阅读说明：本技术 一种运营高压电缆井顶板临时开孔防护结构及施工方法 (Temporary opening protection structure for top plate of operation high-voltage cable well and construction method ) 是由 周联英 施露 张世民 廖娟 孙苗苗 蒋吉清 张茹 于 2019-09-12 设计创作，主要内容包括：本发明涉及运营高压电缆井顶板临时开孔防护结构,包括既有高压电缆井、既有井井壁、既有井顶板框梁、新建井、开挖边坡、临时孔、植筋、凹槽、无纺布缓冲层、自粘高分子防水卷材、水泥砂浆、碗扣式支架、可调节顶托、密目钢丝网、高压电缆和防火毯；既有高压电缆井的顶板上沿既有井顶板框梁开设临时孔,临时孔的孔口四周设有孔口四周挡水埂；开挖边坡的坡顶和坡底分别设置有地面排水沟和坡底排水沟。本发明的有益效果是：本发明通过对既有运营高压电缆井顶板植筋新建工作井、顶板开孔,以及新旧井交界面防水处理,可以较好地解决因区域电力服务网络完善需要在既有高压电缆井上开孔引线的难题,工艺简便,具有较好的经济效益。(The invention relates to a temporary opening protection structure for a top plate of an operating high-voltage cable well, which comprises an existing high-voltage cable well, an existing well wall, an existing well top plate frame beam, a newly-built well, an excavated side slope, a temporary hole, a planting rib, a groove, a non-woven fabric buffer layer, a self-adhesive high-molecular waterproof coiled material, cement mortar, a bowl buckle type support, an adjustable jacking, a dense mesh steel wire mesh, a high-voltage cable and a fireproof blanket, wherein the existing high-voltage cable well is arranged in the; temporary holes are formed in the upper edge of a top plate of the existing high-voltage cable well along a frame beam of the top plate of the existing well, and water retaining ridges around the holes are arranged on the periphery of the holes of the temporary holes; and a ground drainage ditch and a slope bottom drainage ditch are respectively arranged at the top and the bottom of the excavated side slope. The invention has the beneficial effects that: the invention can better solve the problem that the lead wire needs to be drilled on the existing high-voltage cable well due to the improvement of the regional power service network by performing waterproof treatment on the interface of the new and old well, and has simple and convenient process and better economic benefit.)

1. The utility model provides an operation high tension cable well roof temporary trompil protective structure which characterized in that: the high-voltage cable well comprises an existing high-voltage cable well (1), an existing well wall (2), an existing well roof plate frame beam (3), a newly built well (4), an excavation side slope (5), a temporary hole (8), a planting bar (11), a groove (12), a non-woven fabric buffer layer (14), a self-adhesive high-molecular waterproof coiled material (15), cement mortar (17), a bowl buckle type support (18), an adjustable top support (19), a dense mesh steel wire mesh (20), a high-voltage cable (24) and a fireproof blanket (26); temporary holes (8) are formed in the top plate of the existing high-voltage cable well (1) along the existing well top plate frame beam (3), and water retaining ridges (10) around the orifices are arranged around the orifices of the temporary holes (8); a ground drainage ditch (6) and a slope bottom drainage ditch (7) are respectively arranged at the top and the bottom of the excavated side slope (5); a new well (4) is poured above the temporary hole (8), and the well wall of the new well is positioned on the existing well wall (2) or the existing well top plate frame beam (3) and is connected through the embedded steel bars (11); a groove (12) is reserved on the wall of a newly-built well, a non-woven fabric buffer layer (14) and a self-adhesive high-molecular waterproof coiled material (15) are sequentially paved on the outer side of an interface between a new well and an old well, namely the outer side of the wall of the newly-built well and the upper surface of an existing well top plate, a contraction opening of the wall of the new well is fixed through a cement nail (16), polyurethane sealing paste (13) is filled in the groove (12), and cement mortar (17) is paved on the outer side of the self; a bowl buckle type support (18) is erected below an existing well top plate frame beam (3), an adjustable jacking support (19) is arranged at the upper part of an upright rod of the bowl buckle type support (18), a dense mesh steel wire mesh (20) is laid on the adjustable jacking support (19), and waterproof color stripe cloth (21) is laid on the dense mesh steel wire mesh (20); the high-voltage cable (24) in the existing high-voltage cable well (1) is covered with a fireproof blanket (26).

