Construction method of underground continuous wall system

Abstract

The present invention relates to a construction method of an underground continuous wall system, comprising the steps of: using an excavator to dig a trench along the guide wall excavation positioning line; setting a guide wall bracket, a guide wall template and a concrete delivery pipe, removing the guide wall template after pouring the guide wall and setting an internal support; using a rotary drilling rig to lead a hole, a slotting machine to grab the upper soil, and a slot milling machine to mill the rock layer; processing the steel cage on a steel cage processing platform; inserting the steel cage and pouring concrete; after completing the cutting along the unit block cutting hole, hoisting the unit block and using a steel wedge and a sleeve. The beneficial effects of the present invention are: positioning the guide wall excavation line through a gantry column, with a higher degree of accuracy; the "L"-shaped guide wall has the functions of locking, slotting guidance, storing mud stabilizing liquid, maintaining the stability of the upper soil and preventing soil collapse, slot segment segment positioning and bearing temporary construction loads, which can significantly improve the accuracy of slotting; the amount of hole opening is small, and the stability of the underground continuous wall is significantly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation pit enclosure construction, and in particular relates to a construction method of an underground continuous wall system. Background Art

[0002] With the development and utilization of urban underground space, the construction of underground civil air defense projects, underground garages, and urban infrastructure is increasing. During the construction of underground foundation pits, it is necessary to protect surrounding buildings and municipal facilities to ensure the normal and safe use of buildings and municipal facilities. For this reason, proper and effective support measures need to be adopted. Underground continuous walls are widely used in urban underground space projects because of their small footprint, strong environmental adaptability, high overall stiffness, and good water and soil retaining properties.

[0003] At present, the traditional underground continuous wall construction technology has the problems of difficult trenching construction, difficult to control the trenching quality in soft soil, easy deformation and tilting of the platform during the processing and hoisting of the steel cage, which affects the entry of the steel cage into the trench and the opening of the underground continuous wall and the sealing of the end holes, posing a threat to the project. At the same time, affected by my country's urbanization process, the density of urban buildings is increasing, the underground space environment is complex, and the requirements for surrounding environmental protection for underground construction have been significantly increased. However, the traditional underground continuous wall construction technology has a complex construction process and has many difficulties that are easy to cause foundation pit deformation and water seepage damage. It is difficult to meet the current protection requirements of urban buildings and existing underground buildings (structures), posing a threat to project safety.

[0004] Therefore, in order to solve the common problems in the construction process of underground continuous walls, there is an urgent need for an underground continuous wall construction technology that is quick and simple to construct, safe and effective, fully functional and low-cost, in view of the current situation of projects where the above problems occur frequently, the process is complex, the construction cost is high and the construction time is long. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a construction method for an underground continuous wall construction system.

[0006] The construction method of the underground continuous wall system comprises the following steps:

[0007] Step 1: The gantry column is arranged along the center line of the underground continuous wall, and the guide wall excavation positioning line is arranged along the fine line arranged on the gantry column; a trench is excavated along the guide wall excavation positioning line by using an excavator;

[0008] Step 2: Set the guide wall support, guide wall formwork and concrete delivery pipe in the groove, remove the guide wall formwork after pouring the guide wall and set the inner support;

[0009] Step 3: Use a high-power rotary drilling rig to drill holes, a slotting machine to grab the upper soil, and a slot milling machine to mill the rock layer;

[0010] Step 4: monitor whether the steel cage processing platform is level by using a strain gauge and a signal acquisition instrument, and adjust the levelness by using the hydraulic jack; process the steel cage on the steel cage processing platform;

[0011] Step 5: Install a wall brush blade on the slotting machine to clean the slot wall; put in the steel cage and pour concrete;

[0012] Step 6: Align the bottom of the H-shaped steel with the bottom elevation of the excavated trench; fix the grout-stopping iron sheets on both sides of the steel cage; backfill the soil bags at the joints of the H-shaped steel;

[0013] Step seven, set up a retaining wall inside the underground continuous wall and install steel sections for drilling on the retaining wall; after cutting holes along the unit blocks, lift out the unit blocks and use steel wedges and sleeves to close the holes.

