Water stop pile construction technology

Abstract

The invention provides a water stop pile construction process, which relates to the field of constructional engineering, and comprises the following steps: S1, positioning: cleaning a construction site, and determining a pile position; s2, drilling is conducted, specifically, drilling is conducted at the pile position through a drilling machine; s3, an injection pipe is lowered, slurry and gas test injection is conducted on the ground firstly, and after it is checked that all technological parameters meet the design requirements, the injection pipe is lowered to the design depth; s4, slurrying: mixing cement, fly ash, water and other materials according to a certain proportion to prepare slurry; s5, jet lifting is conducted, specifically, in the grouting process, the grouting pipe is slowly lifted, and grout is evenly distributed in the drill hole; s6, recharging is conducted, and static pressure filling grouting is conducted in the jet holes; s7, recording; s8, equipment cleaning: after construction is finished, grouting equipment is cleaned; the method has the advantages of simple construction process, light equipment, high mechanization degree and easiness in operation, and the construction efficiency is effectively improved; and the water stopping effect is good, underground water permeation can be effectively prevented in the construction process, the method is suitable for any soft soil layer, and the reinforcing range can be controlled.

Description

Technical Field

[0001] The invention relates to the field of construction engineering, and in particular to a water stop pile construction process. Background Art

[0002] Waterstop piles are a kind of supporting structure commonly used in civil engineering. They are mainly used to prevent or reduce the continuous waterstop body from flowing into the foundation pit from the side walls and bottom of the foundation pit. They usually form a foundation pit retaining system together with retaining piles and supporting structures. The function of waterstop piles is to consolidate the soil behind the retaining wall and block the exchange of water layers inside and outside the foundation pit, so as to achieve the purpose of waterproofing. Traditional waterstop pile construction processes usually use methods such as cast-in-place piles or mixing piles, but these methods have the problems of great construction difficulty, complex equipment, unsatisfactory waterstop effect and small adaptability. Summary of the invention

[0003] The purpose of the present invention is to provide a water stop pile construction process to solve the technical problems existing in the prior art.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] A water-stop pile construction process includes the following steps: to improve construction efficiency and meet design requirements, before construction, S1 positioning is first performed to clean the construction site, determine the pile position, and put the pile driver in place; to facilitate subsequent grouting or other construction operations, S2 drilling is performed, and a drilling rig is used to drill a hole at the pile position, and the drilling depth should be determined according to design requirements; to inject cement slurry or other water-stopping materials into the ground by high-pressure jetting to achieve a water-stopping effect, S3 lowering the jet pipe is performed, the jet trolley is moved to the hole, slurry and air test jetting is first performed on the ground, and after checking that various process parameters meet the design requirements, the jet pipe is lowered to the designed depth, and after inspection and approval by on-site quality inspection personnel Only then can high-pressure grouting construction be carried out; S4 slurry preparation, mixing cement, fly ash, water and other materials in a certain proportion to prepare slurry; S5 jet lifting, during the grouting process, slowly lift the grouting pipe to make the slurry evenly distributed in the borehole; in order to maintain the stability of the groundwater level and prevent soil consolidation and settlement, S6 backfilling is carried out. After the spraying is completed, static pressure filling grouting is carried out in the spraying hole until the slurry surface no longer sinks, so as to ensure the top elevation of the high-pressure grouting anti-seepage wall after consolidation; S7 records, each process of drilling and high-pressure grouting during construction should be recorded in detail, timely and accurately, and all records must use a unified form as required; S8 equipment cleaning, after the construction is completed, the grouting equipment should be cleaned.

[0006] Furthermore, in S1, the pile diameter is φ600@400. When determining the hole position, the hole position is determined strictly according to the design, and the error is no more than 2 cm, and it is fixed with wooden stakes.

[0007] Furthermore, after the S2 drilling is completed, a technical staff will conduct a quality inspection, and after passing the inspection, the next hole will be moved to drill.

[0008] Furthermore, in S4, P.C42.5R composite silicate cement is used for stirring, the cement is fresh and has no lumps, and the residue passing through a 0.08 mm square hole sieve is ≤5%.

[0009] Furthermore, the slurry in S4 is stirred with a high-speed stirrer. The slurry must be stirred continuously and evenly. The stirring time is not less than 30 seconds, and the stirring time is controlled within 4 hours.

