Cross stereo type passage pre-reinforcement and hole construction method

Abstract

The application discloses a kind of cross stereo type passage pre-reinforcement and hole construction method, it is related to the field of construction, technical scheme is, including S1, pile after soil body reinforcement;S2, pre-opening hole mouth is set with channel steel cross support;S3, hole mouth upper pile body integral reinforcement;S4, hole mouth break;S5, to the pile body that has been cut off double-row type steel beam lateral support reinforcement;S6, steel column is supported;S7, pile body break;S8, backfill;S9, upper layer communication construction;S10, upper side communication connection mouth part pile body cut off and reinforcement;S11, break wall body.The beneficial effects of the application are: using "first down then up", first lower structure construction, then upper structure construction;"first support then remove", support before removal, ensure safety before pile removal;"reinforcement simultaneously", after pile foundation removal, reinforcement simultaneously, ensure construction safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building construction, in particular to a cross-stereoscopic passage pre-reinforcement and hole-opening construction method. BACKGROUND

[0002] In urban planning, the projects near the subway are mostly commercial complexes. In order to drive the development of business, the buildings around the subway are often connected with the subway station to form a subway traffic and commercial center. However, in the case that the project site is not close to the subway station but the rail transit penetrates the site, in order to increase the business potential and ensure the normal operation of the rail transit, the project site also needs to be connected to form a whole. This kind of situation often becomes the focus of the design and construction of the near-subway project. When the underground rail transit (or subway) construction needs to be reconnected after completion, the main design scheme is to reserve the passage structure in the side wall of the existing structure for connection treatment, so as to make the basement whole. However, due to the complex stress of the underground structure, there is a great risk in the process of breaking the existing underground structure and handling the connection interface. Moreover, there is a big difference between the stress states of the new and old structure foundations, and it is very likely that the uneven settlement of the new and old buildings will cause the interface to crack or even the structure to be damaged. Therefore, how to effectively solve the stress and waterproof treatment of the connection interface is also the key to the connection construction of the rail transit.

[0003] Through the research on the connection of the existing subway station in recent years, it can be seen that the connection problem is a complex technical problem that has appeared in recent years. Previous studies have found the influence law of the opening of the subway station structure on the structure stress, but the research is mostly concentrated in one opening direction. However, for the cross-stereoscopic station passage connection, the opening type is more diverse, so it is necessary to develop a near-existing underground structure stereoscopic connection construction method. SUMMARY

[0004] In view of the above technical problems, the present application provides a cross-stereoscopic passage pre-reinforcement and hole-opening construction method.

[0005] The technical scheme comprises the following steps:

[0006] S1, post-pile soil reinforcement: before cutting the pile, the post-pile soil is grouted and reinforced, and the grouting operation range should be the outer edge of the pre-opening hole;

[0007] S2, setting a cross support of channel steel above the pre-opening hole: a cross support of channel steel is arranged outside the first row of support piles above the pre-opening hole, the pre-cut pile and the adjacent piles on both sides are connected into a whole, and a pre-embedded part is installed on the pile above the pre-opening hole;

[0008] S3, whole reinforcement of upper pile body of hole mouth: after the cross support of channel steel is installed, the whole reinforcement of the upper pile body of the hole mouth is carried out, and drilling is carried out on each pile body above the hole mouth, the drilling depth penetrates the three rows of pile bodies, and after drilling, a steel pipe is inserted, and grouting is carried out inside and outside the steel pipe;

[0009] S4, hole breaking: after the grouting reaches the design strength, when two passages need to be connected for construction, the lower hole needs to be broken first, and then the upper hole is broken;

[0010] S5, double-row steel beam transverse support reinforcement for the cut pile body: after the first row of support piles double-row steel beam installation near area pile body part cutting is completed, the cut pile body is transversely supported and reinforced by double-row steel beam;

[0011] S6, steel column is set: after the double-row steel beam connection at the corner is completed, the steel column is directly set at the bottom of the cross double-row steel beam at the corner;

[0012] S7, pile breaking: the remaining pile body in the first row is broken to the designed size by the static breaking method, and the second row of piles and the third row of piles are broken, the passage structure wall is broken, and the connecting passage interface is poured;

