Single ring pipe piece wall synchronous alternate grouting shield construction method

Abstract

The present application relates to the technical field of shield construction, and particularly relates to a single-ring segment wall synchronous alternating grouting shield construction method, wherein fast-setting slurry with initial setting time of 7-8 minutes is obtained in a laboratory, and then the initial setting time of the fast-setting slurry is further adjusted to 10 minutes on a double-liquid grouting device, and the construction ratio is adopted in actual construction, and synchronous alternating grouting construction is carried out on the single-ring segment wall under three special conditions of shield launching, shield receiving and water-rich geology, so that the deficiencies of the existing conventional single-liquid grouting or double-liquid grouting under special conditions are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shield construction, in particular to a single-ring segment wall synchronous alternate grouting shield construction method. BACKGROUND

[0002] Synchronous grouting is used to fill the gap between the shield machine body and the segment, which is a conventional and necessary process in current shield construction. The conventional synchronous grouting adopts single liquid slurry. Since the single liquid slurry has fluidity and a long setting time, its use effect is affected in the following special working conditions: 1. When the shield starts and receives, the single liquid slurry cannot be timely and synchronously injected near the segment wall of the portal, resulting in an increase in the workload of sealing the portal in the later period; 2. When the shield passes through water-rich geology, the single liquid slurry in the grouting area cannot quickly solidify, resulting in the formation of a water passage in the stratum, and underground water will affect the grouting area, so that the assembled segment and the stratum cannot be quickly and stably fixed, thereby producing a series of adverse factors affecting the quality and safety of the shield. In order to avoid the defects of the conventional single liquid slurry, the current improved method is to use cement slurry and water glass to form double liquid slurry that can quickly solidify for synchronous grouting construction. However, this method has the following disadvantages: material cost increases; different slurries need to be prepared and transported to the construction site at any time, which brings the disadvantages of complex management and process; the double liquid slurry formed by mixing cement slurry and water glass has a short setting time, which easily causes the grouting pipeline to be blocked, affecting the construction efficiency; and the double liquid slurry is used in the whole single-ring segment wall, which will cause the slurry and the shield tail sealing brush to solidify together when the shield stops advancing and assembling the segment, thereby causing great damage to the shield tail sealing brush when the shield machine resumes advancing. SUMMARY

[0003] The present application provides a single-ring segment wall synchronous alternate grouting shield construction method to solve the problems in the prior art.

[0004] The present application is implemented by the following technical solutions:

[0005] A single-ring segment wall synchronous alternate grouting shield construction method, comprising the following steps:

[0006] Step 1: add water to the water glass stock solution in the laboratory to form a water glass mixed solution, add the water glass mixed solution to the single liquid slurry to form a quick-setting slurry, and adjust the ratio of the water glass mixed solution and the single liquid slurry to make the initial setting time of the quick-setting slurry 7-8 min to determine the experimental ratio of the quick-setting slurry; if the above-mentioned addition of the water glass mixed solution to the single liquid slurry cannot make the initial setting time of the quick-setting slurry 7-8 min, then add cement to the single liquid slurry to form a quick-setting slurry, and adjust the ratio of the water glass mixed solution, the single liquid slurry, and the cement to make the initial setting time of the quick-setting slurry 7-8 min to determine the experimental ratio of the quick-setting slurry;

[0007] Step two: the fast-setting slurry experimental ratio determined in step one is pumped through the double-liquid grouting equipment, and then the initial setting time of the fast-setting slurry is tested in a natural state, the ratio of the pumped single-liquid slurry and water glass mixture is fine-tuned until the initial setting time of the fast-setting slurry pumped through the double-liquid grouting equipment is 10 min, and the fast-setting slurry construction ratio is determined;

[0008] Step three: during shield launching, the single-liquid slurry and water glass mixture are synchronously pumped in a double-liquid grouting mode when the second ring is excavated for 3 / 4 of the ring length, the ratio of the single-liquid slurry and water glass mixture is the fast-setting slurry construction ratio determined in step two, when the shield machine excavates beyond 3 / 4 of the ring length of the second ring, the water glass mixture is stopped from being pumped, the water glass mixture pipeline is immediately cleaned with clean water, and the single-liquid slurry is continuously pumped until the ring excavation is completed.

[0009] Step four: during shield receiving, the third ring from the end and the second ring from the end are both pumped in a double-liquid grouting mode of single-liquid slurry and water glass mixture for 3 / 4 of the ring length, and the last 1 / 4 of the ring is pumped in a single-liquid grouting mode; the last ring during shield receiving is pumped in a double-liquid grouting mode of single-liquid slurry and water glass mixture for 3 / 4 of the ring length, and the remaining 1 / 4 of the ring is stopped from being pumped, and the shield tail is directly pushed out of the tunnel portal.

