CN108842819B - Urban rail transit cable line tunnel construction method - Google Patents
Urban rail transit cable line tunnel construction method Download PDFInfo
- Publication number
- CN108842819B CN108842819B CN201811044177.6A CN201811044177A CN108842819B CN 108842819 B CN108842819 B CN 108842819B CN 201811044177 A CN201811044177 A CN 201811044177A CN 108842819 B CN108842819 B CN 108842819B
- Authority
- CN
- China
- Prior art keywords
- steel
- pile
- construction
- foundation pit
- support
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/10—Tunnels or galleries specially adapted to house conduits, e.g. oil pipe-lines, sewer pipes ; Making conduits in situ, e.g. of concrete ; Casings, i.e. manhole shafts, access or inspection chambers or coverings of boreholes or narrow wells
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/16—Arrangement or construction of joints in foundation structures
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D31/00—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
- E02D31/02—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution against ground humidity or ground water
- E02D31/025—Draining membranes, sheets or fabric specially adapted therefor, e.g. with dimples
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Civil Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Hydrology & Water Resources (AREA)
- Lining And Supports For Tunnels (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention discloses a construction method of an urban rail transit cable line tunnel, which comprises the following steps: step S1, measuring and paying off; step S2, constructing the fender post; step S3, mounting a steel support; step S4, earth excavation; step S5, construction of a bottom plate structure: constructing the tunnel structure by adopting a segmentation method; continuously constructing a steel plate pile section and a cast-in-place pile, and constructing a cast-in-place pile section structure after the cast-in-place pile section reaches the strength; s6, dismantling the steel support; step S7, construction joint processing; step S8, constructing side wall and top plate structures; and step S9, backfilling the lateral and top plate earthwork. The invention adopts the integrated foundation pit supporting technology of combining the enclosure structure steel sheet pile with the cast-in-place pile construction, and the enclosure piles are driven into the foundation to be connected with each other to form a whole, thereby reducing the construction cost, reducing the environmental damage and improving the construction efficiency; through the upper and lower two steel supports, adopt I-steel and add the welding through-length steel sheet and batten plate and the floor connection becomes a atress whole, improves the safety and stability of supporting the system.
Description
Technical Field
The invention belongs to the technical field of cable line construction, and particularly relates to a tunnel construction method for cable lines of urban rail transit.
Background
In recent years, with the doubled and enlarged urban scale of China, the problem of backward infrastructure appears, and the contradiction between urban transportation and transportation is increasingly prominent. The urban rail transit has the advantages of safety, punctuality and rapidness, and plays an increasingly important role in widening urban space, building an urban rapid three-dimensional traffic network and improving urban traffic environment. According to the requirements of urban sustainable development and urban traffic healthy development, urban rail transit projects are actively planned and constructed in all big cities in the country, urban rail transit transmission and transformation lines inherit the characteristics of subway construction, the occupied ground space is reduced as little as possible, and the influence on urban development is reduced, so that the underground cable tunnel saves space, the cable laying mode with better safety performance is widely used, but the requirement for higher protection of cable tunnel construction excavation is continuously met by construction to a deeper underground part.
Disclosure of Invention
The invention aims to provide a construction method of an urban rail transit cable line tunnel, which is characterized in that the construction quality and efficiency are improved while the safe construction is ensured by arranging an integrated foundation pit supporting technology of construction of an enclosure structure steel sheet pile and a cast-in-place pile.
The purpose of the invention can be realized by the following technical scheme:
a construction method of an urban rail transit cable line tunnel comprises the following steps:
step S1, measuring and setting line
1) Measuring and releasing a control pile on the leveled working surface;
2) measuring and placing the central line of the foundation pit fender pile and the position of the drainage ditch; according to the three on-site reference control piles, temporary control piles of the foundation pit fender piles are measured and released at the periphery of the site by using a theodolite, a total station and a level gauge;
3) setting temporary control piles according to construction requirements;
step S2, fender post construction
The types of foundation pit support are respectively adopted as follows:
supporting with steel sheet piles: when the excavation depth of the foundation pit is less than or equal to 6.0m, and no building exists at the periphery and a construction surface far away from a road is constructed, a Larsen IV-shaped steel plate pile and two steel support supports are adopted for supporting;
and (3) supporting the cast-in-situ bored pile: when the depth of the foundation pit is more than 6.0m, or buildings exist at the periphery, or the foundation pit is close to a road, a cast-in-situ bored pile with the diameter of 0.6m and two steel support supports are adopted; correspondingly prolonging the length of the supporting pile according to the excavation depth of the foundation pit, and ensuring that the anchoring depth of the pile body into the substrate is not less than 2.0 m;
1) construction of steel sheet pile
(1) Steel sheet pile for inspection and correction
Carrying out appearance inspection and material inspection on the steel sheet piles entering the field;
(2) piling steel sheet pile
The method is characterized in that a special self-vibrating mechanical inserting and driving method for the steel sheet piles is adopted, and holes are firstly led and then the steel sheet piles are driven for areas with hard soil;
2) cast-in-situ bored pile construction
After the drilling machine is in place, pile jumping construction is adopted, and drilling is carried out within 3 days after concrete pouring within the range of 3 times of the pile diameter; monitoring center position deviation, drilling depth, rotating rod verticality and oil pressure change in the drilling process, stopping drilling and timely lifting a drill rod when underground obstacles or hole collapse and underground water conditions are met, and continuing operation after checking treatment; after drilling and hole cleaning are finished, timely placing a reinforcement cage and pouring concrete;