[0013] S8, backfilling: after the lower layer support structure is broken and reinforced, the lower layer main body structure is constructed, and the plain concrete or plain soil backfilling is carried out; if the inner support is arranged in the foundation pit, the inner support in the foundation pit is removed after the backfilling is completed, so as to expand the construction space of the upper layer structure;

[0014] S9, upper layer connecting connection port construction: after the lower layer structure is completely constructed, the upper layer connecting construction is carried out, and the upper layer connecting connection port is generally located on the side of the lower layer hole mouth, and is arranged according to the actual underground structure function requirement;

[0015] S10, part of the pile body of the upper layer connecting connection port is cut and reinforced: part of the first row of pile bodies is cut in advance to provide space for the subsequent installation of the double-row steel beam, and part of the pile body near the first row of support piles double-row steel beam installation area is cut, and the second row of piles and the third row of piles are reinforced and broken;

[0016] S11, wall breaking: after the reinforcement and breaking of the three rows of piles are completed, the wall is broken by using the rope saw static cutting process and assisting the light electric jack.

[0017] Preferably, the embedded part in step S2 includes a steel plate with holes and long screws, a slot is formed in the middle of the steel plate, and two long screws are arranged in the slot, and the screws are welded with the steel plate.

[0018] Preferably, due to pile body construction error and stratum difference, the pile body position is not consistent, and step S2 further includes three cases:

[0019] S201, convex pile body: before installing the embedded part, the curved surface of the pile side should be planed flat, and the planed surface size is expanded by 50mm outside the flat surface size of the connecting steel plate;

[0020] S202, concave pile body: first drill a hole according to the installation position of the long screw rod of the embedded part, then insert the long screw rod on the steel plate into the hole, then support the formwork around the steel plate and grout, the channel steel is welded with the new steel plate to form a whole, forming a cross truss, and a pair of parallel strain gauges are installed at the intersection of the cross support;

[0021] S203, when the hole is large and located at the corner of the foundation pit: set up channel steel cross supports on the planes on both sides of the hole respectively, and the two side channel steel supports are connected with the two non-cutting pile bodies respectively, and the other end of the two groups of channel steel supports are welded as a whole by the steel plate.

[0022] Preferably, the specific steps in step S3 are: installing a double-hole grouting stopper at the end of the drill hole.

[0023] Preferably, the specific steps in step S4 are: cutting off part of the pile in advance, and adding a steel column at the corner of the steel beam for support.

[0024] Preferably, the specific steps in step S5 are: the double-row steel beam connection method includes steel pad connection, embedded part connection, and double-row steel beam connection at the corner of the double-row steel beam, and the two ends of the double-row steel beam are welded with the embedded part and the existing pile body reinforcement, and after welding is completed, grouting is sealed, and the grouting material is selected from cement-based material or anchoring glue.

[0025] Preferably, the specific steps in step S6 are: setting an axial force meter on the upper part of the steel column, and setting a corbel on both ends of the steel column.

[0026] The steel column bottom is fixed to the bottom foundation through the column foot anchor bolt and the steel pad, and the top end of the steel column is welded and connected with the bottom steel pad of the axial force meter.

[0027] Preferably, step S7 further comprises:

[0028] S701: the remaining pile body in the first row is broken to the designed size by a static breaking method, and the removal sequence is from the corner to both sides;

[0029] S702: after the first row of piles is reinforced, the second row of water stop curtain pile bodies are broken;

[0030] S703: after the second row of piles is broken, the third row of piles is broken, and the method is the same as step S701.

[0031] Preferably, the specific steps in step S8 are: after the lower layer of supporting structure is broken and reinforced, the lower layer of main structure is constructed, and the plain concrete or plain soil is backfilled.

[0032] Preferably, step S9 further comprises:

[0033] S901: cutting off the first row of pile bodies in advance, the position of cutting is above the pre-cut hole, and the cut pile bodies are symmetrically cut from the middle to both sides, and the cut pile bodies are transversely supported and reinforced by double-row steel beams;

[0034] S902: after the first row of piles is reinforced, the second row of waterproof curtain pile bodies is reinforced and broken;

[0035] S903: after the second row of piles is broken, the third row of piles is broken, and the cut pile bodies are transversely supported and reinforced by double-row steel beams.

