Tunnel advancing type sub-sequence segment top water advance curtain grouting construction process

Abstract

The tunnel advancing type sub-sequence segment top water advance curtain grouting construction process comprises the following steps: construction preparation; measurement and line laying, calibration of hole position, opening of hole pipe segment hole making and installation of hole pipe and matched water stop gate valve, while grouting segment hole making; segment advancing type advance curtain grouting and checking of grouting effect, grouting qualified hole grouting is ended and other grouting holes are made and grouted, and segment advancing type advance curtain grouting is performed again for unqualified grouting; after all grouting holes are completely grouted, the whole grouting effect is checked, and the grouting construction is completed after the qualified detection, and the hole grouting is performed for unqualified checking. The process flow of the application is the same as that of the conventional pure pressure type top water grouting process, but the sequence is divided on the conventional grouting process, the subsequent hole is fully utilized as the effect checking of the front sequence grouting completed hole, and the grouting construction efficiency is accelerated to a certain extent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a tunnel advancing type sequential sectional water top advance curtain grouting construction process. BACKGROUND

[0002] China's karst region is very widely distributed, nearly 340 million square kilometers, is the world's karst region distribution most widely country. With the rapid construction of China's transportation, water conservancy and hydropower and other major infrastructure projects, more and more engineering facilities gradually move to the ground and are built in the karst region. At present, in the aspect of tunnel engineering, China has become one of the countries with the largest scale and most difficult construction in the world, and in many large and deep tunnel construction, there are problems such as slow excavation, difficult support and high maintenance cost in the later period, especially in the karst development zone, so the karst gushing water geological disaster has gradually become a bottleneck problem restricting the scale and development of China's tunnel construction. Karst is one of the common geological disasters in mountain tunnel construction, and through the investigation and analysis of karst disasters in karst areas, it is considered that the karst tunnel without prior safety measures will suffer sudden damage during excavation, which has a greater impact on the stability of the tunnel. When the tunnel is under construction, if there are soft rock, water-rich, filling type cave and other adverse geology in front of the tunnel face, direct excavation is easy to cause geological disasters such as collapse, water and mud inrush, and advanced curtain grouting is a key problem to ensure the safety of tunnel construction. The current advanced curtain grouting construction has problems such as high grouting technical requirements, complex construction process, long construction period and high cost. SUMMARY

[0003] In view of the above problems, the tunnel advancing type sequential sectional water top advanced curtain grouting construction process is provided. To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0004] The tunnel advancing type sequential sectional water top advanced curtain grouting construction process comprises the following steps:

[0005] S1, construction preparation;

[0006] S2, measurement and line laying, calibration of hole position, opening of hole pipe section, installation of hole pipe and supporting water stop gate valve, and hole drilling in grouting section;

[0007] S3, sectional advancing type advanced curtain grouting and inspection of grouting effect, grouting qualified to end the grouting of the hole and grouting of other grouting holes, and sectional advancing type advanced curtain grouting again for unqualified grouting;

[0008] S4, after all grouting holes are completely grouted, the overall grouting effect is checked, and the grouting construction is completed if the detection is qualified, and supplementary grouting is performed if the detection is unqualified.

[0009] Preferably, a geological drilling machine is used for hole drilling.

[0010] Preferably, the slurry is prepared before grouting, and the slurry is prepared by using a low-speed stirrer.

[0011] Preferably, a double-cylinder double-liquid grouting pump is used for grouting.

[0012] Preferably, the orifice pipe end is connected to a "T"-shaped extension pipe through a flange, and then connected to a high-temperature hot water anti-burst device matched with a drill pipe and customized, to prevent high-temperature hot water from gushing in the hole during the hole forming process. After the installation and embedding of the orifice pipe are completed, before the hole forming of the grouting section is prepared, the drill pipe is first passed through the anti-burst device, then the drill bit is installed, the drill pipe is then passed through the extension pipe and the orifice pipe, and finally the hole forming operation is performed after the bolt and flange connection are firmly connected.