2. The temporary open hole protective structure of operation high voltage cable well top plate of claim 1, characterized in that: the temporary hole (8) is provided with an orifice steel plate edge covering (9).

3. The temporary open hole protective structure of operation high voltage cable well top plate of claim 1, characterized in that: the vertical rod of the bowl-buckled support (18) is positioned on the bottom plate inside the existing high-voltage cable well (1).

4. The temporary open hole protective structure of operation high voltage cable well top plate of claim 1, characterized in that: a drain hole (22) is arranged at the lowest position in the middle of the waterproof color stripe cloth (21), and a muddy water collecting barrel (23) is arranged below the drain hole (22).

5. A construction method for operating a temporary open hole protective structure of a high voltage cable well roof as recited in claim 1, characterized in that: the method comprises the following steps:

the method comprises the following steps: determining the hole position of the top plate of the existing cable well; according to the structural arrangement of the existing high-voltage cable well (1) and the structure of the existing well roof plate frame beam (3), the position of the existing well roof plate frame beam (3) is avoided, hole sites are arranged along the existing well roof plate frame beam (3), and the structural design of a new well (4) is carried out; the wall of the newly-built well is positioned above the existing well top plate frame beam (3) or the existing well wall (2), and the wall of the newly-built well is poured by planting steel bars on the existing well top plate frame beam (3) or the existing well wall (2);

step two: earth covering and excavating the existing cable well; after the hole site of the existing well roof is determined, measuring and lofting the existing high-voltage cable well (1), and determining the slope of slope release and net hanging and injection support according to the buried depth, soil quality and site conditions; rechecking the set axis again according to the engineering positioning point, and measuring and lofting the pile position according to the axis positioning; when the machine is excavated, the machine parking position avoids the position of the existing high-voltage cable well (1), and underground supporting members are marked; adopting manual excavation when approaching the existing well roof; after the foundation pit is excavated, a ground drainage ditch (6) is arranged at the position of no less than 50cm on the outer side of the slope top, a slope bottom drainage ditch (7) is arranged at the position of the slope foot, and the horizontal distance from the slope foot to the well wall of the newly-built well is no less than 80 cm;

step three: pouring a new well; the wall of the newly built well is positioned above the frame beam (3) of the existing well top plate or the wall (2) of the existing well; double-layer steel bars are planted on the frame beam (3) of the existing well top plate or the well wall (2) of the existing well, so that the well wall of the newly-built well and the existing high-voltage cable well (1) are concreted and cast; the embedded steel bars (11) are embedded into the existing well top plate frame beam (3) or the existing well wall (2) of the well and are not less than 20 cm; then, a steel bar framework is lengthened on the embedded steel bars (11) for pouring the newly built well (4);

step four: existing high-voltage operation cable protection; after the new well (4) is built, protecting the high-voltage cable (24) in the existing high-voltage cable well (1) according to hole positions, and covering a fireproof blanket (26);

step five: setting up a protective bracket under the existing well; before opening the hole, a closed protective bracket under the temporary hole (8) is erected; the protective support is erected in a bowl buckle type support (18), a vertical rod of the bowl buckle type support (18) is erected on a bottom plate in the existing high-voltage cable well (1), an adjustable jacking support (19) is arranged on the upper portion of the vertical rod, a dense mesh steel wire mesh (20) is laid on the adjustable jacking support (19), waterproof color stripe cloth (21) is laid on the dense mesh steel wire mesh (20), and the jacking support is adjusted around the vertical rod to jack the existing well top plate frame beam (3); the jacking is adjusted to ensure that the periphery of the waterproof color stripe cloth (21) is high and the middle of the waterproof color stripe cloth is low, then a drain hole (22) is arranged at the lowest position in the middle of the waterproof color stripe cloth (21), and muddy water is led into a muddy water collecting barrel (23) through a hose for centralized treatment;