[0014] Preferably, in step one, the thin wire is tied to the gantry column before the excavator is used for construction, and manual excavation should be used to dig to the bottom of the underground pipeline, and a rectangular box should be added outside the underground pipeline.

[0015] Preferably, in the step 2, a guide wall bracket, a guide wall formwork and a concrete delivery pipe are arranged in the groove, and the guide wall concrete is poured symmetrically. After the guide wall concrete strength reaches % of the design strength, the guide wall formwork is removed; after the guide wall formwork is removed, a safety mesh is laid on the top of the guide wall, and internal supports are arranged, and the internal supports include transverse internal supports, longitudinal internal supports and adjustable brackets; several transverse internal supports are arranged at different heights of the guide wall, and the transverse internal supports at different heights are connected and reinforced by longitudinal internal supports, and the bottom of the transverse internal supports are also reinforced and supported by adjustable brackets.

[0016] Preferably, in step four: the strain gauge is installed on the bottom surface of the steel cage processing platform, and the hydraulic jack is also arranged on the bottom surface of the steel cage processing platform; the strain gauge is connected to a signal acquisition instrument through a wire, and the strain gauge and the hydraulic jack are respectively arranged at different positions on the bottom surface of the steel cage processing platform.

[0017] Preferably, in step four: the steel cage includes a steel cage body, a "J"-shaped reinforcement rib, an X-shaped reinforcement rib and a W-shaped reinforcement rib; the X-shaped reinforcement rib is arranged in the transverse direction of the steel cage body, and the W-shaped reinforcement rib is arranged in the longitudinal direction of the steel cage body; lifting rings are provided at the X-shaped reinforcement rib and the W-shaped reinforcement rib; all lifting points of the upper frame of the steel cage are provided with "J"-shaped reinforcement ribs.

[0018] Preferably, in step six: insert the H-shaped steel into the soil to a depth of 50 cm; after the concrete pouring is completed, remove the earthfill bags.

[0019] Preferably, in step seven: the drilling steel is installed on the retaining wall; the retaining wall is divided into several unit blocks according to the cutting requirements, and the unit block cutting holes are evenly distributed at the four corners of each unit block; a casing pre-buried hole is arranged in the center of each unit block; each unit block is also provided with a unit block lifting ring; a steel wedge is fixed in each hole formed after the unit block is cut, and a sleeve is fixed in the center of the steel wedge.

[0020] An underground continuous wall system obtained by any of the above methods.

[0021] The beneficial effects of the present invention are:

[0022] 1) The excavation positioning system adopted in the present invention positions the guide wall excavation line through the gantry column. Compared with the traditional technology, this technology has a higher positioning accuracy.

[0023] 2) The rectangular box used in the present invention can prevent damage to underground pipelines in the excavation area during the trenching process of the excavator.

[0024] 3) The guide wall used in the present invention is L-shaped and has the functions of locking, trenching guidance, storing mud stabilizing liquid, maintaining the stability of the upper soil and preventing soil collapse, positioning the trench sections and bearing temporary construction loads, etc., which can significantly improve the trenching accuracy and promote the smooth trenching of the continuous wall.

[0025] 4) The present invention adopts a combined trenching technology of rotary-grabbing-milling, which combines the advantages of rotary drilling rigs, trenching machines and trenching machines. Compared with the existing technology, it significantly improves the efficiency of trenching construction and reduces construction costs. After the trenching machine is equipped with a brushing blade, it can also be used to brush the trench wall, so that the soil on the trench wall is completely cleaned, avoiding the influence of the soil on the construction of the underground continuous wall.

[0026] 5) The steel cage precise control and adjustment processing system adopted in the present invention can monitor the processing platform and adjust the processing platform according to the monitoring results to avoid deformation of the steel cage caused by deformation and tilt of the processing platform.