[0010] Furthermore, in S5, when the injection pipe is lowered to the designed depth, slurry that meets the requirements is fed in, and when the injected slurry emerges from the orifice, it is lifted from bottom to top according to the designed lifting method and speed until it reaches the designed final injection elevation.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention uses a small diameter drill hole and jet grouting to form a fixed body 8-10 times larger than the pile hole diameter, which can improve the shear strength of the foundation;

[0013] (ii) The present invention can be used to reinforce the foundation of existing buildings without disturbing the nearby soil, and the construction noise and vibration are low;

[0014] (3) The invention has simple construction process, light equipment, high degree of mechanization, easy operation, and effectively improves construction efficiency;

[0015] (iv) The present invention can effectively prevent groundwater infiltration during the construction process, is applicable to any soft soil layer, and the reinforcement range can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of the present invention; DETAILED DESCRIPTION

[0017] In order to make the content of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. The same parts are represented by the same figure marks. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "inside" and "outside" refer to the directions toward or away from the geometric center of a specific component, respectively.

[0018] like Figure 1 As shown, this embodiment provides a water stop pile construction process, including the following steps:

[0019] S1 positioning, cleaning the construction site, determining the pile position, and putting the pile driver in place, with a pile diameter of φ600@400. When determining the hole position, the hole position should be determined strictly in accordance with the design, with an error of no more than 2cm, and fixed with wooden piles. Fixed piles should be set at the bends of the high-pressure jet grouting axis, and control piles should be set within 5 to 10m of the construction axis. Through accurate positioning, water-stop piles can be placed in areas where water is required to be stopped, forming an effective water-stop barrier to prevent the flow of groundwater. When positioning, the appropriate pile position can be selected according to the geological survey structure to avoid weak address areas or obstacle areas, thereby improving the feasibility and effectiveness of construction.

[0020] S2 drilling, use a drilling rig to drill holes at the pile position, the drilling depth should be determined according to the design requirements, move the drilling rig to the drilling position during construction, align the hole position with a spirit level to grasp the level of the machine, vertical axis vertical, pad the frame, the verticality of the drilling rig meets the accuracy requirements, and drilling can only be started after passing the inspection by the technical staff. If the drilling rig is found to be tilted, stop the machine and level it before drilling; use an alloy drill bit for drilling construction. During the drilling process, if any abnormal situation occurs, find out the cause in time and take corresponding measures. Record the formation changes, particle size, hardness, etc. in detail. After the drilling is completed, the technical staff will conduct a quality inspection. After passing the inspection, move to the next hole; in some areas with poor geological conditions, drilling can help improve the mechanical properties and stability of the soil. For example, drilling can drain water from the soil, reduce the porosity of the soil, and improve the bearing capacity of the soil.

[0021] S3 lowers the jet pipe, moves the jet trolley to the hole, first conducts slurry and air test spraying on the ground, checks that all process parameters meet the design requirements, then lowers the jet pipe to the designed depth, and only after inspection and approval by on-site quality inspection personnel can high-pressure jet grouting construction be carried out. In the process of spraying, if there are special circumstances, such as excessive slurry pressure or nozzle blockage, the jet pipe should be lifted out of the ground for treatment, and then construction can be carried out after treatment; the sprayed water-stopping material can fill the soil voids, improve the density and stability of the soil, help to enhance the soil's anti-seepage ability, and improve the effect of the water-stopping piles. Compared with other water-stopping methods, the lower jet pipe can complete the water-stopping construction quickly and efficiently. It can form a water-stopping curtain in a shorter time, reducing the construction period and cost.

[0022] S4 slurry preparation, cement, fly ash, water and other materials are mixed in a certain proportion to prepare a slurry; the cement is P.C42.5R composite silicate cement, the cement is fresh and has no lumps, and the residue passing through the 0.08mm square hole sieve is ≤5%. The cement must have a manufacturer's product certificate and be inspected and tested according to relevant regulations. The water used for slurry preparation must be clean and pollution-free and meet the requirements for mixing hydraulic concrete; the slurry is stirred according to the designed ratio, the specific gravity of the slurry should be measured at any time during the slurry preparation process, and the material consumption of each hole should be counted after the high-speed grouting of each hole is completed; the slurry is stirred with a high-speed mixer, the slurry is mixed continuously and evenly, the stirring time is not less than 30 seconds, and the stirring time is controlled within 4 hours.

[0023] S5 jet lifting: during the grouting process, the grouting pipe is slowly lifted to make the slurry evenly distributed in the borehole; when the jet pipe is lowered to the designed depth, the slurry that meets the requirements is started to be fed in, and when the injected slurry emerges from the hole, it is lifted from bottom to top according to the designed lifting method and speed until it reaches the designed final jetting elevation.