step six: opening holes and processing orifices; a hole is formed along the frame beam (3) of the existing well top plate, and hole site lofting is firstly carried out; marking a theoretical position on a well top according to the structural size of an existing well top plate frame beam (3), drilling through the well top plate along four corners with safe distance from the theoretical sideline position of the existing well top plate frame beam (3) by using a concrete core drilling machine, calculating the edge line of the existing well top plate frame beam (3) according to the distance from a hole site in the well top plate to the edge of the existing well top plate frame beam (3), popping out a hole site cutting ink line, cutting a slot by using a concrete pavement slot cutting machine, and then cutting the slot along the inner side of the slot and then taking the hole by using the concrete core drilling machine; after hole taking is finished, the top plate is chiseled in a partitioning mode by an air pick, an angle grinder is used for cutting off steel bars of the top plate, and then the fragments are cleared; after the hole of the top plate is drilled, trimming the periphery of the hole surface, sticking a steel plate edge by using pressure injected epoxy resin glue, and then arranging a water retaining ridge (10) around the hole opening along the outer side of the periphery of the hole opening;

step seven: waterproof treatment of new and old well interfaces; when the wall of the newly-built well is poured, a groove (12) is reserved on the wall of the newly-built well; after the well wall of the newly-built well is poured, waterproof construction of an interface of a new well and an old well is carried out, a non-woven fabric buffer layer (14) is paved, then a self-adhesive high-polymer waterproof coiled material (15) is paved, a seam allowance of the well wall of the newly-built well is fixed by a cement nail (16), a polyurethane sealing paste (13) is filled in a groove (12), and then cement mortar (17) is paved on the outermost layer;

step eight: dismantling protective measures; after the hole opening edge covering and the water retaining ridge are finished, and the concrete slag and the muddy water garbage are cleaned, the protective support is detached; when the support is dismantled, the jacking support is adjusted firstly to be separated from the frame beam (3) of the top plate of the existing well, then the support is dismantled from top to bottom, and the support is moved out of the existing high-voltage cable well.

Technical Field

The invention relates to a temporary hole-opening protection structure, in particular to a temporary hole-opening protection structure for a top plate of an operation high-voltage cable well and a construction method.

Background

With the rapid development of cities and underground spaces, the power transmission lines are changed from overhead conductors to underground laying and are developed towards deeper underground, so that the high-voltage cable tunnel becomes a main development direction. Cable tunnels can involve access and exit problems for high voltage cables. Conventionally, the access and the leading-out of the high-voltage cable are realized through a reserved interface of a tunnel working well wall. Along with city construction's high-speed development, electric power service area network is constantly perfect, and the electric power piping lane is constantly built, needs to meet with existing operation electric power tunnel, must face the interim trompil problem of existing tunnel, including trompil position, the new and old structure of underground meet waterproof problem, the protection problem of existing operation high tension cable.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, provides a method for perforating and leading wires on the roof of an existing high-voltage operation cable well, and pre-protection measures for processing interfaces of new and old structures and perforating construction adjacent to the existing high-voltage operation cable, and solves the problems of temporary perforating and existing operation cable safety caused by the perfection of a power service area network.

The temporary hole opening protection structure for the operation high-voltage cable well top plate comprises an existing high-voltage cable well, an existing well wall, an existing well top plate frame beam, a newly-built well, an excavation slope, a temporary hole, a planting bar, a groove, a non-woven fabric buffer layer, a self-adhesive high-molecular waterproof coiled material, cement mortar, a bowl buckle type support, an adjustable jacking, a dense mesh steel wire mesh, a high-voltage cable and a fireproof blanket; temporary holes are formed in the upper edge of a top plate of the existing high-voltage cable well along a frame beam of the top plate of the existing well, and water retaining ridges around the holes are arranged on the periphery of the holes of the temporary holes; a ground drainage ditch and a slope bottom drainage ditch are respectively arranged at the top and the bottom of the excavated side slope; a newly-built well is poured above the temporary hole, and the well wall of the newly-built well is positioned on the well wall of the existing well or the frame beam of the top plate of the existing well and is connected through embedded bars; a groove is reserved on the wall of the newly-built well, a non-woven fabric buffer layer and a self-adhesive high-molecular waterproof coiled material are sequentially laid on the outer side of the interface of the new well and the old well, namely the outer side of the wall of the newly-built well and the upper surface of the existing well top plate, a contraction opening of the wall of the new well is fixed through a cement nail, polyurethane sealing paste is filled in the groove, and cement mortar is laid on the outer side of the; a bowl buckle type support is erected below an existing well top plate frame beam, an adjustable jacking is arranged at the upper part of a vertical rod of the bowl buckle type support, a dense mesh steel wire mesh is laid on the adjustable jacking, and waterproof color strip cloth is laid on the dense mesh steel wire mesh; the high-voltage cable in the existing high-voltage cable well is covered with a fireproof blanket.