[0010] Step five: if water-rich geology is encountered during shield construction, the single-liquid slurry and water glass mixture are synchronously pumped in a double-liquid grouting mode for 1 / 2 of the ring length when the shield machine passes through water-rich geology, the water glass mixture is stopped from being pumped when the shield machine excavates beyond 1 / 2 of the ring length, the water glass mixture pipeline is immediately cleaned with clean water, the single-liquid slurry is continuously pumped until the ring excavation is completed, then the shield machine stops excavating, the segments are assembled, and after the segment assembly is completed, the next ring is excavated and the above process is repeated; when the geological conditions improve, the single-liquid slurry and water glass mixture are synchronously pumped in a double-liquid grouting mode for 1 / 3 of the ring length, and the single-liquid slurry is continuously pumped for the remaining 2 / 3 of the ring until the ring excavation is completed; when the geological conditions completely improve, the single-liquid slurry is synchronously pumped in a single-liquid grouting mode.

[0011] Step six: in addition to the three working conditions of shield launching, shield receiving and water-rich geology, each ring in other working conditions is normally excavated in a conventional single-liquid slurry synchronous grouting mode.

[0012] As a preferred scheme of the present application:

[0013] In step one, the water glass stock solution with a Baume degree of 35-38°Bé is selected.

[0014] In step one, 50-100 kg of cement is added to each cubic meter of single-liquid slurry.

[0015] In step two, the ratio of the pumped single-liquid slurry and water glass mixture is fine-tuned during the shield machine installation and debugging stage or when the negative ring segments are assembled.

[0016] In the third step, the synchronous double-liquid grouting pressure is 1-4 Bar when excavating the first 3 / 4 ring length of the second ring.

[0017] In the fifth step, the synchronous single-liquid grouting pressure is controlled at 4 Bar, and the synchronous double-liquid grouting pressure is controlled at 5-6 Bar.

[0018] The present application aims at the shortcomings of the prior art, and obtains a fast-setting slurry with an initial setting time of 7-8 minutes in a laboratory through experiments, determines the laboratory ratio of the single-liquid slurry and the sodium silicate mixed liquid, further adjusts the fast-setting slurry with an initial setting time of 10 minutes on a double-liquid grouting device before construction, determines the construction ratio of the fast-setting slurry, and adopts the construction ratio in actual construction. The fast-setting slurry has the characteristics of rapid setting, and is used for synchronous and alternate grouting construction behind the single-ring segment in three special working conditions of shield launching, shield receiving and water-rich geology, so as to solve many shortcomings of the existing conventional single-liquid grouting or double-liquid grouting in special working conditions.

[0019] The present application uses the fast-setting slurry and the single-liquid slurry (fast setting and slow setting) for synchronous and alternate grouting for the first time in shield tunneling construction, and the fast setting and slow setting are alternately switched in the same ring, which is simple and easy to implement. The fast-setting slurry is not easy to block the pipeline, and the fast-setting slurry wraps 1 / 3-3 / 4 of the length of each ring segment. In the special working conditions and the poor geological conditions, the alternate "fast-setting zone" + "transition zone" + "slow-setting zone" is formed around the periphery of the segment tunnel. The fast-setting slurry wrapped around the segment can quickly set, which can quickly stabilize the segment and the stratum, form a water-stopping ring, block the water behind, and prevent the segment from floating up. The slow-setting zone is constructed by using the conventional synchronous single-liquid grouting of the shield, and the construction method of the present application avoids the problems of blocking the grouting pipeline and causing great damage to the shield tail sealing brush caused by the too fast setting time of the conventional double-liquid slurry. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the application of the present application in the shield launching working condition.

[0021] Figure 2 It is a schematic diagram of the application of the present application in the water-rich geological working condition.

[0022] Figure 3 It is a schematic diagram of the application of the present application in the shield receiving working condition. DETAILED DESCRIPTION

[0023] The specific embodiments of the present application are given below in combination with the drawings, and it should be noted that the present application is not limited to the following specific embodiments, and any equivalent variations made on the basis of the technical solutions of the present application are within the protection scope of the present application.