[0013] Preferably, an automatic pneumatic switch is installed at the outlet end of the drain pipe at the lower end of the "T"-shaped extension pipe. The pneumatic switch is connected to a pneumatic pump through a dedicated inlet and outlet air pipe, and can realize the opening and closing operation of the pneumatic switch at a long distance. Thus, the risk of scalding caused by the close or opening of the gate valve by human close contact can be effectively avoided. Preferably, a pressure relief device is connected to the slurry inlet channel reserved on the orifice pipe through a thread port, so that the pressure can be quickly released when the pressure increases sharply or other abnormal conditions occur during the grouting process, to ensure the safety of the grouting operation.

[0014] The above technical solution has the following advantages or beneficial effects:

[0015] The process flow is the same as the conventional pure pressure type water grouting process, but the process is divided into sequences on the conventional grouting process, and the effect of the subsequent hole is fully utilized as the inspection of the completed hole in the previous sequence, so that the grouting construction efficiency is accelerated to a certain extent.

[0016] According to the sectional standard of the water yield in the hole forming process and the drainage demand of the special drainage pipeline set in the hole in advance, the length of each sequence hole grouting section can be dynamically adjusted, and the operation is flexible and the grouting and water plugging construction quality is more easily controlled.

[0017] According to the water outlet position detected by the various types of geophysical prospecting data, deepening blast hole and advanced horizontal drilling data, the additional supplementary grouting section is more targeted for the treatment of high-temperature underground water, and the safety of the subsequent tunnel excavation construction operation is more easily ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application and its features, shapes and advantages will become more apparent by reading the following detailed description of non-limiting embodiments, with reference to the accompanying drawings. The same reference signs indicate the same parts throughout the drawings. The drawings are not necessarily drawn to scale, and the emphasis is on illustrating the main idea of the present application.

[0019] Fig. 1 is a process flow diagram of the present application;

[0020] Fig. 2 This is a cross-sectional layout diagram of the grouting openings. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but these are not intended to limit the scope of the invention.

[0022] Example 1

[0023] like Figs. 1-2 As shown, the tunnel advance-type segmented top-water advanced curtain grouting construction process provided in Embodiment 1 of the present invention includes the following steps:

[0024] S1. Construction preparation;

[0025] S2. Surveying and setting out, marking the hole positions, drilling the borehole section and installing the borehole pipe and matching water-stop valve, and drilling the grouting section at the same time. A geological drilling rig is used for drilling. The drilling efficiency of the geological drilling rig is that, under the condition that there is no water inrush during the drilling process, the average time required to drill a 30m hole is 2.5h; if there is water inrush, the average time required to drill a 30m hole is 3.5h to 4h.

[0026] S3. Perform segmented, forward-moving, advanced curtain grouting and check the grouting effect. If the grouting is qualified, the grouting of that hole is ended, and the drilling and grouting of other grouting holes are carried out. If the grouting is not qualified, segmented, forward-moving, advanced curtain grouting is performed again. Before grouting, slurry preparation is carried out using a low-speed mixer with a stirring speed of 200 r / min. During grouting, a double-cylinder, double-liquid grouting pump is used, with a rated grouting flow rate of 50 L / min for single-liquid grouting and 100 L / min for double-liquid grouting, and a rated maximum grouting pressure of 16 MPa.

[0027] S4. After all grouting holes have been filled, check the overall grouting effect. If the test is qualified, the grouting construction is completed. If the test is not qualified, fill in the missing holes with additional grout.

[0028] The orifice pipe end is connected to a "T"-shaped extension pipe via a flange, and then to a custom-made high-temperature hot water anti-outburst device that matches the drill pipe, to prevent high-temperature hot water from gushing out and injuring people during the drilling process. After the orifice pipe is installed and buried, before drilling the grouting section, the drill pipe is first passed through the anti-outburst device, then the drill bit is installed, the drill pipe is then passed through the extension pipe and the orifice pipe, and finally the connection is secured with bolts and flanges before drilling operations begin.