[0036] The technical scheme provided by the embodiment of the application has the beneficial effects that: 1. The application discloses a new method for comprehensive reinforcement and construction of a deep foundation pit near an existing underground structure in a cross-stereoscopic complex connection, which adopts the method of "first down and then up", that is, the lower structure is constructed first, and then the upper structure is constructed; the method of "first support and then remove", that is, support is performed before removal to ensure safety, and then the pile is removed; and the method of "reinforcement synchronization", that is, reinforcement is performed simultaneously after the pile foundation is removed, to ensure construction safety. The influence on the existing structure during construction in a cross-stereoscopic complex situation is minimized, and the safety of the existing structure is ensured.

[0037] 2. Before cutting the pile bodies, cross-slots are used to pre-reinforce the upper pile bodies of the hole, and especially for a stereoscopic hole, adjacent planes of the cross-slots are welded and reinforced to form a cross-truss, so as to enhance the integrity of the support structure and ensure that the structural deformation caused by the redistribution of internal forces during the breaking of the existing pile bodies is within the control range.

[0038] 3. By drilling holes in the pile bodies and inserting steel pipes for post-pouring, the first row of piles, the second row of waterproof curtains, and the third row of piles are connected as a whole to jointly bear the earth pressure, reduce the horizontal or vertical displacement caused by pile breaking construction, and improve the support effect of the three rows of pile bodies.

[0039] 4. Steel support columns are arranged at the position of the stereoscopic hole, flanges and corbels are arranged at the top of the steel support columns, the load of the upper pile bodies can be effectively transmitted to the columns, the connection and construction are safer, and unnecessary personnel casualties and economic losses are avoided.

[0040] 5. Double-hole grouting stoppers are installed at the end of the drilled holes, which are different from conventional single-hole stoppers, can effectively block the grout inside the steel pipe and the grout between the outer wall of the steel pipe and the pile body, fully ensure the grouting quality, and provide a premise for the effective transmission of the load of the pile bodies by the steel pipe.

[0041] 6. The construction plan fully considers the opening size problem caused by the steel beams. A stepped opening reinforcement method is adopted to adjust the opening size to meet the feasibility of subsequent construction and ensure the space for opening and connection construction.

[0042] 7. The newly added embedded parts are easy to install, which can flexibly solve the problem of different pile positions. In addition, the steel plate of the embedded parts can be disassembled and recycled, reducing material costs.

[0043] 8. The shear wall opening adopts the static cutting process of wire saw, assisted by a light electric pick, which effectively ensures that the shear wall of the existing station is demolished with reasonable force and safe force system conversion, and reduces the impact on the stability of the existing structure.

[0044] 9. To ensure safety and control displacement deformation during later construction, steel reinforcement and support are adopted, and strain gauges are installed on the steel sections (to facilitate real-time monitoring of the stress and deformation of the double-row steel beams), thereby ensuring the safety of the construction work surface. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the overall construction area according to an embodiment of the present invention.

[0046] Figure 2 This is a top view of the pre-reinforced steel pipe according to an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of the lower opening being broken in an embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of the transverse support and reinforcement of the double-row steel beam with removed piles according to an embodiment of the present invention.

[0049] Figure 5 This is a schematic diagram of the removal of the first row of remaining piles in an embodiment of the present invention.

[0050] Figure 6 This is a schematic diagram of the breaking of the second row of water-stop curtain in an embodiment of the present invention.

[0051] Figure 7 This is a schematic diagram of the breaking of the third row of piles in an embodiment of the present invention.

[0052] Figure 8 This is a schematic diagram of the broken opening in an embodiment of the present invention.

[0053] Figure 9 This is a schematic diagram of soil backfilling according to an embodiment of the present invention.

[0054] Figure 10 This is a schematic diagram of the removal of part of the first row of piles at the upper opening in an embodiment of the present invention.

[0055] Figure 11It is the upper hole first row pile body lateral support reinforcement schematic view of the embodiment of the application.

[0056] Figure 12 It is the upper hole second row waterproof curtain breaking schematic view of the embodiment of the application.