[0027] 6) The present invention adopts X-shaped reinforcement ribs and W-shaped reinforcement ribs to prevent the steel cage from being excessively deformed during the hoisting process; a lifting ring is arranged near the reinforcement ribs for hoisting the steel cage; and a "J"-shaped reinforcement rib is required to be arranged on all lifting points arranged on the upper frame of the steel cage to avoid excessive deformation of the lifting points of the steel cage;

[0028] 7) The end hole backfill system adopted by the present invention can block the flow of concrete and mortar along the bottom of the end steel plate; at the same time, the additional stop iron sheets fixed on both sides of the steel cage can block the mortar flow along the outer side of the H-shaped steel; the use of earth filling bags instead of the original technical measures of placing joint boxes can ensure that the inside and outside sides are evenly alternated and the H-shaped steel joint is backfilled densely. This technical measure not only ensures the anti-seepage requirements of the H-shaped steel joint, but also eliminates the risks of placing joint boxes.

[0029] 8) The underground continuous wall opening system adopted by the present invention has a small amount of opening work, and the stability of the underground continuous wall is significantly improved. Compared with traditional technologies, it has good safety and economy, and has high construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the underground continuous wall construction flow chart;

[0031] Figure 2 Arrange a top view of the gantry posts;

[0032] Figure 3 Top view of excavation for embedded groove of guide wall;

[0033] Figure 4 This is a top view of the excavation of the embedded groove for the guide wall;

[0034] Figure 5 This is the section drawing of casting the guide wall;

[0035] Figure 6 This is the cross-section view of the guide wall after pouring;

[0036] Figure 7 This is a front view of a high-power rotary drilling rig drilling hole;

[0037] Figure 8 This is the front view of the trenching machine construction;

[0038] Fig. 9 This is the front view of the slot milling machine construction;

[0039] Fig.10 Top view of the machining system for precise control and adjustment of the reinforcement cage;

[0040] Fig.11 Process the top view of the steel cage;

[0041] Fig.12 Processing side view for steel cage

[0042] Fig.13 Process the front view of the steel cage;

[0043] Fig.14 This is a cross-sectional view of the groove wall brush;

[0044] Fig.15 This is the cross-section of the reinforcement cage below;

[0045] Fig.16 Filling the trough with earthbags and placing the conduit cross-section;

[0046] Fig.17 This is the cross-section view after concrete pouring;

[0047] Fig.18 This is a cross-section diagram of the underground continuous wall opening system;

[0048] Fig.19 It is the side view of the underground continuous wall opening system;

[0049] Fig. 20 Side view of the underground continuous wall after the hole is opened and reinforced.

[0050] Among them: excavation positioning system 1, gantry column 1-1, thin line 1-2, underground continuous wall center line 1-3, guide wall excavation positioning line 1-4, excavator 2, rectangular box 3, underground pipeline 4, guide wall construction system 5, concrete mixer 5-1, concrete delivery pipe 5-2, guide wall bracket 5-3, guide wall template 5-4, guide wall 5-5, horizontal inner support 5-6, longitudinal inner support 5-7, adjustable bracket 5-8, high-power rotary drilling rig 6, slotting machine 7, slot milling machine 8, steel cage precise control adjustment processing system 9, signal acquisition instrument 9-1, strain gauge 9-2, hydraulic jack 9-3, Rebar cage processing platform 10, rebar cage 11, lifting ring 11-1, rebar cage body 11-2, “I”-shaped reinforced body 11-3, X-shaped reinforced body 11-4, W-shaped reinforced body 11-5, wall brush blade 12, end hole backfill system 13, grouting iron sheet 13-1, excavated trench section 13-2, conduit 13-4, earthfill bag 13-5, underground continuous wall 14, underground continuous wall opening system 15, retaining wall 15-1, steel section for drilling 15-2, unit block cutting hole 15-3, casing embedded hole 15-4, unit block lifting ring 15-5, steel wedge 15-6, sleeve 15-7. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0052] Embodiment 1

[0053] As an example, Figure 1 As shown, a construction method of an underground continuous wall system comprises the following steps:

[0054] Step 1, the gantry column 1-1 is arranged along the center line 1-3 of the underground continuous wall, and the guide wall excavation positioning line 1-4 is arranged along the fine line 1-2 arranged on the gantry column 1-1; a trench is excavated along the guide wall excavation positioning line 1-4 using an excavator 2; when the excavator 2 digs to the bottom of the underground pipeline 4, a rectangular box 3 is added around the underground pipeline 4 to avoid damage to the underground pipeline 4.

