which can make the water - absorbent resin more enriched. After enrichment, it has an effect of hindering the shaping of the mortar itself, thus providing a material basis for the formation of subsequent crack - defective parts.

[0048] On the other hand, the present application also discloses a preparation method of a back - filling grouting detection test device for shield segments, including the following steps:

[0049] Excavate a foundation pit;

[0050] Set the rock section, undisturbed soil section, and support formwork section in the foundation pit according to the design requirements;

[0051] Then set the shield segment layer;

[0052] Pour functional mortar into the space between the shield segment layer and the rock section, undisturbed soil section, and support formwork section to obtain the defective part, and pour shield mortar to obtain the normal part, and finally obtain the mortar layer;

[0053] Conduct inspection tests on the mortar layer.

[0054] 1. By constructing a shield segment model, this application can conveniently set various types of defective parts in the mortar layer, systematically explore the characterization forms and characteristics of various detection methods for defective parts, and based on the actual detection results, reverse-infer information such as the scale, location, shape, and type of the actual defective parts, providing a basis for accurately determining the defective parts of the tunnel.

[0055] 2. By setting functional mortar, this application can obtain defective parts of determined types, thus providing test objects for the subsequent detection and verification of various detection methods.

[0056] 3. The ceramic hollow balls of this application can be modified with water-absorbing resin as needed, which can make the water-absorbing resin more enriched. After enrichment, it has an inhibitory effect on the forming of the mortar itself, thus providing a material basis for the formation of subsequent crack defective parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0058] Figure 1 is a schematic structural diagram of the present application.

[0059] Figure 2 is a top view schematic diagram of the present application.

[0060] Figure 3 is a cross-sectional view of the undisturbed soil section part.

[0061] Figure 4 is a cross-sectional view of the rock section part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0062] To clearly illustrate the technical features of this solution, the present application will be elaborated in detail below through specific embodiments and in combination with its drawings.

[0063] In terms of structure, as Figures 1-4As shown in the figure, a grouting detection test device behind the segment of a shield tunneling machine includes an inner detection cavity 1. A shield segment layer 2 is arranged around the outside of the inner detection cavity 1. A mortar layer 3 is arranged outside the shield segment layer 2. An external enclosure unit 4 is arranged outside the mortar layer 3.

[0064] The external enclosure unit 4 includes a rock section 5, an undisturbed soil section 6, and a support formwork section 7 arranged in sequence. In the mortar layer 3 and the external enclosure unit 4, there is also a reserved space 8 arranged in communication. The reserved space 8 is arranged in communication with the shield segment layer 2. A transition section is arranged between the rock section 5 and the undisturbed soil section 6. The transition section includes a rock connecting block connected to the rock section 5 and a soil connecting block connected to the undisturbed soil section 6. The rock connecting block and the soil connecting block are arranged in an alternating manner. The rock section 5 and the undisturbed soil section 6 are compacted. The sides of the rock section 5 and the undisturbed soil section 6 facing the shield segment layer 2 are arranged vertically.

[0065] The shield segment layer 2 includes a number of segment bodies 9 arranged with staggered joints. The segment bodies 9 are connected by connecting bolts. An isolation plate 10 is arranged at the lower part of the mortar layer 3. The isolation plate 10 is beneficial for isolating from the foundation part and quickly replacing the mortar layer.

[0066] The thickness of the mortar layer 3 is 200 - 300 mm; the thickness of the external enclosure unit 4 is not less than 400 mm; the shield segment layer 2 includes two segment bodies 9 in the height direction. The height of each segment body 9 is 1000 - 2000 mm; the height of the mortar layer 3 and the external enclosure unit 4 is 1500 - 2000 mm.

[0067] Defect parts 11 are arranged at the position of the mortar layer 3 corresponding to the rock section 5 and / or the undisturbed soil section 6 and / or the support formwork section 7; the shape of the defect parts 11 is strip-shaped or dot-shaped or sheet-shaped; the defect parts 11 are hole defects and / or crack defects and / or water-rich defects; the defect parts 11 are set near the shield segment layer 2 or near the external enclosure unit 4 or arranged in the middle of the mortar layer 3.

[0068] S101. The functionalized ceramic hollow spheres are prepared as follows:

[0069] Select ceramic hollow spheres with a particle size of 18 - 30 mesh. Place the ceramic hollow spheres in a sodium silicate solution with a concentration of 5 - 10 wt%. After stirring, take them out and put them into the water-absorbing resin until the surfaces of the ceramic hollow spheres are all covered with the water-absorbing resin.