[0057] Figure 13 It is the upper hole third row breaking schematic view of the embodiment of the application.

[0058] Figure 14 It is the wall breaking schematic view of the embodiment of the application.

[0059] Figure 15 It is the grout stop structure schematic view of the embodiment of the application.

[0060] Figure 16 It is Figure 15 The sectional view of the 1-1 direction.

[0061] Wherein, the reference signs are: 1, first row pile; 2, channel steel; 3, embedded part; 4, steel pipe; 5, upper hole; 6, lower hole; 7, pre-grouting area; 8, foundation; 9, crown beam; 10, second row pile; 11, third row pile; 12, steel column; 13, shaped steel beam; 14, strain gauge; 15, axial force meter; 16, second row pile cutting cross section; 17, shear wall; 18, breaking hole; 19, backfill; 20, passage; 21, grout stop; 22, grouting port. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the application more clear, the application is further described in detail below in combination with the drawings and embodiments. Of course, the specific embodiments described here are only used to explain the application, and are not used to limit the application.

[0063] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0064] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0065] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0066] Embodiment 1

[0067] Referring to Figures 1 to 14 The present application provides a cross stereoscopic channel pre-reinforcement and hole opening construction method, comprising the following steps:

[0068] S1, post-pile soil reinforcement: before cutting the pile, the post-pile soil is grouted and reinforced, the grouting operation range should be the outer edge of the pre-hole opening, and the pre-grouting area 7 should be larger than the range of the pre-hole opening;

[0069] S2, setting channel steel 2 cross support above the pre-hole opening: setting channel steel 2 cross support outside the first row of support piles above the pre-hole opening, connecting the pre-cut pile and the adjacent piles on both sides into a whole, and installing embedded parts 3 on the pile body above the pre-hole opening;

[0070] S3, overall reinforcement of the upper pile body of the hole: after the installation of the channel steel 2 cross support is completed, the upper pile body of the hole is overall reinforced, drilling is performed on each pile body above the hole, the drilling depth penetrates three rows of pile bodies, and after drilling, steel pipes 4 are inserted, and the inside of the steel pipes 4 and the outside of the steel pipes 4 are grouted;

[0071] S4, hole breaking: after the grouting reaches the design strength, when the two passages 20 need to be connected for construction, the lower hole 6 needs to be broken first, and then the upper hole 5 is broken;

[0072] S5, double-row steel beam 13 lateral support reinforcement for the cut pile: after the first row of support piles double-row steel beam 13 installation near the area pile part cut off, the cut pile is laterally supported and reinforced by double-row steel beam 13;

[0073] S6, steel column 12 is set: after the completion of the corner double-row steel beam 13 connection, steel base plate is added at the bottom of the intersection double-row steel beam 13 at the corner to set steel column 12;

[0074] S7, pile breaking: the first row of lower remaining piles are broken to the designed size by static breaking method, and the second and third rows of piles are broken, the passage structure wall is broken, and the connecting passage interface is poured;

[0075] S8, backfilling: after the lower support structure is broken and reinforced, the lower main structure is constructed, and the plain concrete or plain soil is backfilled; if there is an internal support in the foundation pit, the internal support in the foundation pit is removed after backfilling to expand the construction space of the upper structure;

[0076] S9, upper connecting construction: after the lower structure is completely constructed, the upper connecting construction is carried out, and the upper connecting connection is generally located on the side of the lower hole, which is set according to the actual underground structure function;

[0077] S10, upper side connecting connection part pile cutting and reinforcement: pre-cutting part of the first row of piles provides space for subsequent installation of double-row steel beam 13, and the first row of support piles double-row steel beam 13 installation near the area pile part is cut off, and the second and third rows of piles are reinforced and broken;

[0078] S11, wall breaking: after the reinforcement and breaking of the three rows of piles are completed, the wall is broken by using the rope saw static cutting process assisted by light electric jack.

[0079] The embedded part 3 in step S2 includes a steel plate with holes and long screws, a slot is opened in the middle of the steel plate, and two long screws are arranged in the slot, and the screws are welded with the steel plate.