[0055] Step 2: According to the design drawings, set the guide wall support 5-3, the guide wall formwork 5-4 and the concrete delivery pipe 5-2 in the groove to pour the guide wall concrete; after the guide wall 5-5 reaches the design strength, remove the guide wall formwork 5-4 and set up the transverse inner support 5-6, the longitudinal inner support 5-7 and the adjustable support to improve the support strength and rigidity in the groove; the concrete of the guide wall 5-5 must be poured symmetrically, and the guide wall formwork 5-4 can be removed only after the strength reaches 80% of the design strength; after removing the guide wall formwork 5-4, lay a safety mesh on the top of the guide wall to ensure construction safety.

[0056] Step three, using the drilling-digging-milling combination technology, using a high-power rotary drilling rig 6 to drill holes, a slotting machine 7 to grab the upper soil, and a slot milling machine 8 to mill the rock layer; monitor whether the steel cage processing platform 10 is level through the strain gauge 9-2 and the signal acquisition instrument 9-1. If there is local deformation, use the hydraulic jack 9-3 to make adjustments.

[0057] Step 4: Complete the processing of the steel cage 11 on the steel cage processing platform 10.

[0058] Step 5: Use the trenching machine 7 with an additional brushing blade 12 to brush the trench wall to clean the soil; place the steel cage 11 into the trench and complete the concrete pouring.

[0059] Step six, extend the bottom of the H-shaped steel 13-3 to the bottom elevation of the excavated trench section 13-2 and insert it into the soil by 50 cm to block the concrete and mortar from flowing around the bottom of the head steel plate; fix the mortar-stopping iron sheet 13-1 on both sides of the steel cage 11 to block the mortar from flowing around the outside of the H-shaped steel 13-3; backfill the earthbag 13-5 at the joint of the H-shaped steel 13-3, and remove the earthbag 13-5 after the concrete pouring is completed.

[0060] Step seven, set a retaining wall 15-1 on the inner side of the underground continuous wall 14 and install drilling steel on the retaining wall 15-1, and install a unit block lifting ring 15-5 on each concrete block before drilling; after the cutting hole 15-3 along the unit block is completed, lift out the unit block and use the steel wedge 15-6 and the sleeve 15-7 to close the hole.

[0061] Embodiment 2

[0062] As another embodiment, the underground continuous wall construction system obtained in the first embodiment is as follows: Figures 2 to 20 As shown, it includes: an excavation positioning system 1, a guide wall construction system 5, a steel cage precise control adjustment processing system 9, an end hole backfilling system 13 and an underground continuous wall opening system 15;

[0063] The excavation positioning system 1 includes a gantry column 1-1 and a thin wire 1-2; the gantry column 1-1 is arranged along the axis 1-3 of the underground continuous wall, and the thin wire 1-2 is tied to the gantry column 1-1; a guide wall excavation positioning line 1-4 is arranged according to the thin wire 1-2; the central axis of the excavator 2 is consistent with the axis 1-4 of the underground continuous wall, and the soil is excavated along the direction of the guide wall excavation positioning line 1-4.

[0064] A high-power rotary drilling rig 6 is used to drill holes, a slotting machine 7 is used to grab the upper soil, and a slot milling machine 8 is used to mill the rock layer to improve the slotting efficiency. A wall brushing blade 12 is fixed to the bucket of the high-power slotting machine 7; the bucket of the high-power slotting machine 7 is lifted up and down to achieve slot wall brushing.

[0065] The guide wall construction system 5 includes a concrete mixer 5-1, a guide wall bracket 5-3 and a guide wall formwork 5-4; the guide wall bracket 5-3 is arranged in the soil trough where the guide wall is to be cast, and the guide wall formwork 5-4 is symmetrically arranged on both sides of the soil trough where the guide wall is to be cast about the underground continuous wall axis 1-4; the concrete mixer 5-1 pours concrete into the soil trough through a concrete delivery pipe 5-2, and finally casts and forms a guide wall 5-5; a transverse inner support 5-6 is arranged in the center of the guide wall 5-5 to prevent the guide wall 5-5 from overturning; the transverse inner supports 5-6 of different heights are connected and reinforced by longitudinal inner supports 5-7, and the inner supports are reinforced by adjustable brackets 5-8.