step S3, mounting a steel support:
according to the earth excavation depth, adopting phi 609x16/12 steel pipe steel support to complete two-way erection in time;
steel sheet piling: excavating a foundation pit in a longitudinal sectional manner, and installing a first steel support when the excavation depth reaches 0.5 m below the design elevation of the first steel support; when the depth of the excavation foundation pit reaches 0.5 m below the design elevation of the second steel support, mounting the second steel support;
pile grouting: after the concrete strength of the cast-in-place pile and the crown beam reaches 100% of the designed strength, installing a first steel support when excavating the foundation pit longitudinally and sectionally to a position 0.5 m below the elevation of the bottom of the crown beam; when the foundation pit is excavated longitudinally and sectionally to a position 0.5 m below the design elevation of the second steel support, the second steel support is installed; the first steel support is directly supported on the crown beam, and the second steel support is arranged at the position of the steel purlin;
step S4, earth excavation
1) Foundation pit monitoring
Monitoring points are reasonably arranged on the deformation of a foundation pit supporting system, peripheral buildings and important pipelines, the settlement and displacement of the top of the foundation pit and underground water level projects before earth excavation, and the stable condition of the foundation pit is monitored and known in real time;
2) excavation of foundation pit earthwork
The excavation construction of the lower-layer earthwork can be carried out only after the excavation of each layer of earthwork is finished and the steel supports are erected by the enclosure structure formed by the cast-in-situ bored piles, the steel sheet piles and the steel supports; in the process of earth excavation, the statistical analysis of monitoring and measuring is enhanced, and the deformation displacement of a supporting structure and the uneven settlement of a soil body are monitored in real time;
step S5, construction of a bottom plate structure:
constructing the tunnel structure by adopting a segmentation method; continuously constructing a steel plate pile section and a cast-in-place pile, constructing an earth excavation structure after the support construction of the steel plate pile section is completed, and constructing a cast-in-place pile section structure after the cast-in-place pile section reaches the strength;
step S6, steel support dismantling
1) The steel support is dismantled, the support stress is released, and the loose ends are loosened to dismantle the disc one by one;
2) dismantling steel supports and cast-in-place piles of the steel sheet piles: after the concrete of the bottom plate and the side wall reaches 100% of the design strength, the second steel support can be disassembled, and after the concrete strength of the main structure of the tunnel reaches 100% of the design strength, the first steel support can be disassembled; after the steel support is dismantled, the steel sheet pile is pulled out, and before the steel sheet pile is pulled out, the surrounding environment is carefully observed, and corresponding measures are taken to reduce the damage to the surrounding environment; the pile pulling sequence is opposite to the pile driving sequence; after the pile body is pulled out, the pile hole is timely backfilled with graded sandstone; the steel sheet pile is pulled out by a vibration hammer and a crane together;
step S7, construction joint processing
The horizontal construction joints of the wall are left on the wall which is not less than 300mm higher than the surface of the bottom plate; before the horizontal construction joint is used for casting concrete, removing floating slurry and sundries on the surface of the horizontal construction joint, then paving clean slurry or brushing materials such as a concrete interface treating agent, a cement-based permeable crystallization type waterproof coating and the like, paving 1:1 cement mortar with the thickness of 30-50mm, and casting the concrete in time;
step S8, construction of side wall and top plate structure
Performing waterproof construction on the side wall and the top plate;
step S9, lateral and roof earthwork backfilling
Backfilling and tamping the backfill soil layer by layer according to the design requirement; in the filling and tamping process, the filler is filled and tamped layer by layer, and the compaction times of each layer are 3-4 times, so that the construction is completed.
Further, the steel sheet pile appearance inspection in step S2 includes: the steel sheet pile which does not meet the shape requirement is corrected by the contents of surface defects, length, width, height, thickness, end rectangle ratio, flatness, locking notch shape and the like so as to reduce the piling difficulty and pile position deviation; the steel sheet pile correction comprises surface defect repair, end plane correction, pile body deflection and distortion correction, pile body local deformation correction and locking notch deformation correction.
Further, the concrete step of driving the steel sheet pile in step S2 is as follows: before driving the pile, measuring, positioning and paying off the pile, and inserting the pile in place according to the line; when piling, controlling the precision of the driving positions and directions of the first and second steel sheet piles to be driven, and measuring once every 1 m; the allowed error of the printing is as follows: the pile top elevation deviation is +/-100 mm, the steel sheet pile axis deviation is +/-100 mm, and the steel sheet pile verticality deviation is 1%; and monitoring whether the deviation is within an allowable range in time, and correcting in time when the deviation exceeds the allowable range.
Further, in the step S2, the hole cleaning manner is to clean the hole by using a flat-bottom double-door type hole cleaning drill.
Further, in the step S3, the first steel support frame is directly placed on the first wale beam, and the second steel support frame is placed on the steel purlin; the steel enclosing purlin is welded with common double-spliced 45b steel plates by adopting 20mm Q235 steel plates, the I-shaped steel is formed by welding through long steel plates, batten plates and rib plates to form a stressed whole, the steel enclosing purlin is supported by an angle steel bracket fixed on the enclosing pile, and the steel enclosing purlin and the steel support are erected by manually matching lifting equipment; the steel support frame pre-stressed axial force adopts a hydraulic jack; the support is assembled outside the foundation pit, and the lifting equipment lifts by crane the whole installation.