Preferably, the method comprises the following steps: the temporary hole is provided with an orifice steel plate edge.

Preferably, the method comprises the following steps: the vertical rod of the bowl buckle type support is positioned on the bottom plate inside the existing high-voltage cable well.

Preferably, the method comprises the following steps: the lowest position in the middle of the waterproof color stripe cloth is provided with a drain hole, and a muddy water collecting barrel is arranged below the drain hole.

The construction method for operating the temporary open hole protective structure of the high-voltage cable well roof comprises the following steps:

the method comprises the following steps: determining the hole position of the top plate of the existing cable well; according to the structural arrangement of the existing high-voltage cable well and the structure of the existing well roof plate frame beam, avoiding the position of the existing well roof plate frame beam, forming hole sites along the existing well roof plate frame beam, and designing the structure of a newly-built well; the wall of the newly-built well is positioned above the frame beam of the existing well top plate or the wall of the existing well, and the wall of the newly-built well is poured by planting reinforcing steel bars on the frame beam of the existing well top plate or the wall of the existing well;

step two: earth covering and excavating the existing cable well; after the hole site of the existing well roof is determined, measuring and lofting the existing high-voltage cable well, and determining the slope of the slope and the net hanging and spraying support according to the buried depth, the soil quality and the field conditions; rechecking the set axis again according to the engineering positioning point, and measuring and lofting the pile position according to the axis positioning; when the machine is excavated, the machine parking position avoids the position of the existing high-voltage cable well, and the underground supporting member is marked; adopting manual excavation when approaching the existing well roof; after the foundation pit is excavated, arranging a ground drainage ditch at the position of not less than 50cm on the outer side of the slope top, and arranging a slope bottom drainage ditch at the position of the slope foot, wherein the horizontal distance from the slope bottom drainage ditch to the well wall of the newly-built well is not less than 80 cm;

step three: pouring a new well; the wall of the newly built well is positioned above the frame beam of the existing well top plate or the wall of the existing well; the method comprises the following steps that double-layer steel bars are planted on an existing well top plate frame beam or an existing well wall to enable the well wall of a newly-built well and an existing high-voltage cable well to be solidified and poured; the embedded bars are implanted into the frame beam of the existing well top plate or the wall of the existing well not less than 20 cm; then, a steel bar framework is lengthened on the embedded steel bars, and the newly built well is poured;

step four: existing high-voltage operation cable protection; after the new well is built, protecting the high-voltage cable in the existing high-voltage cable well according to hole positions, and covering a fireproof blanket;

step five: setting up a protective bracket under the existing well; before opening the hole, a temporary under-hole closed type protective support is erected; the protective support adopts a bowl buckle type support erecting mode, a vertical rod of the bowl buckle type support is erected on a bottom plate in the interior of an existing high-voltage cable well, an adjustable jacking is arranged at the upper part of the vertical rod, a dense mesh steel wire mesh is laid on the adjustable jacking, waterproof color stripe cloth is laid on the dense mesh steel wire mesh, and the jacking is adjusted around the vertical rod to tightly prop against a frame beam of the existing well top plate; adjusting the jacking to ensure that the periphery of the waterproof color stripe cloth is high and the middle of the waterproof color stripe cloth is low, then arranging a drain hole at the lowest position in the middle of the waterproof color stripe cloth, and introducing muddy water into a muddy water collecting barrel through a hose for centralized treatment;