[0066] The steel cage precision control and adjustment processing system 9 includes a strain gauge 9-2, a hydraulic jack 9-3 and a steel cage processing platform 10; the strain gauge 9-2 is installed on the bottom surface of the steel cage processing platform 10 and is connected to the signal acquisition instrument 9-1 through a wire to monitor the deformation of each point of the steel cage processing platform 10; the hydraulic jack 9-1 is arranged on the bottom surface of the steel cage processing platform 10 to reduce the deformation of the steel cage processing platform 10 and keep it stable. The strain gauge 9-2 is connected to the signal acquisition instrument 9-1 through a wire, and the strain gauge 9-2 and the hydraulic jack 9-3 should be avoided from being arranged on the bottom surface of the steel cage processing platform 10 and the contact surface of the hydraulic jack 9-3, respectively, to avoid damage to the strain gauge 9-2.

[0067] The steel cage 11 is reinforced by an I-shaped reinforcement rib 11-3, an X-shaped reinforcement rib 11-4 and a W-shaped reinforcement rib 11-5; the X-shaped reinforcement rib 11-4 is arranged in the transverse direction of the steel cage body 11-2, and the W-shaped reinforcement rib 11-5 is arranged in the longitudinal direction of the steel cage body 11-2, so as to prevent the steel cage 11 from being excessively deformed during the lifting process; the spacing between each X-shaped reinforcement rib 11-4 and the W-shaped reinforcement rib 11-5 should be 3 meters; lifting rings 11-1 are provided at the X-shaped reinforcement rib 11-4 and the W-shaped reinforcement rib 11-5 for lifting the steel cage 11; all lifting points arranged on the upper frame of the steel cage 11 are required to be provided with an I-shaped reinforcement rib 11-3 to avoid excessive deformation of the lifting points of the steel cage 11.

[0068] The end hole backfill system 13 includes an H-shaped steel 13-3 and a backfill bag 13-5; the bottom of the H-shaped steel 13-3 extends to the bottom elevation of the excavated trench section 13-2 and is inserted into the soil by 50 cm to block the concrete and mortar from flowing around the bottom of the head steel plate; a grout-stopping iron sheet 13-1 is fixed on both sides of the steel cage 11 to block the mortar from flowing around the outer side of the H-shaped steel 13-3; the backfill bag 13-5 is backfilled at the joint of the H-shaped steel 13-3, and the backfill bag 13-5 is excavated after the concrete pouring is completed.

[0069] The underground continuous wall opening system 15 includes a retaining wall 15-1 and a steel section 15-2 for drilling; the retaining wall 15-1 is arranged inside the underground continuous wall 14; the steel section 15-2 for drilling is installed on the retaining wall 15-1; the unit block cutting holes 15-3 are arranged at the four corners of each unit block; the sleeve embedded holes 15-4 are arranged at the center of each unit block; a unit block lifting ring 15-5 is provided on each unit block for lifting out the cut unit block; a steel wedge 15-6 is fixed in each hole, and a sleeve is fixed at the center of the steel wedge 15-6.

[0070] When the underground pipeline 4 is completely excavated, a rectangular box 3 is made according to the size of the underground pipeline 4 for wrapping and protection; the length of the rectangular box 3 should exceed the thickness of the underground continuous wall 14, and a certain length should be left to anchor into the guide wall 5-5, generally greater than 30 cm.