[0029] Preferably, the end of the drain pipe installed at the lower end of the "T" type extension pipe is equipped with an automatic pneumatic switch, which is connected to the pneumatic pump through a dedicated inlet and outlet pipe, so that the opening and closing of the pneumatic switch can be remotely controlled, thereby effectively avoiding the risk of scalding caused by human contact with the gate valve during opening or closing.

[0030] In the present embodiment:

[0031] The grouting segmentation standards are as follows:

[0032] (1) The drilling water yield is not more than 5 m 3 / h, and the grouting is performed after drilling to the final hole;

[0033] (2) The drilling water yield is 5-10 m 3 / h, and the segmentation distance is 10-15 m;

[0034] (3) The drilling water yield is 10-30 m 3 / h, and the segmentation distance is 5-10 m;

[0035] (4) The drilling water yield is greater than 30 m 3 / h, and the drilling is stopped and grouting is performed in time.

[0036] The single-hole grouting completion standards are as follows:

[0037] The single-hole grouting completion standards: The grouting completion standard adopts a constant pressure control standard, and the final grouting pressure is 6 MPa, which is maintained for 5-10 min, and then the grouting of the hole is completed.

[0038] The grouting effect inspection standards are as follows:

[0039] The grouting effect is inspected by setting inspection holes: after the completion of the grouting of all the holes in a cycle, inspection holes are set near the main water outlets according to the water inrush of each hole during the hole forming process, and the water inrush of the holes is measured. The inspection holes should meet the requirement that the water yield is not more than 2 L / m·min, and the grouting is completed in the cycle, otherwise, the holes should be supplemented and grouted. The number of inspection holes is 5% of the total grouting holes, and is not less than 5.

[0040] The designed grouting materials and their proportions are as follows:

[0041] The grouting material proportions are as follows: the improved high-temperature oil well cement special grouting material is mainly used (the temperature range is 50-370℃), the oil well cement-water glass double-liquid slurry, the P.O42.5 ordinary portland cement-water glass double-liquid slurry, and the P.O42.5 ordinary portland cement single-liquid slurry are used as supplements, the water glass Baumé degree is 40 Be', and the volume ratio of the mixing amount is 1:1.

[0042] The slurry ratio is as follows:

[0043] ① Oil well cement single slurry: W:C = 0.6:1-0.8:1;

[0044] ② Oil well cement double slurry: W:C = 0.8:1-1:1, C:S = 1:1;

[0045] ③ Ordinary cement-sodium silicate double slurry: W:C = 0.8:1-1:1, C:S = 1:1;

[0046] ④ Ordinary cement single slurry: W:C = 0.6:1-0.8:1.

[0047] The hole forming construction method of the orifice section is as follows:

[0048] According to the measured loft calibration hole position, according to the design drawing each sequence hole external angle requirement, determine the drilling external angle, the grouting hole hole forming construction adopts the Baoye 805 type drilling machine to construct; the orifice section opening hole diameter is 130mm, the hole forming depth of each sequence hole orifice section is unified as 2m.

[0049] The processing and manufacturing and installation method of the orifice pipe is as follows:

[0050] The orifice pipe adopts Φ108mm, wall thickness 4.5mm hot-rolled seamless steel pipe to be concentrated in the processing factory, single length 2m, the orifice pipe end is connected with the mechanical gate valve matched with the pipe diameter through the flange, after the hole forming of the orifice section 2m range is completed, the hole outside the hole orifice pipe is wound with the rope into a spindle type, the orifice pipe is knocked into the orifice section bedrock which has been formed by artificial or mechanical, the orifice pipe is buried into the bedrock depth of 2m, and the gap between the hole wall and the pipe wall is anchored with the cement-based anchoring agent, to ensure that the orifice pipe is installed firmly and does not leak water. At the same time, in order to ensure the stability and firmness of the orifice pipe under pressure during the grouting hole closing process, 4 medicine roll anchor rods are welded with the orifice pipe for each orifice pipe; the medicine roll anchor rod diameter is Φ22mm, single length 2.5m.