step six: opening holes and processing orifices; opening holes along the frame beam of the existing well top plate, and firstly performing hole site lofting; marking a theoretical position on a well top according to the structural size of an existing well top plate frame beam, drilling through the top plate by using a concrete core drilling machine along four corners with safe distance from the theoretical sideline position of the existing well top plate frame beam, calculating the edge line of the existing well top plate frame beam according to the distance from a hole position in the top plate to the edge of the existing well top plate frame beam, popping out a hole position cutting ink line, cutting a slot by using a concrete pavement cutting machine, and taking a hole by using the concrete core drilling machine along the inner side of the slot after the slot is cut; after hole taking is finished, the top plate is chiseled in a partitioning mode by an air pick, an angle grinder is used for cutting off steel bars of the top plate, and then the fragments are cleared; after the hole of the top plate is drilled, trimming the periphery of the hole surface, sticking a steel plate for wrapping by adopting pressure epoxy resin glue, and then arranging a water retaining ridge around the hole opening along the outer side of the periphery of the hole opening;

step seven: waterproof treatment of new and old well interfaces; when the wall of the newly-built well is poured, a groove is reserved on the wall of the newly-built well; after the wall of the newly-built well is poured, waterproof construction of a new well interface and an old well interface is carried out, a non-woven fabric buffer layer is laid firstly, then a self-adhesive high-polymer waterproof coiled material is laid, a contraction opening of the wall of the newly-built well is fixed by a cement nail, polyurethane sealing paste is filled in a groove, and cement mortar is laid on the outermost layer;

step eight: dismantling protective measures; after the hole opening edge covering and the water retaining ridge are finished, and the concrete slag and the muddy water garbage are cleaned, the protective support is detached; when the support is dismantled, the jacking support is adjusted firstly to be separated from the existing well top plate frame beam, then the support is dismantled from top to bottom, and the support is moved out of the existing high-voltage cable well.

The invention has the beneficial effects that: the invention can better solve the problem that the lead wire needs to be drilled on the existing high-voltage cable well due to the improvement of the regional power service network by performing waterproof treatment on the interface of the new and old well, and has simple and convenient process and better economic benefit.

Drawings

FIG. 1 is a plan view of a temporary open hole protective structure of a top plate of an operation high-voltage cable well;

FIG. 2 is a sectional view of a temporary hole-opening protection structure of a top plate of an operation high-voltage cable well;

FIG. 3 is an enlarged schematic view of a new and old well interface;

fig. 4 is a construction process flow chart of the temporary hole-opening protection structure for operating the high-voltage cable well top plate.

Description of reference numerals: the novel high-voltage cable well comprises an existing high-voltage cable well 1, an existing well wall 2, an existing well top plate frame beam 3, a newly-built well 4, an excavation side slope 5, a ground drainage ditch 6, a slope bottom drainage ditch 7, a temporary hole 8, an orifice steel plate edge covering 9, an orifice peripheral water retaining ridge 10, a planting bar 11, a groove 12, polyurethane sealing paste 13, a non-woven fabric buffer layer 14, a self-adhesive high-polymer waterproof coiled material 15, a cement nail 16, cement mortar 17, a bowl buckle type support 18, an adjustable top support 19, a dense mesh steel wire mesh 20, waterproof color strip cloth 21, a drain hole 22, a muddy water collecting barrel 23, a high-voltage cable 24, a cable frame 25 and a fireproof blanket 26.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The temporary hole opening protection structure for the top plate of the operation high-voltage cable well and the construction method adopt an open cut method for excavating the existing high-voltage cable well 1, the slopes of the earthwork excavation slopes on two sides are determined according to site conditions, a foundation pit vertical support or a hanging net shotcrete support is adopted as necessary, and a position opening with the minimum influence on the stress structure of the existing well top plate frame beam 3 is selected according to the structure of the existing well top plate frame beam 3, namely the position of the existing well top plate frame beam 3 is avoided, and the temporary hole opening protection structure is arranged along the existing well top plate frame beam 3. After the hole site is determined, according to the structure and the hole site of the existing high-voltage cable well 1, a working well is newly built above the planned opening of the existing well, the well wall of the working well is positioned right above the existing well top plate frame beam 3 or the existing well wall 2, the new well wall is poured by planting ribs on the existing well top plate frame beam 3 or the existing well wall 2, and the outer sides of the interface of the new well and the old well (the outer side of the new well wall and the upper surface of the existing well top plate) are well protected from water. Before the existing well roof plate is perforated, the operating cable in the existing well is protected, then a protection platform is set up under the well mouth, and the phenomenon that perforated concrete slag, cutting muddy water and the like pollute the adjacent high-voltage cable is avoided. Before tapping, a proper method is adopted to accurately position hole positions, then a concrete core drilling machine is adopted to drill holes, a polishing machine is adopted to polish the periphery of an orifice, and finally a steel plate is adopted to carry out edge covering treatment. Concrete water retaining ridges are arranged around the hole openings of the top plate of the existing well, so that accumulated water of a new well is prevented from flowing into the existing high-voltage cable well 1.