Further, the concrete steps of monitoring the foundation pit in step S4 are as follows:
(1) observing and monitoring the surface settlement: burying ground surface settlement points on the hardened ground outside the foundation pit; drilling a hole on the ground by using a percussion drill or a spiral drilling machine until the hole is 100-200 mm in diameter and deep until the hardened concrete is broken through, then driving a threaded round-head steel bar with the length of 1000-1500 mm and the diameter of 16mm into the hole, and filling the periphery with standard sand; arranging more than 3 stable elevation datum points at positions far away from the construction influence range, and forming a leveling network for joint measurement by using the stable elevation datum points as starting points for surface settlement;
(2) monitoring the axial force of the steel support: when the steel support is erected, the mounting frame is vertically welded on the fixed end of the support, the center of the mounting frame and the center of the support are ensured to be on the same straight line during welding, and then the axial force meter is stably arranged in the mounting frame; testing the axial pressure of the support by adopting an axial force meter;
(3) water level monitoring: when water level holes outside the foundation pit are arranged, after a drilling machine is used for drilling to the depth required by design, water filtering plastic sleeves with the pipe diameter of 50mm are embedded in the holes; the depth from the water surface to the pipe orifice is directly read by adopting a water level meter, and the water level elevation is determined by subtracting the water surface depth from the pipe orifice elevation, so that the underground water level is monitored.
Further, the construction by the segmentation method in step S5 specifically includes: 1) and (3) steel bar engineering: the overlapping length, the joint mode and the joint position of the binding joint meet the requirements of design and regulations; 2) the installation of the template and the bracket thereof must be carried out strictly by the construction technical scheme, and the joint of the template should not leak slurry; 3) the waterproof concrete is preferably premixed commercial concrete, and the slump in the pump is controlled to be 160 mm; the concrete should be continuously poured, and construction joints should be kept small.
Further, in the step S6, the stress is released by placing 2 hydraulic jacks of 30 tons into the loose end, and the jacks are ensured to have consistent jacking force, the two jacks are fixed into a whole by manufacturing special brackets, the pump is started to apply prestress after the oil pipe is connected, the steel wedge block in the loose end is taken out in time after the prestress is applied in place, and the steel wedge block is slowly put down after the connection is removed.
Further, the specific method of waterproof construction in step S8 is: the waterproof concrete for the side wall and the top plate is prepared by adjusting the mixing proportion or adding an additive and an admixture, and the anti-permeability grade of the waterproof concrete is not less than P6; the structural waterproofing adopts a mode of combining concrete structural self waterproofing with a waterproof coiled material; the deformation joints of the top plate and the wall plate adopt a middle-buried steel-edged rubber water stop, 30mm thick polyethylene low-foaming joint filling and 30-by-30 two-component polysulfide sealant caulking.
The invention has the beneficial effects that:
(1) the invention adopts the integrated foundation pit supporting technology of combining the enclosure structure steel sheet pile with the cast-in-place pile construction, and the enclosure pile is driven (pressed) into the foundation by the pile driver, so that the enclosure pile and the foundation are connected with each other to form a whole, thereby reducing the construction cost, reducing the environmental damage and improving the construction efficiency;
(2) the invention adopts the dispersed stress strong support, supports through an upper steel and a lower steel, simultaneously adopts I-shaped steel and welds a through long steel plate, a batten plate and a rib plate to connect the steel plates into a stressed whole, avoids the stress concentration of a single support and improves the safety and stability of a support system;
(3) the construction method is characterized in that pre-layout is carried out on the construction position of the steel sheet pile to reserve the construction joint, a size control point and a construction procedure are determined before construction, fine management is carried out strictly according to the construction procedure, and the deviation of the construction joint is effectively controlled;
(4) the method is sequentially constructed based on the main structures which are completely connected in the process, so that the energy is saved and the efficiency is high;
(5) the tunnel main body structure is constructed by adopting a segmentation method, so that the construction period can be effectively shortened.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A construction method of an urban rail transit cable line tunnel comprises the following steps:
step S1, measuring and setting line
1) And measuring and releasing the control pile on the leveled working surface. According to the control coordinate and elevation position in the field provided by design investigation, measuring and placing a coordinate and elevation control pile disc;
2) measuring and placing the central line, the drainage ditch and other positions of the foundation pit fender pile according to the requirements of a construction drawing; according to the three on-site reference control piles, temporary control piles of the foundation pit fender pile are measured and released at the periphery of the site by using a theodolite, a total station, a level gauge and the like;
3) setting temporary control piles according to construction requirements;
step S2, fender post construction
The method integrates the aspects of engineering geology, hydrogeology conditions, economy and the like, combines factors such as difficulty in digging and slope setting and the like, and adopts the following types of foundation pit support respectively:
supporting with steel sheet piles: according to a design drawing, when the excavation depth of the foundation pit is less than or equal to 6.0m, and no building and a construction surface far away from a road exist at the periphery, adopting Larsen IV-type steel sheet piles and two steel support supports for supporting;
and (3) supporting the cast-in-situ bored pile: when the depth of the foundation pit is more than 6.0m, or buildings exist at the periphery, or the foundation pit is close to a road, a cast-in-situ bored pile with the diameter of 0.6m and two steel support supports are adopted for supporting. Correspondingly prolonging the length of the supporting pile according to the excavation depth of the foundation pit, and ensuring that the anchoring depth of the pile body into the substrate is not less than 2.0 m;
1) construction of steel sheet pile
(1) Steel sheet pile for inspection and correction
Carrying out appearance inspection and material inspection on the steel sheet piles entering the field; the steel sheet pile appearance inspection comprises the following steps: the steel sheet pile which does not meet the shape requirement is corrected by the contents of surface defects, length, width, height, thickness, end rectangle ratio, flatness, locking notch shape and the like so as to reduce the piling difficulty and pile position deviation; the steel sheet pile correction comprises surface defect repair, end plane correction, pile body deflection and distortion correction, pile body local deformation correction, locking notch deformation correction and the like;
(2) piling steel sheet pile
The method is characterized in that a special self-vibrating mechanical inserting and driving method for the steel sheet pile is adopted, holes are firstly led and then the steel sheet pile is driven for a hard soil area, specifically, before the pile is driven, the measurement positioning and paying-off are carried out, and the pile is inserted in place according to the line; when piling, controlling the precision of the driving positions and directions of the first and second steel sheet piles to be driven, and measuring once every 1 m; the allowed error of the printing is as follows: the pile top elevation deviation is +/-100 mm, the steel sheet pile axis deviation is +/-100 mm, and the steel sheet pile verticality deviation is 1%; monitoring whether the deviation is within an allowable range in time, and correcting in time when the deviation exceeds the allowable range;
2) cast-in-situ bored pile construction
After the drilling machine is in place, pile jumping construction is adopted, and drilling is carried out within 3 days after concrete pouring within the range of 3 times of the pile diameter; in the drilling process, central position deviation, drilling depth, rotating rod verticality, oil pressure change (corresponding to rock strength) and the like are monitored, when underground obstacles or hole collapse, underground water and the like are met, drilling is stopped, a drill rod is lifted in time, and operation can be continued after inspection and treatment; after drilling and hole cleaning are finished, timely placing a reinforcement cage and pouring concrete; the hole cleaning mode adopts a flat bottom double-door type hole cleaning drill bit to clean holes;
step S3, mounting a steel support:
according to the requirements of a drawing, adopting phi 609x16/12 steel pipe steel support to complete 2-way erection in time according to the earth excavation depth;
steel sheet piling: excavating a foundation pit in a longitudinal sectional manner, and installing a first steel support when the excavation depth reaches 0.5 m below the design elevation of the first steel support; when the depth of the excavation foundation pit reaches 0.5 m below the design elevation of the second steel support, mounting the second steel support;
the first steel support frame is directly arranged on the first waist beam, and the second steel support frame is arranged on the steel purlin; the steel enclosing purlin is welded with common double-spliced 45b steel plates by adopting 20mm Q235 steel plates, the I-shaped steel is formed by welding through long steel plates, batten plates and rib plates to form a stressed whole, the steel enclosing purlin is supported by an angle steel bracket fixed on the enclosing pile, and the steel enclosing purlin and the steel support are erected by manually matching lifting equipment; the steel support frame pre-stressed axial force adopts a hydraulic jack; the support is assembled outside the foundation pit, and the lifting equipment lifts the whole foundation pit for installation;
pile grouting: after the concrete strength of the cast-in-place pile and the crown beam reaches 100% of the designed strength, installing a first steel support when excavating the foundation pit longitudinally and sectionally to a position 0.5 m below the elevation of the bottom of the crown beam; when the foundation pit is excavated longitudinally and sectionally to a position 0.5 m below the design elevation of the second steel support, the second steel support is installed; the first steel support is directly supported on the crown beam, and the second steel support is arranged at the position of the steel purlin;
step S4, earth excavation
1) Foundation pit monitoring
Monitoring points are reasonably arranged on items such as deformation of a foundation pit supporting system, peripheral buildings (structures), deformation observation of important pipelines, settlement of the top of the foundation pit, displacement, underground water level and the like before earth excavation according to design drawings and standard requirements, and the stable condition of the foundation pit is monitored and known in real time;
(1) observing and monitoring the surface settlement: burying ground surface settlement points on the hardened ground outside the foundation pit; drilling a hole on the ground by using a percussion drill or a spiral drilling machine until the hole is 100-200 mm in diameter and deep until the hardened concrete is broken through, then driving a threaded round-head steel bar with the length of 1000-1500 mm and the diameter of 16mm into the hole, and filling the periphery with standard sand; arranging more than 3 stable elevation datum points at positions far away from the construction influence range, and forming a leveling network for joint measurement by using the stable elevation datum points as starting points for surface settlement;