[0070] S102. Prepare shield mortar, and add ceramic hollow spheres (including functionalized ceramic hollow spheres) to the shield mortar to obtain functional mortar.

[0071] The shield mortar includes raw materials in the following mass parts:

[0072] P.O 42.5 ordinary portland cement: 260 - 280 parts;

[0073] Fly ash: 25 - 35 parts;

[0074] River sand with a particle size of 70 - 120 mesh: 450 - 550 parts;

[0075] Heavy calcium powder with a particle size of 150 - 200 mesh: 150 - 200 parts;

[0076] Semi - hydrated gypsum powder: 25 - 35 parts;

[0077] Polycarboxylate water - reducing agent: 3 - 5 parts;

[0078] Organosilicon defoamer: 0.4 - 0.6 parts;

[0079] Suspension stabilizer: 0.2 - 0.4 parts;

[0080] 400 - viscosity cellulose ether: 0.2 - 0.4 parts;

[0081] Water - cement ratio: 0.25 - 0.35;

[0082] S103. The shape of the defective part is achieved by controlling the plasticizing position of the ceramic hollow spheres;

[0083] At the position where the defective part needs to be set, the defective part is obtained by pouring functional mortar, and the normal part is obtained by pouring shield mortar above and / or below the defective part;

[0084] The defective part and the normal part are arranged at intervals;

[0085] The defective part and the normal part are cured to obtain a mortar layer.

[0086] For specific defects, the hole defect is obtained as follows: Ceramic hollow spheres are put into the shield mortar to form functional mortar. The mass fraction of the ceramic hollow spheres is: 500 - 550 parts, and after plasticizing and curing, the defective part of the hole defect type is obtained;

[0087] The water - rich defect is obtained as follows: Ceramic hollow spheres filled with water are put into the shield mortar to form functional mortar. The mass fraction of the ceramic hollow spheres (including the internal water) is: 1000 - 1100 parts, and after plasticizing and curing, the defective part of the water - rich defect type is obtained;

[0088] The crack defect is obtained as follows: Functionalized ceramic hollow spheres are put into the shield mortar to form functional mortar. The mass fraction of the functionalized ceramic hollow spheres is: 200 - 250 parts, and after plasticizing and curing, the defective part of the crack defect type is obtained.

[0089] S104. Cure the defective parts and normal parts for 28 days to obtain a mortar layer.

[0090] The overall construction plan is as follows:

[0091] S201. Excavate the foundation pit;

[0092] S202. Set a rock section with a thickness of not less than 400 mm, an undisturbed soil section with a thickness of not less than 400 mm, and a support formwork section in the foundation pit according to the design requirements;

[0093] S203. Then set a shield segment layer composed of segment bodies. The height of each segment body is 1000 - 2000 mm, and the segment bodies are connected by bolts;

[0094] S204. Pour functional mortar into the space between the shield segment layer and the rock section, undisturbed soil section, and support formwork section to obtain the defective parts, and pour shield mortar to obtain the normal parts, finally obtaining a mortar layer with a thickness of 200 - 300 mm;

[0095] S205. For the defective parts of the mortar layer, since the determined positions have been obtained during the processing, the determined positions can be detected and tested, and the detection effects of the corresponding defective parts can be obtained.

[0096] During the specific construction, it is processed in the following manner:

[0097] Example 1:

[0098] S1201. Excavate the foundation pit;

[0099] S1202. Set a rock section with a thickness of 400 mm, an undisturbed soil section with a thickness of 400 mm, and a support formwork section (the support formwork can be removed according to needs to be the air layer) in the foundation pit according to the design requirements, and the height corresponds to that of the shield segment layer;

[0100] S1203. Set a shield segment layer composed of segment bodies in the mortar layer. The height of each segment body is 1000 mm, and two layers are set in the height direction. The segment bodies are connected by bolts;

[0101] S1204. Pour functional mortar into the space between the shield segment layer and the rock section, undisturbed soil section, and support formwork section to obtain the defective parts, and pour shield mortar to obtain the normal parts, finally obtaining a mortar layer with a thickness of 200 mm; In order to facilitate removal, a partition board can be set at the lower part of the mortar layer;

[0102] S12041. The functionalized ceramic hollow spheres are prepared in the following manner:

[0103] Select ceramic hollow spheres with a particle size of 18-30 mesh, place the ceramic hollow spheres in a 5wt% sodium silicate solution, stir, then fish them out and put them into the water-absorbing resin until the surface of the ceramic hollow spheres is covered with the water-absorbing resin;

[0104] S12042. Prepare shield mortar, and add ceramic hollow spheres (including functionalized ceramic hollow spheres) to the shield mortar to obtain functional mortar;

[0105] The shield mortar includes the following raw materials in parts by mass:

[0106] P.O42.5 ordinary portland cement: 260 parts;

[0107] Fly ash: 25 parts;

[0108] River sand with a particle size of 70-120 mesh: 450 parts;

[0109] Heavy calcium powder with a particle size of 150-200 mesh: 150 parts;

[0110] Hemihydrate gypsum powder: 25 parts;

[0111] Polycarboxylate water reducer: 3 parts;

[0112] Organosilicon defoamer: 0.4 part;

[0113] Suspension stabilizer: 0.2 part;

[0114] 400-viscosity cellulose ether: 0.2 part;

[0115] Water-cement ratio: 0.25;

[0116] S12043. The shape of the defective part is achieved by controlling the shaping position of the ceramic hollow spheres (including functionalized ceramic hollow spheres);

[0117] The hole defect is obtained in the following manner: put ceramic hollow spheres into the shield mortar to form functional mortar, the mass of the ceramic hollow spheres is: 500 parts, and after shaping and curing, a defective part of the hole defect type is obtained;

[0118] The water-rich defect is obtained in the following manner: put ceramic hollow spheres filled with water into the shield mortar to form functional mortar, the mass of the ceramic hollow spheres (including the internal water) is: 1000 parts, and after shaping and curing, a defective part of the water-rich defect type is obtained;

[0119] The crack defect is obtained in the following manner: put functionalized ceramic hollow spheres into the shield mortar to form functional mortar, the mass of the functionalized ceramic hollow spheres is: 200 parts, and after shaping and curing, a defective part of the crack defect type is obtained.

[0120] During specific construction, for the shield mortar, first mix all the solid components evenly, then add water and stir before pouring;

[0121] For the functional mortar, first mix the solid components and the required ceramic hollow spheres or functionalized ceramic hollow spheres evenly, then add water and stir before pouring;

[0122] First, pour a 300 - mm - high mortar layer at the bottom to form a normal part;

[0123] Then, pour a 300 - mm - high mortar layer of the hole - defect type from the upper part to form a hole - defect part;

[0124] Pour another 300 - mm - high mortar layer to form a normal part;

[0125] Then, continue to pour a 300 - mm - high mortar layer of the water - rich defect type from the upper part to form a water - rich defect part;

[0126] Pour another 300 - mm - high mortar layer to form a normal part;

[0127] Then, continue to pour a 300 - mm - high mortar layer of the crack - defect type from the upper part to form a crack - defect part.

[0128] S12044. Cure the defect parts and normal parts for 28 days to obtain the mortar layer.

[0129] S1205. For the defect parts of the mortar layer, since the positions have been determined during the processing, the determined positions can be subjected to detection tests, and the detection effects of the corresponding defect parts can be obtained.

[0130] Detect the hole - defect type, water - rich defect type, and crack - defect type, which meet the requirements for the defects.

[0131] Example 2:

[0132] S2201. Excavate the foundation pit;

[0133] S2202. Set a rock section with a thickness of 800 mm, an undisturbed soil section with a thickness of 800 mm, and a support - form section (the support form can be removed according to needs to form an air layer) in the foundation pit according to the design requirements, and the height corresponds to the shield - segment layer;

[0134] S2203. Set a shield - segment layer composed of segment bodies in the mortar layer. The height of each segment body is 2000 mm, and a single layer is arranged in the height direction. The segment bodies are connected by bolts;

[0135] S2204. Pour functional mortar into the space between the shield segment layer and the rock section, the undisturbed soil section, and the support formwork section to obtain the defective part, and pour shield mortar to obtain the normal part, finally obtaining a mortar layer with a thickness of 300 mm; for easy removal, a separator can be set at the lower part of the mortar layer;

[0136] S22041. The functional ceramic hollow spheres are prepared as follows:

[0137] Select ceramic hollow spheres with a particle size of 18 - 30 mesh, place the ceramic hollow spheres in a 10wt% sodium silicate solution, stir and then fish them out and put them into the water-absorbing resin until the surface of the ceramic hollow spheres is covered with water-absorbing resin;

[0138] S22042. Prepare shield mortar, and add ceramic hollow spheres (including functional ceramic hollow spheres) to the shield mortar to obtain functional mortar;

[0139] The shield mortar includes the following raw materials in parts by mass:

[0140] P.O42.5 ordinary Portland cement: 280 parts;

[0141] Fly ash: 35 parts;

[0142] River sand with a particle size of 70 - 120 mesh: 550 parts;

[0143] Heavy calcium powder with a particle size of 150 - 200 mesh: 200 parts;

[0144] Hemihydrate gypsum powder: 35 parts;

[0145] Polycarboxylate water reducer: 5 parts;

[0146] Organosilicon defoamer: 0.6 part;

[0147] Suspension stabilizer: 0.4 part;

[0148] 400-viscosity cellulose ether: 0.4 part;

[0149] Water-cement ratio: 0.35;

[0150] S22043. The shape of the defective part is achieved by controlling the shaping position of the ceramic hollow spheres (including functional ceramic hollow spheres);

[0151] The hole defect is obtained as follows: put ceramic hollow spheres into the shield mortar to form functional mortar, the mass fraction of the ceramic hollow spheres is: 550 parts, and after shaping and curing, a defective part of the hole defect type is obtained;

[0152] The water-rich defect is obtained in the following manner: Functional mortar is formed by putting ceramic hollow balls filled with water into shield mortar. The mass fraction of the ceramic hollow balls is: 1100 parts. After shaping and curing, a defect part of the water-rich defect type is obtained.

[0153] The crack defect is obtained in the following manner: Functional mortar is formed by putting functionalized ceramic hollow balls into shield mortar. The mass fraction of the functionalized ceramic hollow balls is: 250 parts. After shaping and curing, a defect part of the crack defect type is obtained.

[0154] During specific construction, for shield mortar, first mix all the solid components evenly, then add water and stir before pouring.

[0155] For functional mortar, first mix the solid components and the required ceramic hollow balls or functionalized ceramic hollow balls evenly, then add water and stir before pouring.

[0156] First, pour a mortar layer with a height of 300 mm at the bottom to form a normal part.

[0157] Then, pour a mortar layer with a height of 300 mm of the hole defect type from the upper part to form a hole defect part.

[0158] Pour another mortar layer with a height of 300 mm to form a normal part.

[0159] Then, continue to pour a mortar layer with a height of 300 mm of the water-rich defect type from the upper part to form a water-rich defect part.

[0160] Pour another mortar layer with a height of 300 mm to form a normal part.

[0161] Then, continue to pour a mortar layer with a height of 300 mm of the crack defect type from the upper part to form a crack defect part.

[0162] S22044. Cure the defect parts and normal parts for 28 d to obtain a mortar layer.

[0163] S2205. For the defect parts of the mortar layer, since their positions have been determined during the processing, the determined positions can be subjected to detection tests to obtain the detection effects of the corresponding defect parts.

[0164] Detect the hole defect type, water-rich defect type, and crack defect type, and they meet the requirements for the defects.

[0165] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A grouting detection test device behind the segment of a shield tunneling machine, characterized in that: It includes an internal detection cavity, and a shield segment layer is disposed around the outside of the internal detection cavity. A mortar layer is provided on the outside of the shield segment layer, and an external enclosure unit is arranged outside the mortar layer.

2. The grouting detection test device behind the segment lining of a shield tunneling machine according to claim 1, wherein: The external enclosure unit includes a rock section, an undisturbed soil section, and a support formwork section arranged in sequence.

3. The grouting detection test device behind the segment lining of a shield tunneling machine according to claim 2, characterized in that: In the mortar layer and the external enclosure unit, there is also a reserved space connected in communication, and the reserved space is connected to the shield segment layer.

4. The shield segment grouting detection test device according to claim 2, characterized in that: A transition section is arranged between the rock section and the undisturbed soil section. The transition section includes a rock connection block connected to the rock section and a soil connection block connected to the undisturbed soil section, and the rock connection block and the soil connection block are arranged in an alternating manner.

5. The grouting detection test device behind the segment of a shield tunneling machine according to claim 2, characterized in that: The rock section and the undisturbed soil section are compacted, and the sides of the rock section and the undisturbed soil section facing the shield segment layer are arranged vertically.