[0051] The hole forming construction method of the grouting section is as follows:

[0052] After the orifice pipe installation is completed and reaches a certain strength, the hole forming construction of the grouting section is carried out by using the drill rod through the orifice pipe, the hole forming diameter of the grouting section is 90mm, and the hole forming method of the grouting section is the same as that of the orifice section.

[0053] The slurry preparation method is as follows:

[0054] The slurry preparation station is set at a position about 30m away from the operation face, and the feeding and mechanical slurry preparation are carried out by artificial cooperation with fixed hanger.

[0055] The grouting construction sequence is as follows:

[0056] The grouting sequence is constructed according to the principle of grouting from outside to inside, from bottom to top and interval hole jumping. The specific construction step sequence is as follows: the first step is to construct B sequence holes numbered B1, B3, B5, B7, B9, B12, B14, B16, B18, a total of 9 holes; the second step is to construct B sequence holes numbered B2, B4, B6, B8, B10, B11, B13, B15, B17, B19, a total of 10 holes; the third step is to construct C sequence holes numbered C1, C3, C5, C7, C9, C11, a total of 6 holes; the fourth step is to construct C sequence holes numbered C2, C4, C6, C8, C10, C12, a total of 6 holes; the fifth step is to construct A sequence holes according to the principle of hole construction, and to select partial grouting holes for water plugging and grouting according to the water outlet position and water yield of the B and C sequence holes in the above first to fourth steps; the sixth step is to construct E sequence holes according to the principle of hole construction, and to select partial grouting holes for water plugging and grouting according to the water outlet position and water yield of the B, C and A sequence holes in the above first to fifth steps; the seventh step is to construct D sequence holes numbered D1, D2, D3, D4, D5, D6, a total of 6 holes.

[0057] The grouting construction method is as follows:

[0058] When the water yield of the drill hole reaches the requirement of the sectional grouting standard, the water stop valve at the end of the hole pipe is closed in time, and then the mixer, grouting pipe and grouting plug ball valve are connected through the socket type buckle, and then the pure pressure water plugging grouting construction is carried out. When the grouting of this section reaches the design end standard, the grouting plug ball valve is closed for more than 12 hours. Then the hole is drilled and re-grouted through the hole pipe, and the cycle continues until the design depth is reached.

[0059] Summary of the construction process:

[0060] (1) Grouting material: The grouting materials used in the process of the tunnel extremely high temperature hot water section cycle grouting and water plugging construction include oil well cement, ordinary portland cement, water glass and admixture. During the on-site construction process, 11 kinds of grouting tests under different mixing conditions were carried out using the above 4 kinds of grouting materials. The effect analysis was carried out through the quantified indicators such as the length of the grouting hole and the water yield. The grouting effect of the single liquid slurry of ordinary cement combined with the double liquid slurry of ordinary cement is the best.

[0061] (2) Grouting mixing ratio: The water-cement ratio of the single liquid slurry of ordinary cement is 1.5:1:1 and 0.6:1 respectively; the water-cement ratio of the double liquid slurry of ordinary cement is 0.8:1 and 0.6:1 respectively, and the water glass content is 15% (mass ratio).

[0062] (3) Grouting ratio and material: The grouting slurry is made of ordinary cement single slurry. The grouting water-cement ratio is determined according to the water yield in the hole. When the water yield is less than 10 m 3 / h, the grouting water-cement ratio is 1.5:1; when the water yield is more than 10 m 3 / h, the grouting water-cement ratio is 1:1. When the grouting pressure and injection rate do not change obviously after the single slurry is used for 30 min, the grouting can be directly made by using ordinary cement double slurry with a ratio of 0.6:1 or the thick slurry is used to continue the grouting by the single slurry.