(2) monitoring the axial force of the steel support: when the steel support is erected, the mounting frame is vertically welded on the fixed end of the support, the center of the mounting frame and the center of the support are ensured to be on the same straight line during welding, and then the axial force meter is stably arranged in the mounting frame; testing the axial pressure of the support by adopting an axial force meter;
(3) water level monitoring: when water level holes outside the foundation pit are arranged, after a drilling machine is used for drilling to the depth required by design, water filtering plastic sleeves with the pipe diameter of 50mm are embedded in the holes; directly reading the depth from the water surface to the pipe orifice by adopting a water level meter, and subtracting the water surface depth from the height of the pipe orifice to determine the water level height so as to monitor the underground water level;
2) excavation of foundation pit earthwork
The excavation of the foundation pit follows the principle of 'from top to bottom, firstly supporting and then excavating, excavating in layers and strictly forbidding over-excavation', a surrounding structure formed by the cast-in-situ bored piles, the steel sheet piles and the steel supports can only carry out excavation construction of the lower-layer earthwork after the excavation of each layer of earthwork is finished and the steel supports are erected; in the process of earth excavation, the statistical analysis of monitoring and measuring is enhanced, and the deformation displacement of a supporting structure and the uneven settlement of a soil body are monitored in real time;
step S5, construction of a bottom plate structure:
the tunnel structure is constructed by a segmentation method, taking a 35kV cable tunnel integrated by a combined fertilizer rail transit No. 2 line 110kV main substation system as an example, the whole length of the tunnel is 1.65km, the position of the cable tunnel structure is positioned in a green belt at the side of a municipal road, surrounding structures are dense, and underground pipelines are complex; dividing 17 working sections according to the site construction conditions on the whole line, as shown in the following table 1; continuously constructing a steel plate pile section and a cast-in-place pile, constructing an earth excavation structure after the support construction of the steel plate pile section is completed, and constructing a cast-in-place pile section structure after the cast-in-place pile section reaches the strength;
1) and (3) steel bar engineering: the overlapping length, the joint mode and the joint position of the binding joint meet the requirements of design and regulations;
2) the installation of the template and the bracket thereof must be carried out strictly by the construction technical scheme, and the joint of the template should not leak slurry;
3) the waterproof concrete is preferably premixed commercial concrete, and the slump in the pump is controlled to be 160 mm; the concrete should be continuously poured, and construction joints should be kept less;
step S6, steel support dismantling
The steel support is dismantled, the support stress is released, and the loose ends are loosened to dismantle the disc one by one; 2 hydraulic jacks of 30 tons are placed into the adjustable end to support and release stress, the jacking force of the jacks is ensured to be consistent, the two jacks are fixed into a whole by special brackets, a pump is started to apply prestress after an oil pipe is connected, a steel wedge block in the adjustable end is taken out in time after the prestress is applied in place, and the steel wedge block is slowly put down after the connection is removed;
dismantling a steel sheet pile steel support: according to the requirements of design drawings, after the concrete of the bottom plate and the side wall reaches 100% of the design strength, the second steel support can be disassembled, and after the concrete strength of the main structure of the tunnel reaches 100% of the design strength, the first steel support can be disassembled; after the steel support is dismantled, the steel sheet pile is pulled out, and before the steel sheet pile is pulled out, the surrounding environment needs to be carefully observed, and corresponding measures are taken to reduce the damage to the surrounding environment; the pile pulling sequence is generally opposite to the pile driving sequence; after the pile body is pulled out, the pile hole is timely backfilled with graded sandstone; the steel sheet pile is pulled out by a vibration hammer and a crane together;
supporting a cast-in-place pile: the steel sheet pile is consistent with the steel sheet pile steel support in dismounting;
step S7, construction joint processing
The horizontal construction joint of the wall body is not left at the position with the maximum shearing force or the joint of the bottom plate and the side wall and is left on the wall body which is not less than 300mm higher than the surface of the bottom plate; before the horizontal construction joint is used for casting concrete, removing floating slurry and sundries on the surface of the horizontal construction joint, then paving clean slurry or brushing materials such as a concrete interface treating agent, a cement-based permeable crystallization type waterproof coating and the like, paving 1:1 cement mortar with the thickness of 30-50mm, and casting the concrete in time;
step S8, construction of side wall and top plate structure
The waterproof concrete for the side wall and the top plate is prepared by adjusting the mixing proportion or adding additives, admixtures and other measures, and the anti-permeability grade of the waterproof concrete is not less than P6; the structural waterproofing adopts a mode of combining concrete structural self waterproofing with a waterproof coiled material; the deformation joints of the top plate and the wall plate adopt a middle-buried steel-edged rubber water stop, 30mm thick polyethylene low-foaming joint filling and 30-by-30 two-component polysulfide sealant caulking;
step S9, lateral and roof earthwork backfilling
Backfilling and tamping the backfill soil layer by layer according to the design requirement; in the filling and tamping process, the filler is filled and tamped layer by layer, and the compaction times of each layer are 3-4 times, so that the construction is completed.