[0024] The single-ring pipe piece wall back-synchronous alternate grouting shield construction method of the present application comprises the following steps:

[0025] Step one: determining the experimental proportion of the quick-setting slurry

[0026] A certain amount of water is added to the water glass stock solution in the laboratory to form a water glass mixed solution, the water glass stock solution can be a commercially available water glass stock solution, then the water glass mixed solution is added to the single-liquid slurry commonly used in shield construction for mixing to form a quick-setting slurry, and the addition ratio is adjusted so that the initial setting time of the final quick-setting slurry is 7-8 min. The initial setting time of the single-liquid slurry commonly used in shield construction on the construction site is generally 6-10 h, and the final initial setting time is shortened to 7-8 min by adding the water glass mixed solution. If the addition of the water glass mixed solution alone cannot make the initial setting time of the quick-setting slurry reach 7-8 min, then in addition to the water glass mixed solution, cement is also added to form a quick-setting slurry, i.e. the single-liquid slurry, the water glass mixed solution, and the cement are mixed to form a quick-setting slurry, and the addition ratio of the three is adjusted so that the initial setting time of the final quick-setting slurry is 7-8 min. According to experience, about 50-100 kg of cement is added per cubic single-liquid slurry to adjust the initial setting time of the quick-setting slurry to 7-8 min.

[0027] Preferably, a water glass stock solution with a Baume degree of 35-38°Bé is selected.

[0028] Step two: determining the construction proportion of the quick-setting slurry

[0029] The double-liquid grouting equipment of the shield machine is adjusted. First, the unit time pumping capacity of the single-liquid slurry pump and the water glass mixed solution pump of the double-liquid grouting equipment is checked and calibrated using clean water. Then, the single-liquid slurry pump is used to pump the single-liquid slurry through the single-liquid slurry pipeline and the water glass mixed solution pump is used to pump the water glass mixed solution through the water glass mixed solution pipeline according to the experimental proportion of the quick-setting slurry determined in step one. The single-liquid slurry pipeline and the water glass mixed solution pipeline will intersect and merge together. The single-liquid slurry and the water glass mixed solution pumped according to the experimental proportion are mixed by the double-liquid grouting equipment to form a quick-setting slurry. Then, the initial setting time of the quick-setting slurry is tested under natural conditions. If the initial setting time of the quick-setting slurry is not 10 min, the pumping proportion of the single-liquid slurry and the water glass mixed solution is adjusted until the initial setting time of the quick-setting slurry pumped by the double-liquid grouting equipment is 10 min. Finally, the construction proportion of the single-liquid slurry and the water glass mixed solution is determined.

[0030] The reason why the initial setting time of the quick-setting slurry is adjusted to 7-8 minutes in the laboratory and the initial setting time of the quick-setting slurry pumped in the actual construction is adjusted to 10 minutes is that the mixing conditions in the laboratory and the actual pumping conditions are different. If the initial setting time of the quick-setting slurry in the laboratory is 7-8 minutes, the initial setting time of the quick-setting slurry pumped through the double-liquid grouting equipment is close to 10 minutes. The actual need in the shield construction is that the initial setting time of the quick-setting slurry is 10 minutes.

[0031] The above-mentioned step two single-liquid slurry and water glass mixed liquid ratio adjustment process can be carried out when the shield machine is installed and adjusted or when the negative ring segment is assembled. At this time, the state of the quick-setting slurry pumped through the double-liquid grouting equipment and flowing out of the grouting pipe at the tail of the shield can be directly observed, and the state can be observed to assist in adjusting the initial setting time of the quick-setting slurry.

[0032] Step three: construction when the shield starts

[0033] When the shield starts, the double-liquid grouting mode of synchronous single-liquid slurry and water glass mixed liquid is adopted when the first 3 / 4 ring length of the second ring is excavated, and the mixing ratio of the single-liquid slurry and the water glass mixed liquid is the construction ratio of the quick-setting slurry determined in step two. When the shield excavates more than 3 / 4 ring of the second ring, the pumping of the water glass mixed liquid is stopped, the water glass mixed liquid pipeline is immediately cleaned with clean water, and the single-liquid slurry is continuously pumped until the excavation of the ring is completed, that is, the remaining 1 / 4 ring of the second ring is grouted in the conventional single-liquid slurry synchronous grouting mode (single-liquid grouting mode).

[0034] Preferably, the synchronous double-liquid grouting pressure is 1-4 Bar when the first 3 / 4 ring length of the second ring is excavated.

[0035] Step four: construction when the shield receives

[0036] When the shield receives, the double-liquid grouting mode of synchronous single-liquid slurry and water glass mixed liquid is adopted when the third last ring and the second last ring are advanced, and the last 1 / 4 ring is grouted in the conventional single-liquid grouting mode, that is, the grouting mode of the third last ring and the second last ring is the same as that when the shield starts.