Claims

1. A construction method for an underground continuous wall system, characterized in that: The following steps are involved: Step 1: The gantry column (1-1) is arranged along the center line (1-3) of the underground continuous wall, and the guide wall excavation positioning line (1-4) is arranged along the fine line (1-2) arranged on the gantry column (1-1); and a trench is excavated along the guide wall excavation positioning line (1-4) using an excavator (2); Step 2: installing a guide wall support (5-3), a guide wall formwork (5-4) and a concrete delivery pipe (5-2) in the trench, and after pouring the guide wall (5-5), removing the guide wall formwork (5-4) and installing an internal support; Step 3: Use a high-power rotary drilling rig (6) to drill a hole, a slotting machine (7) to grab the upper soil, and a slot milling machine (8) to mill the rock layer; Step 4: monitor whether the steel cage processing platform (10) is level by means of a strain gauge (9-2) and a signal acquisition instrument (9-1), and adjust the levelness by means of a hydraulic jack (9-3); process the steel cage (11) on the steel cage processing platform (10); the strain gauge (9-2) is installed on the bottom surface of the steel cage processing platform (10), and the hydraulic jack (9-3) is also arranged on the bottom surface of the steel cage processing platform (10); the strain gauge (9-2) is connected to the signal acquisition instrument (9-1) via a wire, and the strain gauge (9-2) and the hydraulic jack (9-3) are respectively arranged on the steel cage processing platform The steel cage (11) is provided at different positions on the bottom surface of the platform (10); the steel cage (11) comprises a steel cage body (11-2), a "J"-shaped reinforcement rib (11-3), an X-shaped reinforcement rib (11-4) and a W-shaped reinforcement rib (11-5); the X-shaped reinforcement rib (11-4) is arranged in the transverse direction of the steel cage body (11-2), and the W-shaped reinforcement rib (11-5) is arranged in the longitudinal direction of the steel cage body (11-2); lifting rings (11-1) are provided at the X-shaped reinforcement rib (11-4) and the W-shaped reinforcement rib (11-5); all lifting points of the upper frame of the steel cage (11) are provided with "J"-shaped reinforcement ribs (11-3); Step 5: Install a wall brushing blade (12) on the troughing machine (7) to clean the trough wall; put in the steel cage (11) and pour concrete; Step 6: Align the bottom of the H-shaped steel (13-3) with the bottom elevation of the excavated trench section (13-2); fix the grout-stopping iron sheet (13-1) on both sides of the steel cage (11); and backfill the earth bag (13-5) at the joint of the H-shaped steel (13-3); Step 7, a retaining wall (15-1) is arranged on the inner side of the underground continuous wall (14) and a drilling steel section (15-2) is installed on the retaining wall (15-1); after the cutting holes (15-3) are cut along the unit blocks, the unit blocks are lifted out and the holes are sealed by using steel wedges (15-6) and sleeves (15-7); the drilling steel section (15-2) is installed on the retaining wall (15-1); the retaining wall (15-1) is divided into a plurality of unit blocks according to the cutting requirements, and the unit block cutting holes (15-3) are evenly distributed at the four corners of each unit block; a casing pre-buried hole (15-4) is arranged at the center of each unit block; each unit block is also provided with a unit block lifting ring (15-5); a steel wedge (15-6) is fixed in each hole formed after the unit block is cut, and a sleeve (15-7) is fixed at the center of the steel wedge (15-6).

2. The construction method of the underground continuous wall system according to claim 1, characterized in that: In step one, the thin wire (1-2) is tied to the gantry column (1-1), and before the excavator (2) is used for construction, manual excavation is performed to the bottom of the underground pipeline (4), and a rectangular box (3) is added outside the underground pipeline (4).

3. The construction method of the underground continuous wall system according to claim 1, characterized in that: In the second step, a guide wall support (5-3), a guide wall formwork (5-4) and a concrete delivery pipe (5-2) are arranged in the groove, and concrete of the guide wall (5-5) is poured symmetrically. After the concrete strength of the guide wall (5-5) reaches 80% of the design strength, the guide wall formwork (5-4) is removed; after the guide wall formwork (5-4) is removed, a safety mesh is laid on the top of the guide wall (5-5), and internal supports are arranged, the internal supports comprising a transverse internal support (5-6), a longitudinal internal support (5-7) and an adjustable support (5-8); a plurality of transverse internal supports (5-6) are arranged at different heights of the guide wall (5-5), and the transverse internal supports (5-6) at different heights are connected and reinforced by the longitudinal internal support (5-7), and the bottom of the transverse internal support (5-6) is also reinforced and supported by the adjustable support (5-8).

4. The construction method of the underground continuous wall system according to claim 1, characterized in that: In step 6: insert the H-shaped steel (13-3) into the soil to a depth of 50 cm; after the concrete pouring is completed, remove the earthfill bag (13-5).

5. An underground continuous wall system, characterized in that: Obtained by the method according to any one of claims 1 to 4.

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