As shown in fig. 1-3, the temporary hole-opening protection structure for the top plate of the operation high-voltage cable well comprises an existing high-voltage cable well 1, a well wall 2 of the existing well, a frame beam 3 of the top plate of the existing well, a newly-built well 4, an excavation side slope 5, a ground drainage ditch 6, a slope bottom drainage ditch 7, a temporary hole 8, an orifice steel plate edge 9, an orifice peripheral water retaining ridge 10, a steel bar planting 11, a groove 12, polyurethane sealing paste 13, a non-woven fabric buffer layer 14, a self-adhesive high-molecular waterproof coiled material 15, cement nails 16, cement mortar 17, a bowl buckle type support 18, an adjustable top support 19, a dense mesh steel wire mesh 20, waterproof color strip cloth 21, a drainage hole 22, a muddy water collecting barrel 23, a high-voltage cable 24, a cable frame 25. A temporary hole 8 is arranged on the top plate of the existing high-voltage cable well 1 to be used as an inlet and an outlet of the high-voltage cable. Excavating the earth covering of the existing high-voltage cable well, determining an excavated side slope 5 and a corresponding net hanging injection protection measure according to the buried depth and the earth covering, and respectively arranging a ground drainage ditch 6 and a slope bottom drainage ditch 7 on the original ground and the slope bottom; according to the structure of the existing shaft roof plate frame beam 3, the position opening which has the minimum influence on the stress structure of the roof plate frame beam is selected, the position of the roof plate frame beam is avoided, the temporary hole 8 is formed along the existing shaft roof plate frame beam 3, the temporary hole 8 is provided with an orifice steel plate wrapping edge 9, and an orifice peripheral water retaining ridge 10 is arranged around the orifice to prevent roof water from flowing into the existing high-voltage cable well 1 through the temporary hole 8. Before the temporary hole 8 is drilled, a new well 4 is poured on an existing high-voltage cable well 1, the well wall of the new well is located on the well wall 2 of the existing well or a frame beam 3 of an existing well top plate, a new well structure and an old well structure are connected into a whole through embedded steel bars 11, water is prevented outside the interface of the new well and the old well (the outer side of the well wall of the new well and the upper surface of the existing well top plate), a groove 12 is reserved on the well wall of the new well 4, during the water prevention construction of the interface of the new well and the old well, a 100g/m2 non-woven fabric buffer layer 14 is firstly paved, then a 2.0-thick self-adhesive high polymer waterproof coiled material 15 is paved, a cement nail 16 is adopted to fix the contraction of the well wall of the new well, a polyurethane sealing paste 13 is.

Before the temporary hole 8 is opened, a bowl buckle type support 18 is erected below the existing shaft top plate frame beam 3, the support vertical rod is erected on a bottom plate inside the existing high-voltage cable shaft 1, an adjustable jacking 19 is arranged on the upper portion of the vertical rod, a dense mesh steel wire mesh 20 is laid on the adjustable jacking 19, waterproof color strip cloth 21 is laid on the dense mesh steel wire mesh 20, a drain hole 22 is arranged at the lowest position in the middle of the waterproof color strip cloth 21, and construction muddy water is drained into a muddy water collecting barrel 23 through the drain hole 22. The support is adjusted around to jack the existing well roof frame beam 3 tightly without gaps. Meanwhile, before the hole is opened, the high-voltage cable 24 in the existing high-voltage cable well 1 is covered by a double-layer fireproof blanket 26 for protection.