[0037] The double-liquid grouting mode of synchronous single-liquid slurry and water glass mixed liquid is adopted when the first 3 / 4 ring of the last ring (the first last ring) of the shield receiving is advanced, and the remaining 1 / 4 ring is stopped from grouting, that is, the last 1 / 4 ring is neither pumped with single-liquid slurry nor pumped with water glass mixed liquid, and the shield tail is directly pushed out of the portal.

[0038] Step five: construction in water-rich geology

[0039] If the shield machine encounters water-rich geology during the process, the single slurry and water glass mixed liquid synchronous double liquid grouting method is used when the shield machine is in water-rich geology, and the single slurry and water glass mixed liquid synchronous double liquid grouting method is used when the shield machine is in water-rich geology. When the construction is over 1 / 2 ring of each ring, stop pumping the water glass mixed liquid, immediately wash the water glass mixed liquid pipeline with clean water, and the single slurry is pumped synchronously until the end of the ring excavation, and then the shield stops excavation, assembles the pipe piece, and after the pipe piece assembly is completed, the next ring excavation is carried out and the above process is repeated; when the geological conditions improve, the single slurry and water glass mixed liquid synchronous double liquid grouting method is used when the excavation is in the front 1 / 3 ring length of each ring, and the single slurry is pumped synchronously until the end of the ring excavation; when the geological conditions are completely improved, the conventional single slurry synchronous grouting method is used for normal excavation.

[0040] The above-mentioned improvement of geological conditions and complete improvement of geological conditions refer to the situation that the adverse effects of underground water on shield construction are reduced or eliminated. Those skilled in the art can make judgments through shield machine posture, sensor feedback data, and measurement data of the formed pipe piece. It belongs to the judgment of conventional working conditions of shield construction, and will not be repeated here.

[0041] Preferably, the grouting pressure of the single slurry synchronous grouting in step five is controlled at 4 Bar, and the synchronous double liquid grouting pressure is increased by 1-2 Bar, i.e. the synchronous double liquid grouting pressure is controlled at 5-6 Bar. When the synchronous double liquid grouting method is used, the pumping amount of the single slurry pump and the water glass mixed liquid pump not only maintains the construction ratio determined in step two to ensure the pumping ratio of the two liquids, but also matches the shield excavation speed.

[0042] It needs to be specially pointed out that if the shield encounters water-rich geology when starting or receiving, the excavation is carried out according to steps three and four respectively, i.e. according to the working conditions of shield starting and receiving. Because the geological conditions of the portal area have been reinforced or dewatering measures have been taken in advance, the influence of underground water on starting and receiving is relatively small. At this time, the fast-setting characteristics of the fast-setting slurry are used to form a slurry fast-setting zone, and the gap between the shield machine body and the pipe piece is timely blocked, reducing the workload of subsequent blocking of the portal gap.

[0043] Step six: construction other than steps three to five

[0044] In addition to the above-mentioned steps three to five, i.e. in addition to the three working conditions of shield starting, shield receiving and water-rich geology, the single slurry synchronous grouting method is used for normal excavation of each ring in other working conditions.

[0045] The pump for cleaning the water glass mixture pipeline, the pipeline connected with the water glass mixture pipeline and the clean water tank in the above steps can be arranged separately near the intersection of the single slurry pipeline and the water glass mixture pipeline, so as to reduce the amount of cleaning water and improve work efficiency.

[0046] The synchronous alternate grouting mode of steps three to six forms the alternating "quick setting zone" + "transition zone" + "slow setting zone" behind the pipe wall. The region adopting the single slurry and water glass mixture synchronous double liquid grouting mode is the quick setting zone. Since the quick setting slurry mixed by the single slurry and the water glass mixture has a short initial setting time, the quick setting slurry wrapping the pipe can be quickly solidified, which has the effects of quickly stabilizing the stratum, forming a water stop ring, avoiding the formation of a water passing channel and preventing the pipe from floating. When the pumping of the water glass mixture is stopped, the water glass mixture pipeline is immediately cleaned with clean water. The clean water only needs to flush the water glass mixture pipeline once, so as to prevent the pipeline from being blocked. Therefore, the addition of the clean water forms a short transition zone, which does not have a serious impact on the slurry that has been injected and will be injected. The single slurry is pumped all the time during this period. Since the single slurry has a long initial setting time, the region only pumped by the single slurry is the slow setting zone. The grouting construction of the slow setting zone is the same as the conventional single slurry synchronous grouting construction of the shield. The alternate process of the present application avoids the damage to the shield tail sealing brush.

[0047] The above-described embodiments are only one of the preferred specific embodiments of the present application. The usual changes and replacements made by those skilled in the art within the scope of the technical solutions of the present application should be included in the protection scope of the present application.