[0080] Due to pile construction error and stratum difference, the pile position is not consistent, and step S2 also includes three cases:

[0081] S201, convex pile body: before installing the embedded part 3, the curved surface of the pile side should be planed flat, and the planed surface size is 50mm larger than the connecting steel plate plane size; the hole can be drilled in the pile body in advance according to the long screw rod position of the embedded part 3, and the anchoring glue is smeared between the embedded part 3 steel plate and the planed surface and in the drilled hole, so as to ensure the firm connection of the pile body and the embedded part 3;

[0082] S202, recessed pile body: first drill a hole according to the long screw rod installation position of the embedded part 3, insert the long screw rod on the steel plate into the hole, then support the mold around the steel plate and grout, firmly connect the embedded part 3 with the existing pile body structure, weld the channel steel 2 and the new steel plate to form an integral whole, and form a cross truss; a pair of parallel strain gauges 14 are installed at the intersection of the cross support to facilitate real-time monitoring of the stress deformation of the profile steel; after the installation of the channel steel 2 cross support is completed, the subsequent work can be started;

[0083] S203, when the hole is large and located at the corner of the foundation pit: the pre-opening hole is not in one plane, but a three-dimensional hole, and the channel steel 2 cross supports are arranged on the planes on both sides of the hole, and the two side channel steel 2 supports are connected with the pile bodies not cut off on both sides, and the other end of the two groups of channel steel 2 supports are welded as a whole by the steel plate.

[0084] The specific steps in step S3 are: a double-hole grouting stopper 21 is installed at the end of the drill hole, the stopper 21 includes a circular plate-shaped end plate, an annular sleeve-shaped inner layer stopper and an outer layer stopper are fixedly arranged on one side of the end plate, a valve is fixedly arranged in the middle of the other side of the end plate, a tubular grouting port 22 and an exhaust hole are respectively arranged on the bodies of the inner layer stopper and the outer layer stopper, one end of the grouting port 22 and the exhaust hole penetrates the end plate, the grouting port 22 facilitates the operator to grout inside and outside the steel pipe, and the exhaust hole can exhaust the gas in the hole to the outside of the stopper 21;

[0085] The inner layer stopper and the outer layer stopper are inflatable rubber capsules, and the inner layer stopper and the outer layer stopper are inflated and deflated through the valve, so as to facilitate the hole to be blocked by the stopper 21, the inner layer stopper is inserted into the inside of the steel pipe 4 to block the inside, and the outer layer stopper blocks the outside of the steel pipe 4;

[0086] The stopper 21 prevents the leakage of slurry, after the initial setting of the concrete in the drill hole, the valve is opened, the inner layer stopper and the outer layer stopper are deflated, the stopper 21 can be pulled out, the three rows of piles are connected as a whole through the steel pipe 4, the safety during the opening of the hole is ensured, and after the maintenance reaches the design concrete strength, the subsequent construction can be carried out. The stopper 21 can effectively block the slurry between the inside of the steel pipe and the slurry between the outer wall of the steel pipe and the pile body, fully ensuring the grouting quality, and providing a premise for the effective transmission of the pile load by the steel pipe.

[0087] The specific step in step S4 is to cut off the pre-cut pile to provide space for subsequent installation of the double-row steel beam 13 and steel column 12, and the starting position of the pile breaking should be determined according to the design opening requirements, the height and the number of double-row steel beams 13, the size of the opening is expanded, the height is expanded by about 200-300 mm, and the width is expanded by about twice the pile diameter, and the cutting position is located above the pre-cut opening;

[0088] When the cross stereo opening construction is carried out, the opening is not a plane, and a steel column 12 needs to be added at the corner of the steel beam 13 for support, so the whole pile at the corner needs to be broken, and the breaking range needs to meet the support requirements of the steel column 12, about one pile diameter, and the cutting height needs to meet the installation requirements of the double-row steel beam 13. When cutting the pile, it is cut symmetrically from the middle to both sides, the bottom surface and the side surface of each pile need to be smooth and smooth to ensure that the double-row steel beam 13 is installed more evenly. For the adjacent side of the pile to be broken, 1 / 2 of the cross section near the opening is cut, in principle, the concrete is broken, but the original steel bar remains unchanged, and the steel wire brush is used to clean the surface of the steel bar. Need to be poured with double-row steel beam 13 for stress.