6. The post - grouting detection test device for the segment behind the shield tunneling lining according to claim 1, characterized in that: The shield segment layer includes a number of segment bodies connected in a staggered manner, and the segment bodies are connected by connecting bolts; a partition board is arranged at the lower part of the mortar layer.

7. The testing device for the grouting behind the segment lining of a shield tunneling machine according to claim 6, characterized in that: The thickness of the mortar layer is 200 - 300 mm; The thickness of the external enclosure unit is not less than 400 mm; The shield segment layer includes two segment bodies in the height direction, and the height of each segment body is 1000 - 2000 mm; The height of the mortar layer and the external enclosure unit is 1500 - 2000 mm.

8. The post - grouting detection test device for the segment behind the shield as described in claim 1, wherein: Defect sites are arranged at the positions of the mortar layer corresponding to the rock section and / or the undisturbed soil section and / or the support formwork section; the shape of the defect sites is strip-shaped or dot-shaped or sheet-shaped; The defect sites are hole defects and / or crack defects and / or water-rich defects; The defect sites are set near the shield segment layer or near the external enclosure unit or arranged in the middle of the mortar layer; The mortar layer is obtained in the following manner: Configure shield mortar, and add ceramic hollow spheres to the shield mortar to obtain functional mortar; Use the functional mortar to pour at the positions where defect sites need to be arranged to obtain the defect sites, and pour shield mortar above and / or below the defect sites to obtain normal parts; The defect sites and the normal parts are arranged at intervals; Carry out curing on the defect sites and the normal parts to obtain the mortar layer.

9. The testing device for the backfilling grouting of a shield segment according to claim 8, wherein: The shield mortar includes raw materials in the following mass parts: Cement: 260 - 280 parts; Fly ash: 25 - 35 parts; River sand: 450 - 550 parts; Heavy calcium powder: 150 - 200 parts; Gypsum powder: 25 - 35 parts; Polycarboxylate superplasticizer: 3 - 5 parts; Organic silicon defoamer: 0.4 - 0.6 parts; Suspension stabilizer: 0.2 - 0.4 parts; Cellulose ether: 0.2 - 0.4 parts; Water-cement ratio: 0.25 - 0.35; The cement is P.O42.5 ordinary Portland cement; The particle size of the river sand is 70 - 120 mesh; The particle size of the heavy calcium powder is 150 - 200 mesh; The gypsum powder is hemihydrate gypsum powder; The cellulose ether is 400-viscosity cellulose ether; The ceramic hollow spheres are also functionalized in the following manner to obtain functionalized ceramic hollow spheres: Select ceramic hollow spheres with a particle size of 18 - 30 mesh, place the ceramic hollow spheres in a 5 - 10 wt% sodium silicate solution, stir and then fish them out and put them into the water-absorbing resin until the surfaces of the ceramic hollow spheres are all covered with the water-absorbing resin; The shape of the defective part is achieved by controlling the shaping position of the ceramic hollow spheres; The hole defects are obtained as follows: Ceramic hollow spheres are put into the shield mortar to form a functional mortar. The mass fraction of the ceramic hollow spheres is 500 - 550 parts. After shaping and curing, a defective part of the hole defect type is obtained; The water-rich defects are obtained as follows: Ceramic hollow spheres filled with water are put into the shield mortar to form a functional mortar. The mass fraction of the water-containing ceramic hollow spheres is 1000 - 1100 parts. After shaping and curing, a defective part of the water-rich defect type is obtained; The crack defects are obtained as follows: Functionalized ceramic hollow spheres are put into the shield mortar to form a functional mortar. The mass fraction of the functionalized ceramic hollow spheres is 200 - 250 parts. After shaping and curing, a defective part of the crack defect type is obtained.

10. A preparation method of a grouting detection test device behind the segment of a shield tunneling machine according to any one of claims 9, characterized in that: It includes the following steps: Excavate the foundation pit; Set the rock section, undisturbed soil section, and support formwork section in the foundation pit according to the design requirements; Then set the shield segment layer; Pour the functional mortar into the space between the shield segment layer and the rock section, undisturbed soil section, and support formwork section to obtain the defective part, and pour the shield mortar to obtain the normal part, finally obtaining the mortar layer; Conduct inspection tests on the mortar layer.

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