The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims (3)
1. A construction method of an urban rail transit cable line tunnel is characterized by comprising the following steps:
step S1, measuring and setting line
1) Measuring and releasing a control pile on the leveled working surface;
2) measuring and placing the central line of the foundation pit fender pile and the position of the drainage ditch; according to the three on-site reference control piles, temporary control piles of the foundation pit fender piles are measured and released at the periphery of the site by using a theodolite, a total station and a level gauge;
3) setting temporary control piles according to construction requirements;
step S2, fender post construction
The types of foundation pit support are respectively adopted as follows:
supporting with steel sheet piles: when the excavation depth of the foundation pit is less than or equal to 6.0m, and no building exists at the periphery and a construction surface far away from a road is constructed, a Larsen IV-shaped steel plate pile and two steel support supports are adopted for supporting;
and (3) supporting the cast-in-situ bored pile: when the depth of the foundation pit is more than 6.0m, or buildings exist at the periphery, or the foundation pit is close to a road, a cast-in-situ bored pile with the diameter of 0.6m and two steel support supports are adopted; correspondingly prolonging the length of the fender post according to the excavation depth of the foundation pit, and ensuring that the anchoring depth of the pile body into the substrate is not less than 2.0 m;
1) construction of steel sheet pile
(1) Steel sheet pile for inspection and correction
Carrying out appearance inspection and material inspection on the steel sheet piles entering the field;
(2) piling steel sheet pile
The method is characterized in that a special self-vibrating mechanical inserting and driving method for the steel sheet piles is adopted, and holes are firstly led and then the steel sheet piles are driven for areas with hard soil;
the concrete steps of driving the steel sheet pile are as follows: before driving the pile, measuring, positioning and paying off the pile, and inserting the pile in place according to the line; when piling, controlling the precision of the driving positions and directions of the first and second steel sheet piles to be driven, and measuring once every 1 m; the allowed error of the printing is as follows: the pile top elevation deviation is +/-100 mm, the steel sheet pile axis deviation is +/-100 mm, and the steel sheet pile verticality deviation is 1%; monitoring whether the deviation is within an allowable range in time, and correcting in time when the deviation exceeds the allowable range;
2) cast-in-situ bored pile construction
After the drilling machine is in place, pile jumping construction is adopted, and drilling is carried out within 3 days after concrete pouring within the range of 3 times of the pile diameter; monitoring center position deviation, drilling depth, rotating rod verticality and oil pressure change in the drilling process, stopping drilling and timely lifting a drill rod when underground obstacles or hole collapse and underground water conditions are met, and continuing operation after checking treatment; after drilling and hole cleaning are finished, timely placing a reinforcement cage and pouring concrete;
step S3, mounting a steel support:
according to the earth excavation depth, adopting phi 609x16/12 steel pipe steel support to complete two-way erection in time;
steel sheet piling: excavating a foundation pit in a longitudinal sectional manner, and installing a first steel support when the excavation depth reaches 0.5 m below the design elevation of the first steel support; when the depth of the excavation foundation pit reaches 0.5 m below the design elevation of the second steel support, mounting the second steel support;
pile grouting: after the concrete strength of the cast-in-place pile and the crown beam reaches 100% of the designed strength, installing a first steel support when excavating the foundation pit longitudinally and sectionally to a position 0.5 m below the elevation of the bottom of the crown beam; when the foundation pit is excavated longitudinally and sectionally to a position 0.5 m below the design elevation of the second steel support, the second steel support is installed; the first steel support is directly supported on the crown beam, and the second steel support is arranged at the position of the steel purlin;
the first steel support is erected and arranged on the first waist beam, and the second steel support is erected and arranged on the steel purlin; the steel enclosing purlin is welded with common double-spliced 45b steel plates by adopting a 20mm Q235 steel plate, the I-shaped steel is formed by welding through long steel plates, batten plates and rib plates to form a stressed whole, the steel enclosing purlin is supported by an angle steel bracket fixed on the enclosing pile, and the steel enclosing purlin and the steel support are erected by adopting manual matching hoisting equipment; the pre-applied axial force of the steel support frame adopts a hydraulic jack; the support is assembled outside the foundation pit, and the lifting equipment lifts the whole foundation pit for installation;
step S4, earth excavation
1) Foundation pit monitoring
Monitoring points are reasonably arranged on the deformation of a foundation pit supporting system, peripheral buildings and important pipelines, the settlement and displacement of the top of the foundation pit and underground water level projects before earth excavation, and the stable condition of the foundation pit is monitored and known in real time;
the concrete steps of foundation pit monitoring are as follows:
(1) observing and monitoring the surface settlement: burying ground surface settlement points on the hardened ground outside the foundation pit; drilling a hole on the ground by using a percussion drill or a spiral drill, wherein the diameter of the hole is 100-200 mm, the depth of the hole is until the hardened concrete is broken through, then driving a threaded round-head reinforcing steel bar with the length of 1000-1500 mm and the diameter of 16mm into the hole, and filling the periphery of the hole with standard sand; arranging more than 3 stable elevation datum points at positions far away from the construction influence range, and forming a leveling network for joint measurement by using the stable elevation datum points as starting points for surface settlement;
(2) monitoring the axial force of the steel support: when the steel support is erected, the mounting frame is vertically welded on the fixed end of the support, the center of the mounting frame and the center of the support are ensured to be on the same straight line during welding, and then the axial force meter is stably arranged in the mounting frame; testing the axial pressure of the support by adopting an axial force meter;