[0063] (4) Change of slurry: When the single-hole grouting is made by using multi-stage water-cement ratio single slurry, the slurry change principle is from dilute to thick. When the grouting pressure remains unchanged and the injection rate continuously decreases, or when the injection rate remains unchanged and the pressure continuously increases, the water-cement ratio is not changed. When the injection amount of a certain stage single slurry reaches 3000 L or more and the grouting pressure and injection rate do not change or change is not obvious, the grouting is directly made by using ordinary cement double slurry with a ratio of 0.6:1. When the injection rate is appropriately reduced but remains around a constant value during the grouting by using single slurry, the grouting can be made by using ordinary cement double slurry with a ratio of 0.8:1. When the grouting pressure or injection rate changes obviously, the water-cement ratio is not changed. When the grouting pressure and injection rate do not change or change is not obvious or the total injection amount is reached, the grouting is made by using ordinary cement double slurry with a ratio of 0.6:1.

[0064] (5) Treatment of slurry leakage: When the slurry leakage occurs during the grouting, the gate valve on the hole orifice pipe should be closed in time. After the grouting of the grouting hole is completed, the slurry leakage hole is swept, washed, and grouted. If the injection rate of the grouting hole is not large and the slurry leakage hole has the grouting conditions, the grouting can be made by using one pump and one hole in parallel.

[0065] (6) Treatment of slurry leakage: During the grouting, if the slurry leakage is found, the methods such as caulking, surface plugging, low pressure, thick slurry, flow limiting, quantity limiting, intermittent, setting, hole sweeping, and re-grouting can be used for treatment.

[0066] (7) Treatment of hole section with large amount of consumed slurry: Firstly, the grouting pressure is reduced, the thick slurry is used, and the injection rate is reduced and limited. When the consumed slurry amount of the hole section exceeds 0.6 t / m of the designed average slurry absorption amount, the grouting pressure does not rise, and there is no slurry leakage, the grouting should be stopped, the hole is swept after setting for 24 h, and then the grouting is re-made. If the injection rate gradually decreases or the grouting pressure gradually rises during the re-grouting, the grouting is normally made until the end. If the injection rate is greatly different from that before setting and the consumed slurry amount is very small during the re-grouting, the hole section should be swept and then grouted.

[0067] (8) Regardless of the measures used for treatment, the hole section should be swept and re-grouted finally. The re-grouting end hole conditions should meet the designed end conditions.

[0068] (9) Other technical aspects requirements: ① When the water yield in the hole is greater than 20 m 3 / h, first adopt two parallel grouting pumps to increase the flow rate. ② When intermittent grouting measures are taken, the intermittent time should not exceed the time when the slurry loses fluidity. ③ The length of the pipeline between the mixer and the grouting hole should be 15 m. ④ In order to ensure the accuracy and reliability of the water pressure monitoring data in the hole, the pressure monitoring meter should be installed on the Φ40 grouting channel reserved on the hole pipe. ⑤ If short-term non-continuous injection occurs during grouting, continuous water injection should be used to prevent grouting pump or slurry pipeline from being blocked.

[0069] (10) Grouting work must be continuous, if interrupted for any reason, the following principles should be followed: ① Try to shorten the interruption time and resume grouting as soon as possible; if there is no condition to resume grouting in a short time, the borehole should be flushed immediately and then grouting should be resumed. If it cannot be flushed or flushing is ineffective, the hole should be swept and then grouting should be resumed. ② When resuming grouting, cement slurry with the same concentration as before should be used for grouting. If the injection rate is similar to that before interruption, the same concentration of cement slurry as before can be used for continuous grouting; if the injection rate is much lower than before, the slurry should be gradually thickened for continuous grouting; if the injection rate is much lower than before and stops absorbing slurry in a short time, remedial measures should be taken, such as gradually thickening the cement slurry. ③ After resuming grouting, if the amount of slurry absorbed is much less than before and stops absorbing slurry in a very short time, the hole section is considered unqualified.