As shown in fig. 4, the construction method for operating the temporary open hole protective structure of the high-voltage cable well roof comprises the following steps:

step one, determining the hole position of the top plate of the existing cable well. Look up 1 completion drawings of existing high-voltage cable well, know 1 structural arrangement of existing high-voltage cable well, according to 3 structures of existing well roof plate frame roof beam, select the position opening that influences 3 bearing structure minimum of existing well roof plate frame roof beam, avoid 3 positions of existing well roof plate frame roof beam promptly, set up the hole site along existing well roof plate frame roof beam 3 to carry out 4 structural design of newly-built well. The wall of the newly-built well is required to be positioned right above the existing well top plate frame beam 3 or the existing well wall 2, the newly-built well wall is poured by planting ribs on the existing well top plate frame beam 3 or the existing well wall 2, the wall of the newly-built well is required to meet the shearing resisting effect of earthwork backfilling, and the waterproof performance of the interface between the newly-built well and the old well (the outer side of the newly-built well wall and the upper surface of the existing well top plate) is well achieved.

Step two, earth covering and excavating of the existing cable well. After the hole site of the existing well roof is determined, the existing high-voltage cable well 1 is measured and lofted on site, and the slope grade of slope release and the net hanging injection support are determined according to the buried depth, the soil quality and the site conditions. And firstly, the constructor at the project department rechecks the set axis again according to the engineering positioning point, and measures and lofts the pile position according to the axis positioning. During mechanical excavation, the existing high-voltage cable well 1 position is avoided at the mechanical parking position, construction scheme, technology, quality, safety and environmental protection are carried out on earth construction teams and constructors before earth excavation, specially-assigned persons command and strictly forbid over excavation, and an underground supporting member is required to be provided with an obvious identifier and is forbidden to be damaged and destroyed. And before the height of the existing well roof is 30cm, manual excavation is adopted. After the foundation pit is excavated, a 120-thick M15 brick-built ground drainage ditch 6 (30 cm in width and 40cm in depth) is arranged at the position of no less than 50cm outside the top of the slope, a 120-thick M15 brick-built slope bottom drainage ditch 7 (30 cm in width and 40cm in depth) is also arranged at the position of the slope foot, and the horizontal distance from the wall of the newly-built well is required to be no less than 80cm, so that rainwater is prevented from flowing into the foundation pit, and the slope is stable and does not collapse.

And step three, pouring the new well. The wall of the newly built well is positioned above the frame beam 3 of the existing well top plate or the wall 2 of the existing well. Double-layer steel bars are planted on the frame beam 3 of the existing well top plate or the existing well wall 2, so that the well wall of the newly-built well and the existing high-voltage cable well 1 are subjected to consolidation pouring. The embedded bars 11 are required to be embedded into the existing well top plate frame beam 3 or the existing well wall 2 at least 20cm and at intervals of 20 cm. And then, a steel reinforcement framework is lengthened on the embedded steel bars 11, and the new well 4 is poured.

And step four, protecting the existing high-voltage operation cable. After the newly-built well is poured, the high-voltage cable operated in the existing well is protected according to the hole positions, the double-layer fireproof blanket 26 is covered, and the phenomenon that the cable protection layer is damaged due to the falling of hole opening sparks or concrete residues is avoided, so that disasters are caused.