[0089] The specific steps in step S5 include steel pad connection, pre-embedded part 3 connection, and double-row steel beam 13 connection at the corner of the double-row steel beam 13. Steel pads are added to the bottom cross section of the pile to be cut off using a steel pad, and pre-embedded parts 3 are embedded in the adjacent piles on both sides. The bottom of the double-row steel beam 13 is provided with an axial force meter 15, and the two ends of the double-row steel beam 13 are welded with the pre-embedded part 3 and the existing pile steel bar. After welding, the grouting is sealed, and the grouting material is selected from cement-based material or steel bar glue;

[0090] The corner of the double-row steel beam 13 is located at the corner pile, and is connected by welding. Specifically, the flange of one side of the double-row steel beam 13 is cut off, and then inserted into the web of the other side of the double-row steel beam 13 and welded with the web.

[0091] The specific steps in step S6 are that the axial force meter 15 is arranged at the upper part of the steel column 12, and the corbel is arranged at both ends of the column.

[0092] When the steel column 12 is supported, the cross section of the broken pile should be flat, and high-strength polymer mortar is used for repair and leveling if necessary to ensure the perpendicularity of the steel column 12.

[0093] The bottom of the steel column 12 is fixed to the bottom foundation 8 through the column foot anchor bolt and the steel pad, and the top of the column is welded and connected with the bottom steel pad of the axial force meter 15.

[0094] Step S7 further includes:

[0095] S701: The first row of lower remaining pile bodies are broken to the designed size by the static force breaking method, and the removal sequence is from the corner to both sides, and the specific method is to cut off the pile body by using a rope saw, and each section is cut off about 1-1.5 m;

[0096] S702: After the first row of piles 1 are reinforced, the second row of waterproof curtain pile bodies are broken, when the foundation pit supporting structure is close to the existing structure or the distance is small, and the soil between the foundation pit supporting structure and the original supporting structure of the existing structure is less, the soil behind the waterproof curtain is removed at the same time of removing the waterproof curtain, and the specific method can be to use a manual air pick combined with an oil drill until the shear wall 17 is leaked;

[0097] If the strength of the soil behind the cement soil is not high, a small guide pipe should be used to grout and reinforce the soil in the excavation area before excavation, and at the same time, shotcrete with a mesh is used for excavation, and if the strength is sufficient, shotcrete with a mesh can be directly used;

[0098] S703: After the second row of piles 10 are broken, the third row of piles 11 are broken, and the method is the same as step S701; the breaking range should be based on the height and the number of the double-row type steel beams 13 to determine the setting range of the double-row type steel beams 13 and the pile breaking range after the second row of piles 10 are broken.

[0099] The specific steps in step S8 are: after the lower supporting structure is broken and reinforced, the lower main body structure is constructed, and the backfill soil 19 is generally plain concrete or plain soil;

[0100] If there is an internal support in the foundation pit, the internal support in the foundation pit is removed after backfilling to expand the construction space of the upper structure.

[0101] Step S9 also includes:

[0102] S901: The first row of partial pile bodies are cut off in advance to provide space for the subsequent installation of the double-row type steel beams 13; the starting breaking position of the pile body should be determined according to the design opening requirements, the height and the number of the double-row type steel beams 13 to expand the size of the opening, the height is expanded by about 200-300 mm, and the width is expanded by about one or two pile diameters;

[0103] The pile cutting position is above the pre-cut opening, and the cutting height needs to meet the installation requirements of the double-row type steel beams 13; the pile is cut symmetrically from the middle to both sides, and the cut bottom surface and side surface of each pile body need to be smooth;

[0104] After the partial cutting of the pile body in the area near the installation of the double-row steel beam 13 of the first-row support pile, the double-row steel beam 13 is used for transverse support and reinforcement of the cut pile body; the connection method of the double-row steel beam 13 is steel pad connection; a steel pad is added to the bottom section of the pile body to be cut by using a plant glue, the steel pad is welded with the steel beam 13, an axial force meter 15 is arranged at the bottom of the two ends of the double-row steel beam 13, and a pair of parallel strain gauges 14 are installed on the double-row steel beam 13;