[0024] S6 backfilling, after the injection is completed, static pressure filling and grouting are carried out in the injection hole until the slurry surface stops sinking to ensure the wall top elevation after the high-pressure injection anti-seepage wall is consolidated. The backfilling slurry is generally filled with static pressure from the adjacent hole high-pressure injection slurry. During the construction of water-stop piles, the surrounding groundwater level may be affected. Through backfilling, the relative stability of the groundwater level is maintained to prevent problems such as ground subsidence and building cracking caused by the drop in groundwater level.

[0025] S7 records, each process of drilling and high-pressure spray grouting during construction should be recorded in detail, timely and accurately. All records must use a unified form as required. The various data and information in the construction process can help monitor the construction quality through recording. By analyzing the records, potential problems can be discovered, and timely measures can be taken to correct them to ensure that the construction quality of water-stop piles meets the requirements; it can also provide a detailed history of the construction process for easy traceability and verification. When problems arise in the later stage or quality inspections are required, the specific circumstances of the construction can be understood by consulting the records, the root causes of the problems can be found, and corresponding solutions can be taken; the content of the records may include the following aspects: 1. Construction date and time, 2. Construction personnel and persons in charge, 3. The use of construction equipment and tools, 4. The type, specifications and quantity of water-stop piles, 5. Various parameters during the construction process, 6. The use of raw materials and quality inspection results, 7. Problems encountered during construction and solutions, 8. Results of quality inspection and acceptance, 9. Visual records such as construction photos and videos, etc.

[0026] S8 cleaning equipment. The residual materials during the construction process may cause corrosion, wear and other damages to the equipment, shortening the service life of the equipment. After the construction is completed, cleaning the grouting equipment can effectively remove these harmful substances and protect the equipment.

[0027] In S5, the technician on duty should check the operation status of each link in real time during the injection process and take the following measures according to the specific situation:

[0028] ① Connect, remove and replace pipes quickly to prevent hole collapse and blockage;

[0029] ② If the spraying is interrupted due to a fault, it should be handled as appropriate: in case of mechanical failure, try to shorten the interruption time and resume grouting as soon as possible; if the interruption time exceeds 1 hour, remedial measures should be taken; when resuming the spraying, the spray pipe should be lowered 0.3m further to ensure the continuity of the condensate.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water stop pile construction process, Features: The following steps are involved: S1 positioning, cleaning the construction site, determining the pile position, and positioning the pile driver; S2 drilling: use a drilling rig to drill holes at the pile position. The drilling depth should be determined according to the design requirements; S3 lowers the jet pipe, moves the jet trolley to the hole, first conducts slurry and air test spraying on the ground, checks that all process parameters meet the design requirements, then lowers the jet pipe to the designed depth. High-pressure jet grouting construction can only be carried out after inspection and approval by on-site quality inspection personnel; S4 slurry preparation, mixing cement, fly ash, water and other materials in a certain proportion to prepare slurry; S5 jet lifting: during the grouting process, the grouting pipe is slowly lifted to make the slurry evenly distributed in the borehole; S6 backfilling: after the injection is completed, static pressure filling and grouting are carried out in the injection hole until the slurry surface no longer sinks, so as to ensure the top elevation of the high-pressure injection anti-seepage wall after consolidation; S7 records: each process of drilling and high-pressure grouting during construction should be recorded in detail, timely and accurately. All records should be recorded in a unified form as required; S8 cleaning equipment, clean the grouting equipment after construction is completed.

2. The water stop pile construction process according to claim 1, Features: In S1, the pile diameter is φ600@400. When determining the hole position, the hole position is determined strictly according to the design layout, and the error is no more than 2cm, and it is fixed with wooden stakes.

3. The water stop pile construction process according to claim 1, Features: After the S2 drilling is completed, the technicians will conduct a quality inspection, and if it is qualified, they will move to the next hole for drilling.

4. The water stop pile construction process according to claim 1, Features: In the S4, P.C42.5R composite silicate cement is used for stirring. The cement is fresh and has no lumps. The residue passing through a 0.08 mm square hole sieve is ≤5%.

5. The water stop pile construction process according to claim 4, Features: The slurry in S4 is stirred with a high-speed stirrer. The slurry must be stirred continuously and evenly. The stirring time is not less than 30 seconds, and the stirring time is controlled within 4 hours.

6. The water stop pile construction process according to claim 1, Features: In S5, when the injection pipe is lowered to the designed depth, the slurry that meets the requirements begins to be fed, and when the injected slurry emerges from the orifice, it is lifted from bottom to top according to the designed lifting method and speed until it reaches the designed final injection elevation.

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