And step five, setting up the protective support under the existing well hole. Before the hole is opened, a closed protective platform under the temporary hole 8 is firstly erected, so that the falling of wastes such as sparks or concrete slag blocks and muddy water during the hole opening is prevented, and the inner structure of the existing high-voltage cable well 1 is prevented from being polluted. The protective platform is erected by adopting a phi 48x3.5mm steel pipe bowl-buckled support 18, a vertical rod of the bowl-buckled support 18 is erected on a bottom plate in the existing high-voltage cable well 1, and an adjustable jacking 19 is arranged at the upper part of the vertical rod and used for height adjustment. A dense mesh steel wire mesh 20 is laid on the adjustable jacking 19, waterproof color stripe cloth 21 is laid on the dense mesh steel wire mesh 20, and the jacking is adjusted around the vertical rod to tightly jack the existing well roof plate frame beam 3 without gaps. The jacking is adjusted to ensure that the periphery is high and the middle is low, then a drain hole 22 is arranged at the lowest position in the middle of the waterproof color stripe cloth 21, and muddy water is led into a muddy water collecting barrel 23 through a hose for centralized treatment. The dense mesh steel wire mesh 20 can prevent the top plate chiseled concrete from falling into the existing high-voltage cable shaft 1. The distance between the cross bars of the existing high-voltage cable well 1 is 1.5x1.0m, the step pitch is 1.8m, the length of the vertical rod is determined according to the height of the existing high-voltage cable well 1, and the setting length and the width of the platform are respectively 2m larger than the size of the temporary hole 8.

And step six, opening holes and processing orifices. Along 3 trompils of existing well head board frame roof beam, the trompil process need be paid attention to and avoid causing the damage to existing well head board frame roof beam 3, and accurate positioning is very crucial. Because the position of the frame beam 3 of the existing well roof plate cannot be directly projected to the roof plate for marking, measures are actually required to be taken for hole site lofting. Firstly, marking a theoretical position on a well top according to the structural size of the frame beam 3 of the existing well top plate, then drilling through the top plate along the position of the theoretical side line of the frame beam 3 of the existing well top plate at four angles with enough safety, calculating the edge line of the frame beam 3 of the existing well top plate according to the distance between a hole position in the top plate and the edge of the frame beam 3 of the existing well top plate, and popping up a hole position cutting ink line. Then a concrete pavement joint cutter is used for cutting a joint to a depth of 30mm, and after the joint is cut, holes are taken along the inner side of the joint by a concrete core taking machine, wherein the diameter of each hole is 50mm, and the distance between every two holes is 100 mm. And after the hole is taken, the air pick is used for removing the top plate in a blocking mode, and when the top plate meets steel bars, the angle polishing machine is used for cutting the top plate. The large concrete slag is crushed and then the broken blocks are manually and timely transported.

And after the hole of the top plate is drilled, trimming the periphery of the hole surface, and adhering a steel plate edge by using pressure epoxy resin adhesive. Meanwhile, in order to prevent accumulated water in the newly built well 4 from flowing into the existing high-voltage cable well 1 through the orifice, the orifice peripheral water retaining ridge 10 is arranged along the peripheral outer side of the orifice.

And step seven, performing waterproof treatment on the interfaces of the new well and the old well. Because the new well and the old well are all positioned underground, waterproof treatment is well performed outside the interface of the new well and the old well (the outer side of the well wall of the newly-built well and the upper surface of the existing well top plate). The waterproof method comprises the following steps: when the wall of a newly-built well is poured, a groove 12 with the height of 50mm multiplied by 60mm is reserved on the wall of the well with the height of 40cm from the top plate of the existing well; after the well wall of the newly-built well is poured, the new and old well interface waterproof construction is carried out, and 100g/m of waterproof construction is firstly paved²A non-woven fabric buffer layer 14, then a self-adhesive high-molecular waterproof coiled material 15 with the thickness of 2.0 is paved, a cement nail 16 is adopted to fix the well wall contraction of the newly-built well, a polyurethane sealant 13 is filled in the groove 12, and cement mortar 17 with the thickness of 20: 2.5 is paved on the outer layer.

And step eight, dismantling protective measures. And (4) finishing the hole opening edge covering and the water retaining ridge treatment, and removing the protective bracket after finishing the cleaning of the wastes such as concrete slag, muddy water and the like. When the support is dismantled, the jacking support is adjusted firstly to be separated from the frame beam 3 of the existing well top plate, then the support is dismantled from top to bottom, and the support is manually moved out of the existing high-voltage cable well.