[0105] The remaining pile body at the lower part of the first row is broken to the designed size by using a static breaking method; the removal sequence is from the middle to the two sides; the specific method is to cut the pile body by using a rope saw, and each cutting is about 1-1.5 m, which is convenient for hoisting and transportation;

[0106] S902: After the reinforcement of the first-row pile 1, the reinforcement and breaking of the second-row waterproof curtain pile body are performed; due to the reinforcement of the first-row pile 1, the breaking range here is smaller than that of the first-row pile 1; when the foundation pit support structure and the existing structure are closely connected or the distance is small, and the soil body between the foundation pit support structure and the original support structure of the existing structure is small, the soil body behind the waterproof curtain is removed when the waterproof curtain is removed;

[0107] If the strength of the soil body behind the cement soil is not high, a small guide pipe should be used to grout and reinforce the soil body in the excavation area before excavation, and shotcrete with a mesh is used for excavation; if the strength is sufficient, shotcrete with a mesh can be directly used;

[0108] S903: After the breaking of the second-row pile 10 is completed, the breaking of the third-row pile 11 is performed; due to the reinforcement of the second-row pile 10, the breaking range here is smaller than that of the second-row pile 10; after the partial cutting of the pile body in the area near the installation of the double-row steel beam 13 of the third-row support pile is completed, the double-row steel beam 13 is used for transverse support and reinforcement of the cut pile body;

[0109] The connection method of the double-row steel beam 13 includes steel pad connection, pre-embedded part 3 connection, and double-row steel beam 13 connection at the corner of the double-row steel beam 13;

[0110] A steel pad is added to the bottom section of the pile body to be cut by using a plant glue, and a pre-embedded part 3 is pre-embedded in the adjacent pile bodies on both sides which are not cut, so as to facilitate the fixation of the two ends of the double-row steel beam 13; an axial force meter 15 is arranged at the bottom of the two ends of the double-row steel beam 13, and the two ends of the double-row steel beam 13 are welded with the pre-embedded part 3 and the steel reinforcement of the existing pile body;

[0111] After welding is completed, plugging and grouting are performed, and the grouting material is selected from cement-based material or plant glue; in order to facilitate the real-time monitoring of the stress deformation of the steel, a pair of parallel strain gauges 14 are installed on the double-row steel beam 13.

[0112] The above merely preferred embodiments of the present application and are not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for cross-stereoscopic passage pre-reinforcement and hole construction, characterized in that, The method comprises the following steps: S1, pile post soil body reinforcement: before cutting piles, the soil body behind the piles is grouted and reinforced, and the grouting operation range should be the outer edge of the pre-opening hole; S2, setting channel steel (2) cross support above the pre-opening hole: setting channel steel (2) cross support outside the first row of support piles above the pre-opening hole, connecting the pre-cut pile and the adjacent piles on both sides into a whole, and installing embedded parts (3) on the pile body above the pre-opening hole; S3, overall reinforcement of the upper part of the hole: after the installation of the channel steel (2) cross support is completed, the upper part of the hole is reinforced as a whole, drilling is performed on each pile body above the hole, the drilling depth penetrates through three rows of pile bodies, a steel pipe (4) is inserted after drilling, and the inside of the steel pipe (4) and the outside of the steel pipe (4) are grouted; S4, hole breaking: after the grouting reaches the design strength, when two passages (20) need to be connected for construction, the lower hole needs to be broken first, and then the upper hole is broken; S5, double-row steel beam (13) lateral support reinforcement for the cut pile body: after the first row of support piles double-row steel beam (13) is installed, the cut pile body is laterally supported and reinforced by the double-row steel beam (13); S6, steel column (12) is supported: after the connection of the double-row steel beam (13) at the corner is completed, the steel column (12) is directly supported at the bottom of the double-row steel beam (13) at the corner; S7, pile body breaking: the remaining pile body in the first row is broken to the designed size by the static breaking method, and the second row of piles and the third row of piles are broken, the passage structure wall is broken, and the connected passage joint is poured; S8, backfilling: after the lower support structure is broken and reinforced, the lower main structure is constructed, and the concrete or soil backfilling is performed; if there is an internal support in the foundation pit, the internal support in the foundation pit is removed after the backfilling is completed to expand the upper structure construction space; S9, upper connected joint construction: after the lower structure is completely constructed, the upper connected joint construction is performed, the upper connected joint is located on the side of the lower hole, and is set according to the actual underground structure function needs; S10, upper connected joint partial pile body cutting and reinforcement: the first row of pile bodies is cut in advance to provide space for the subsequent installation of the double-row steel beam (13), the first row of support piles double-row steel beam (13) is installed near the area where the pile body is partially cut, and the second row of piles and the third row of piles are reinforced and broken; S11, wall breaking: after the reinforcement and breaking of the three rows of pile bodies are completed, the wall is broken by using the rope saw static cutting process and assisted light electric jack operation.

2. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 1, characterized in that, The embedded part (3) in step S2 comprises a steel plate with holes and long screws, a slot is opened in the middle of the steel plate, and two long screws are arranged in the slot, and the screws are welded with the steel plate.

3. The cross-stereoscopic passage pre-reinforcement and hole-making construction method according to claim 2, characterized in that, Due to pile body construction errors and stratum differences, the pile body positions are not consistent, and step S2 further comprises three cases: S201, convex pile body: before installing the embedded part (3), the curved surface of the pile side should be planed flat, and the planed surface size is 50mm larger than the connected steel plate flat surface size. S202, recess pile body: first, drill a hole according to the embedded part (3) long screw rod installation position, insert the long screw rod on the steel plate into the drilled hole, then support the mold around the steel plate and grout, the channel steel (2) is welded with the newly added steel plate to form a whole, forming a cross truss, and a pair of parallel strain gauges (14) are installed at the intersection of the cross support; S203, when the hole is large and located at the corner of the foundation pit: set up channel steel (2) cross support on the plane on both sides of the hole, respectively, the two side channel steel (2) supports are connected with the two sides of the non-cutting pile body, and the other end of the two groups of channel steel (2) supports are welded into a whole by a steel plate.

4. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 3, characterized in that, The specific steps in step S3 are: installing a double-hole grouting stopper (21) at the end of the drilled hole.

5. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 4, characterized in that, The specific steps in step S4 are: cutting off part of the pile in advance, and adding a steel column (12) at the corner of the steel beam (13) for support.

6. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 5, wherein The specific steps in step S5 are: the double-row steel beam (13) connection method includes steel pad connection, embedded part (3) connection, and double-row steel beam (13) connection at the corner of the double-row steel beam (13), the two ends of the double-row steel beam (13) are welded with the embedded part (3) and the existing pile steel reinforcement, and after welding is completed, grouting is carried out, and the grouting material is selected from cement-based material or anchoring glue.

7. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 6, wherein The specific steps in step S6 are: setting an axial force meter (15) on the upper part of the steel column (12), and setting a corbel on both ends of the column; The bottom of the steel column (12) is fixed in the bottom foundation (8) through column foot anchor bolts and steel pads, and the top of the column is welded and connected with the bottom steel pad of the axial force meter (15).

8. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 7, characterized in that, Step S7 further includes: S701: the remaining pile body in the first row is broken to the designed size by the static breaking method, and the removal sequence is from the corner to both sides; S702: after the first row pile (1) is reinforced, the second row of waterproof curtain pile body is broken; S703: after the second row pile (10) is broken, the third row pile (11) is broken, and the method is the same as step S701.

9. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 8, characterized in that, The specific steps in step S8 are: after the lower supporting structure is broken and reinforced, the lower main structure is constructed, and the plain concrete or plain soil is backfilled.

10. The cross-stereotyped passage pre-reinforcement and opening construction method according to claim 9, wherein Step S9 further includes: S901: cutting part of the pile in the first row in advance, the cutting position is above the pre-cut hole, and the pile is cut symmetrically from the middle to both sides, and the cut pile is transversely supported and reinforced by double-row steel beams (13); S902: after the first row pile (1) is reinforced, the second row of waterproof curtain pile body is reinforced and broken; S903: after the second row pile (10) is broken, the third row pile (11) is broken, and the cut pile is transversely supported and reinforced by double-row steel beams (13).

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