[0070] Those skilled in the art should understand that those skilled in the art can realize variations in combination with the prior art and the above embodiments, which are not described here. Such variations do not affect the essential content of the present application, which are not described here.

[0071] The above describes the preferred embodiments of the present application. It should be understood that the present application is not limited to the above specific embodiments, and the equipment and structures not fully described should be understood as implemented in the ordinary way in the art; any person skilled in the art can make many possible changes and modifications, or modify equivalent embodiments without departing from the technical solution of the present application, which does not affect the essential content of the present application. Therefore, any simple modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present application without departing from the technical solution of the present application, all still belong to the scope of protection of the technical solution of the present application.

Claims

1. A tunnel advancing type sub-sequence sectional top water pre-curtain grouting construction process, characterized in that, Includes the following steps: S1. Construction preparation; S2. Measure and lay out the lines, mark the hole positions, drill holes for the orifice pipe section and install the orifice pipe and matching water-stop valve, and drill holes in the grouting section at the same time. S3. Perform segmented advance curtain grouting and check the grouting effect. If the grouting is qualified, the grouting of the hole is ended and the drilling and grouting of other grouting holes are carried out. If the grouting is not qualified, the segmented advance curtain grouting is performed again. S4. After all grouting holes have been filled, check the overall grouting effect. If the test is qualified, the grouting construction is completed. If the test is not qualified, the holes are filled and grouting is carried out. The grouting segmentation standards are as follows: (1) The drilling water yield is not more than 5m 3 / h, and grouting after drilling to the final hole; (2) The drilling water yield is 5-10 m 3 / h, and the segmented distance is 10-15 m; (3) The drilling water yield is 10-30 m 3 / h, and the segmented distance is 5-10 m; (4) The drilling water yield is greater than 30 m 3 / h, stop drilling and carry out grouting in time. The criteria for completing single-hole grouting are as follows: Single-hole grouting completion standard: The grouting completion standard adopts the constant pressure control standard. The final grouting pressure is 6 MPa and maintained for 5-10 minutes, which means the construction of the grouting hole is completed. The grouting effect inspection standards are as follows: The grouting and water-blocking effect is checked by setting inspection holes: After all the grouting holes are grouted in each cycle, inspection holes are set near the main water outlets according to the water inrush situation of each hole during the hole-making process. The water inrush volume in the hole is measured. The grouting is considered qualified and the cycle of grouting construction is ended if the water outflow of the inspection hole does not exceed 2L / m·min. Otherwise, the hole is supplemented for grouting. The orifice pipe end is connected to a "T"-shaped extension pipe via a flange, and then connected to a customized high-temperature hot water anti-outburst device that matches the drill rod. After the orifice pipe is installed and buried, before drilling the grouting section, the drill rod is first passed through the anti-outburst device, then the drill bit is installed, the drill rod is passed through the extension pipe and the orifice pipe again, and finally the hole is drilled after being firmly connected with bolts and flanges. An automatic pneumatic switch is installed at the drain outlet of the "T"-shaped extended pipe. The pneumatic switch is connected to a pneumatic pump through a dedicated inlet and outlet air pipe, enabling remote opening and closing of the pneumatic switch. This avoids the risk of burns caused by close contact with the valve. A pressure relief device is connected to the grout inlet channel on the orifice pipe via a threaded connection, which can quickly relieve pressure in case of a sudden increase in pressure or other abnormal situations during grouting, ensuring the safety of grouting operations.

2. The tunneling sectionalized pre-augering and pre-curtaining grouting construction process as claimed in claim 1, wherein: A geological drilling rig was used for drilling.

3. The tunneling sectionalizing and segmenting top water pre-veiling curtain grouting construction process according to claim 1, characterized in that: Before grouting, slurry preparation is carried out using a low-speed mixer.

4. The tunneling sectionalizing and segmenting top water pre-veiling curtain grouting construction process according to claim 1, characterized in that: A dual-cylinder, dual-liquid grouting pump is used during grouting.

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