(3) water level monitoring: when water level holes outside the foundation pit are arranged, after a drilling machine is used for drilling to the depth required by design, water filtering plastic sleeves with the pipe diameter of 50mm are embedded in the holes; directly reading the depth from the water surface to the pipe orifice by adopting a water level meter, and subtracting the water surface depth from the height of the pipe orifice to determine the water level height so as to monitor the underground water level;
2) excavation of foundation pit earthwork
The excavation construction of the lower-layer earthwork can be carried out only after the excavation of each layer of earthwork is finished and the steel supports are erected by the enclosure structure formed by the cast-in-situ bored piles, the steel sheet piles and the steel supports; in the process of earth excavation, the statistical analysis of monitoring and measuring is enhanced, and the deformation displacement of a supporting structure and the uneven settlement of a soil body are monitored in real time;
step S5, construction of a bottom plate structure:
constructing the tunnel structure by adopting a segmentation method; continuously constructing a steel plate pile section and a bored pile, performing earth excavation structure construction after the support construction of the steel plate pile section is completed, and performing bored pile section structure construction after the strength of the bored pile section is reached;
the construction by the subsection method comprises the following specific steps: 1) and (3) steel bar engineering: the overlapping length, the joint mode and the joint position of the binding joint need to meet the requirements of design and regulations; 2) the installation of the template and the support thereof must be strictly carried out according to the installation construction technical scheme, and slurry should not leak from the seam of the template; 3) the waterproof concrete adopts premixed commercial concrete, and the slump in the pump is controlled to be 160 mm; continuously pouring concrete, and preferably leaving few construction joints;
s6, dismantling the steel support;
1) the steel support is dismantled, the stress of the steel support is released, the loose end is loosened, and the steel support is dismantled one by one;
2) dismantling steel supports and cast-in-place piles of the steel sheet piles: after the concrete of the bottom plate and the side wall reaches 100% of the design strength, the second steel support can be disassembled, and after the concrete strength of the main structure of the tunnel reaches 100% of the design strength, the first steel support can be disassembled; after the steel support is dismantled, the steel sheet pile is pulled out, and before the steel sheet pile is pulled out, the surrounding environment is carefully observed, and corresponding measures are taken to reduce the damage to the surrounding environment; the pile pulling sequence is opposite to the pile driving sequence; after the pile body is pulled out, the pile hole is timely backfilled with graded sandstone; the steel sheet pile is pulled out by a vibration hammer and a crane together;
2 hydraulic jacks of 30 tons are placed into the loose end to release stress of the steel support, the jacking force of the jacks is consistent, the two jacks are fixed into a whole by adopting special brackets, a pump can be started to apply prestress after an oil pipe is connected, the steel wedge block in the loose end is taken out in time after the prestress is applied in place, and the steel wedge block is slowly put down after the connection is removed;
step S7, construction joint processing
The horizontal construction joints of the wall are left on the wall which is not less than 300mm higher than the surface of the bottom plate; before the horizontal construction joint is used for casting concrete, removing floating slurry and sundries on the surface of the horizontal construction joint, then laying clean slurry or coating a concrete interface treating agent or coating a cement-based permeable crystallization type waterproof coating, then laying 1:1 cement mortar with the thickness of 30-50mm, and casting the concrete in time;
step S8, construction of side wall and top plate structure
Performing waterproof construction on the side wall and the top plate; the concrete method of waterproof construction comprises the following steps: the waterproof concrete for the side wall and the top plate is prepared by adjusting the mixing proportion or adding an additive and an admixture, and the anti-permeability grade of the waterproof concrete is not less than P6; the structural waterproofing adopts a mode of combining concrete structural self waterproofing with a waterproof coiled material; the deformation joints of the top plate and the wall plate adopt a middle-buried steel-edged rubber water stop, 30mm thick polyethylene low-foaming joint filling and 30-by-30 two-component polysulfide sealant caulking;
step S9, lateral and roof earthwork backfilling
Backfilling and tamping the backfill soil layer by layer according to the design requirement; in the filling and tamping process, the filler is filled and tamped layer by layer, and the number of times of tamping is 3-4 times per layer, so that the construction is completed.
2. The urban rail transit cable line tunnel construction method according to claim 1, wherein the steel sheet pile visual inspection in step S2 comprises: the steel sheet pile with the end socket being not in accordance with the shape requirement is corrected by the surface defects, the length, the width, the height, the thickness, the end socket rectangular ratio, the flatness and the locking notch shape, so that the piling difficulty and the pile position deviation are reduced; the steel sheet pile correction comprises surface defect repair, end plane correction, pile body deflection and distortion correction, pile body local deformation correction and locking notch deformation correction.
3. The urban rail transit cable line tunnel construction method according to claim 1, wherein the hole cleaning manner in step S2 is to use a flat bottom double door type hole cleaning drill for hole cleaning.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811044177.6A CN108842819B (en) | 2018-09-07 | 2018-09-07 | Urban rail transit cable line tunnel construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811044177.6A CN108842819B (en) | 2018-09-07 | 2018-09-07 | Urban rail transit cable line tunnel construction method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108842819A CN108842819A (en) | 2018-11-20 |
| CN108842819B true CN108842819B (en) | 2020-06-16 |
Family