Claims

1. A single ring pipe piece wall synchronous alternate grouting shield construction method, comprising the following steps: Step one: adding water to the water glass stock solution in the laboratory to form a water glass mixture, adding the water glass mixture to the single liquid slurry to form a quick-setting slurry, adjusting the ratio of the water glass mixture and the single liquid slurry to make the initial setting time of the quick-setting slurry 7-8 minutes, and determining the experimental ratio of the quick-setting slurry; if adding the water glass mixture to the single liquid slurry cannot make the initial setting time of the quick-setting slurry 7-8 minutes, then adding cement to the single liquid slurry to form a quick-setting slurry, adjusting the ratio of the water glass mixture, the single liquid slurry and the cement to make the initial setting time of the quick-setting slurry 7-8 minutes, and determining the experimental ratio of the quick-setting slurry; Step two: pumping the single liquid slurry and the water glass mixture through a double liquid grouting equipment according to the experimental ratio of the quick-setting slurry determined in step one, then testing the initial setting time of the quick-setting slurry in a natural state, fine-tuning the ratio of the pumped single liquid slurry and the water glass mixture until the initial setting time of the quick-setting slurry pumped through the double liquid grouting equipment is 10 minutes, and determining the construction ratio of the quick-setting slurry; Step three: when the shield starts, the single liquid slurry and the water glass mixture are synchronously pumped in a double liquid grouting mode in the first 3 / 4 ring length of the second ring, and the ratio of the single liquid slurry and the water glass mixture is the construction ratio of the quick-setting slurry determined in step two; when the shield has passed through 3 / 4 of the second ring, the pumping of the water glass mixture is stopped, the water glass mixture pipeline is immediately cleaned with clean water, and the single liquid slurry is continuously pumped until the end of the ring excavation; Step four: when the shield is received, the third last ring and the second last ring are both pumped in a double liquid grouting mode of the single liquid slurry and the water glass mixture in the first 3 / 4 ring of each ring, and the last 1 / 4 ring is pumped in a single liquid slurry grouting mode; the last ring when the shield is received is pumped in a double liquid grouting mode of the single liquid slurry and the water glass mixture in the first 3 / 4 ring, and the remaining 1 / 4 ring is stopped from grouting, and the shield tail is directly pushed out of the portal; Step five: if water-rich geology is encountered during the shield process, then when the shield machine passes through the water-rich geology, the single liquid slurry and the water glass mixture are synchronously pumped in a double liquid grouting mode in the first 1 / 2 ring of each ring, when the construction has passed through the first 1 / 2 ring of each ring, the pumping of the water glass mixture is stopped, the water glass mixture pipeline is immediately cleaned with clean water, and the single liquid slurry is continuously pumped until the end of the ring excavation, then the shield stops excavation, the pipe pieces are assembled, after the pipe piece assembly is completed, the next ring excavation is carried out and the above process is repeated; when the geological conditions improve, then the single liquid slurry and the water glass mixture are synchronously pumped in a double liquid grouting mode in the first 1 / 3 ring of each ring, and the single liquid slurry is continuously pumped in the last 2 / 3 ring until the end of the ring excavation; when the geological conditions completely improve, the single liquid slurry is synchronously pumped in a single liquid slurry grouting mode for excavation; Step six: in addition to the three working conditions of shield starting, shield receiving and water-rich geology, each ring in other working conditions is normally excavated in a conventional single liquid slurry synchronous grouting mode.

2. The single cycle pipe wall post-synchronous alternate grouting shield construction method according to claim 1, characterized in that: In the step one, the water glass stock solution with a Baume degree of 35-38°Bé is selected.

3. The single cycle pipe wall post-synchronous alternate grouting shield construction method according to claim 1, characterized in that: In the step one, 50-100 kg of cement is added to each cubic single liquid slurry.

4. The single cycle pipe wall post-synchronous alternate grouting shield construction method according to claim 1, characterized in that: In the step two, the ratio of the pumped single liquid slurry and the water glass mixture is fine-tuned during the shield machine installation and debugging stage or the assembly of the negative ring pipe pieces.

5. The single cycle pipe wall post-synchronous alternate grouting shield construction method according to claim 1, characterized in that: In the third step, the synchronous double-liquid grouting pressure is 1-4 Bar when excavating the first 3 / 4 ring length of the second ring.

6. The single cycle pipe wall post-synchronous alternate grouting shield construction method according to claim 1, characterized in that: In the fifth step, the single-liquid grouting pressure is controlled at 4 Bar, and the synchronous double-liquid grouting pressure is controlled at 5-6 Bar.

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