ID=64189087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811044177.6A Active CN108842819B (en) | 2018-09-07 | 2018-09-07 | Urban rail transit cable line tunnel construction method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108842819B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110080243A (en) * | 2019-04-28 | 2019-08-02 | 中国一冶集团有限公司 | A kind of Larsen steel sheet pile closed in the case of structures beats, draw out method |
| CN110242320B (en) * | 2019-05-27 | 2020-11-10 | 中建交通建设集团有限公司四川分公司 | A method of excavating a steel pipe column in the middle of a subway station |
| CN111926822A (en) * | 2020-07-29 | 2020-11-13 | 武汉光谷电力科技有限公司 | Traffic cable line tunnel construction method and fender post mounting structure |
| CN111946396B (en) * | 2020-08-03 | 2022-04-29 | 中交第三航务工程局有限公司 | Innovative tunnel dismantling process |
| CN112962617A (en) * | 2021-02-06 | 2021-06-15 | 中冶成都勘察研究总院有限公司 | Comprehensive pipe gallery foundation pit supporting method for weathered rock stratum area |
| CN113250169B (en) * | 2021-04-07 | 2022-08-30 | 苏现锋 | Method for monitoring foundation pit of constructional engineering |
| CN114319421B (en) * | 2021-11-05 | 2025-01-21 | 北京市政建设集团有限责任公司 | A U-shaped tunnel and integrated pipe gallery shared structure and deformation control method thereof |
| CN114837223B (en) * | 2022-06-07 | 2024-07-02 | 浙江交工地下工程有限公司 | Construction method of cast-in-situ pipe gallery and box type tunnel sharing enclosure system |
| CN117345944A (en) * | 2023-08-30 | 2024-01-05 | 中国化学工程第十四建设有限公司 | Buried installation process of large-caliber PCCP pipeline on complex foundation |
| CN116933609B (en) * | 2023-09-15 | 2023-12-12 | 中铁电气化局集团有限公司 | In-phase traction power supply cable power supply loop guide connection construction simulation method and system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004052398A (en) * | 2002-07-22 | 2004-02-19 | Kajima Corp | Construction method for underground structures |
| CN102363961A (en) * | 2011-11-11 | 2012-02-29 | 中交四航局第一工程有限公司 | A deep-water single-wall steel sheet pile cofferdam structure with small depth of penetration and its construction method |
| CN106049531A (en) * | 2016-06-08 | 2016-10-26 | 杭州江润科技有限公司 | Construction method for high-water-content ultra-soft soil box type multi-chamber cast-in-place frame tunnel |
| CN107023043A (en) * | 2017-05-26 | 2017-08-08 | 中国十七冶集团有限公司 | A kind of deep foundation pit supporting construction monitoring and pre-alarming method |
| CN107724401A (en) * | 2017-09-15 | 2018-02-23 | 浙江申诚环境工程有限公司 | The construction method of bridge pier foundation ditch |
| CN108343071A (en) * | 2018-03-19 | 2018-07-31 | 南京市测绘勘察研究院股份有限公司 | A kind of foundation pit supporting construction and construction method of steel sheet pile combined deposited pile |
-
2018
- 2018-09-07 CN CN201811044177.6A patent/CN108842819B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004052398A (en) * | 2002-07-22 | 2004-02-19 | Kajima Corp | Construction method for underground structures |
| CN102363961A (en) * | 2011-11-11 | 2012-02-29 | 中交四航局第一工程有限公司 | A deep-water single-wall steel sheet pile cofferdam structure with small depth of penetration and its construction method |
| CN106049531A (en) * | 2016-06-08 | 2016-10-26 | 杭州江润科技有限公司 | Construction method for high-water-content ultra-soft soil box type multi-chamber cast-in-place frame tunnel |
| CN107023043A (en) * | 2017-05-26 | 2017-08-08 | 中国十七冶集团有限公司 | A kind of deep foundation pit supporting construction monitoring and pre-alarming method |
| CN107724401A (en) * | 2017-09-15 | 2018-02-23 | 浙江申诚环境工程有限公司 | The construction method of bridge pier foundation ditch |
| CN108343071A (en) * | 2018-03-19 | 2018-07-31 | 南京市测绘勘察研究院股份有限公司 | A kind of foundation pit supporting construction and construction method of steel sheet pile combined deposited pile |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108842819A (en) | 2018-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108842819B (en) | Urban rail transit cable line tunnel construction method | |
| CN106958256A (en) | A kind of placement layer by layer, the open caisson construction technique repeatedly sunk | |
| CN112593559A (en) | Construction method for deep foundation pit supporting of micro-pile prestressed anchor cable composite soil nailing wall | |
| CN109914161B (en) | Construction method of high-speed railway filling roadbed in soft soil area | |
| CN111503368B (en) | Pipe jacking construction method under sandy gravel geological condition | |
| US11959243B2 (en) | Method for constructing large-span station with two-wing open type half-cover excavation and half-reverse construction | |
| CN114411761B (en) | Advanced pre-supporting system and method for subway tunnel to be built in new building construction | |
| CN103015429A (en) | Long auger rotary-jet mixing steel reinforced cement-soil pile foundation pit water-resisting and supporting method | |
| CN111560958A (en) | Construction method of water-rich deep foundation pit in silty clay stratum | |
| CN110306989B (en) | Non-open-cut assembled pipe trench excavation supporting and reinforcing method | |
| CN112609690A (en) | Construction method of rotary drilling cast-in-place pile in sea-filling geological complex area | |
| CN112144559A (en) | Construction method of piezo-transformer tube well in high water-rich loess sandy pebble formation | |
| CN206736963U (en) | Ditch millet section high water level district lid tunnel stagnant water structure | |
| CN109577322A (en) | A kind of constructing device for inside soil body existing pile foundation pile extension | |
| CN111379273A (en) | Construction method of corrugated steel comprehensive pipe gallery | |
| CN110924401A (en) | Construction foundation pit supporting mode for combined arching and bearing of mixing piles and cast-in-place piles | |
| CN117345944A (en) | Buried installation process of large-caliber PCCP pipeline on complex foundation | |
| CN113529830B (en) | Shallow Buried Tunnel Adjacent Building Isolation-Underpinning Combination Reinforcement Structure and Its Construction Technology | |
| CN114319432B (en) | Construction process of semi-underground subway station and semi-underground subway station | |
| CN110512594A (en) | The simple and easy method of churning driven opportunity cavity pore-forming | |
| CN113685190B (en) | Reinforcing system for shield to penetrate shallow soft clay and construction method | |
| CN115404885A (en) | Gradual retaining construction method suitable for multi-step high and steep slopes | |
| CN114991165A (en) | Construction method for subway deep foundation pit adjacent to railway business line | |
| CN113550764A (en) | Method for starting shield concrete sleeve to enter hole and building structure | |
| CN113266019A (en) | Construction method of foundation pit steel pipe support system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 230000 no.218, Xiangzhang Avenue, hi tech Development Zone, Hefei City, Anhui Province Patentee after: China Energy Construction Group Co.,Ltd. Address before: No. 218, Xiangzhang Avenue, high tech Zone, Hefei City, Anhui Province, 230088 Patentee before: China Energy Engineering Group Anhui No.1 Electric Power Construction Co.,Ltd. |