A kind of full casing follow-up step construction method of bridge pile foundationTechnical field
The invention discloses one kind to be used for the full casing follow-up step construction method of bridge pile foundation, and in particular to a kind of Earthquake FaultingWith complicated geological layer, soil layer weak broken, rich in the full casing follow-up step construction method in the stratum such as underground water, easy collapse hole.
Background technology
Disorderly on fracture belt stratum at bridge pile foundation, rock mass weak broken, pile foundation passes through dust tomography more, and pore-forming is strandedDifficulty, easy collapse hole in pore forming process, easy undergauge, so that pile foundation construction quality is difficult to control, it is ensured that the bad ground pile foundation construction matterAmount turns into problem.
The content of the invention
The purpose of the present invention is difficult above to solve, and designs a kind of full casing follow-up step construction method of bridge pile foundation, realBorder application display, this full casing follow-up pile base construction method is simple and efficient, and cost is low, high safety, and quality is guaranteed.
The technical scheme is that：A kind of full casing follow-up step construction method of bridge pile foundation, including：(1) casing designsWith making：Using multiple casings, can mutually be dismantled between each casing；(2) first section casing installation：Head section casings are bored with rigHead is connected, and when drill bit of drilling machine direction of rotation is consistent with drill bit drilling direction, casing fastens with drill bit, when opposite direction rotatesCan unlock drill bit of drilling machine and casing state, facilitate and drill bit is carried in borer drilling procedure go out boring mud.Examine after mounting firstConcentricity, the perpendicularity of casing and drill bit of drilling machine are saved, ensures perpendicularity of the casing in follow-up drilling process；Head section casing lengthDetermined according to surficial geology and drill bit of drilling machine single drilling depth, to ensure drilling progress, head section casings are typically no less than 2m；(3) casing Follow-up type bored pile：According to the stake position after setting-out, by drill bit of drilling machine center align piles position, vertical drilling, with stake positionFace on the basis of ground, when the upper surface of casing is higher by reference plane H, next casing is connect, until reaching projected depth；(4) stakeBase concrete is irrigated and casing is extracted：Crept into after stake holes to projected depth, lay pile foundation steel bar cage, concrete perfusion, mixedCoagulate in native filling process, casing Transducers Embedded in Concrete length is calculated according to concrete perfusion quantity and casing diameter, treats that casing buriesEnter concrete length to meet when requiring, extract casing.
It is of the invention effective to overcome in the easy collapse hole of fracture belt weak broken stratum construction bridges pile foundation boring, easy undergaugeDifficulty, pore-forming hole wall by the synchronous casing that follows up timely protection, no longer occur in drilling process because tomography geology is broken andCaused hole wall collapse, sediment the problems such as so as to efficiently solve the collapse hole occurred in drilling process, bit freezing and after pore-forming borehole cleaningThere is the problems such as excessive velocities；Bad ground pile foundation construction quality is effectively ensured, it is ensured that the security of pile foundation construction, improveEfficiency of construction, reduces cost.
Such scheme uses multiple casings, from the surface, using the casing of multiple segmentations than using a long shieldCylinder is more time-consuming, in fact, the casing of multiple segmentations, can reduce the time that drilling is extracted with casing.And long casing is compared,Shorter casing, beneficial to the positioning between drill bit of drilling machine and stake position, positioning is simpler, more accurately.
Formed preferably, casing is rolled using 30mm steel plates, be 2-3m per segmental height, the technical characteristic is that synthesis is examinedConsider the factors such as pile foundation drilling diameter, casing intensity, pile foundation Bedrock Geology condition and churning driven service behaviour index and determine.2-3 meters of height as a casing, while a drilling stroke of rig is also served as, be advantageous to the drilling progress of rig, be beneficial toPositioning between drill bit and stake position.
Preferably, the top of the casing is provided with first connecting portion, all shields in addition to the casing of head sectionsThe bottom of cylinder is provided with second connecting portion, passes through the second of the first connecting portion of previous casing and latter casing between adjacent casingConnecting portion is connected.
It can between each other connect, can also be not connected between casing, by the way of connection, be advantageous in step (4)The extraction of casing, save the engineering time.
Preferably, the internal diameter of the first connecting portion is less than the internal diameter of the second connecting portion, and first connectionThe first screwed hole is provided with portion, the second screwed hole is provided with second connecting portion, between first connecting portion and second connecting portionIt is bolted.It is simple to operate.
Preferably, being provided with hanging hole in the first connecting portion, hook, institute are hinged with the outside of the second connecting portionState and be attached between first connecting portion and second connecting portion by linking up with hanging hole.It is simple to operate.
Preferably, the casing includes the two panels casing piece being hinged, casing piece is away from pin joint described in two panelsOne end is connected by buckling piece.In the vertical direction is detachably connected between casing, can also be beaten in the transverse direction of casing in itselfOpen, by the technical scheme, during drilling, after the drill bit of rig often bores the depth of a casing height, covered again without taking out drill bitIf next casing, and directly casing can be put, greatly save drilling time.
Preferably, after the completion of pile-casting making, before use, carry out casing preassembling：The casing machined is being appliedWork scene carries out preassembling, examines casing to connect horizontal, vertical limiter positional accuracy and reliability, ensures that casing can be by anticipationRequirement embedment and extract.
Preferably, whole casing is numbered after the completion of preassembling, when pressing preassembling during subsequent constructionNumbering carries out casing spreading and dismounting.
Preferably, also including the maintenance to casing and casing quantity configuration, to ensure that rig can work continuously, machine is improvedTool utilization rate of equipment and installations, casing is covered according to rig rate of penetration and pile foundation filling concrete, pipe-pulling speed reasonable disposition 1.5-2, withMeet that rig can start the drilling of next pile base pile hole in a pile base in perfusion.
Preferably, the extraction of casing, is ejected casing merogenesis with hydraulic push bench, single push pipe length is single-unit casingLength.
Preferably, vertical fin or spiral ridge are provided with the outer surface of the casing.The setting of fin, it is existingHelp drilling construction, accelerate the progress of drilling, and can enough reduces resistance when casing is extracted.
By implementing above-mentioned technical proposal, the present invention is effectively overcome in the construction bridges stake of fracture belt weak broken stratumBase drills easy collapse hole, the difficulty of easy undergauge, pore-forming hole wall by the synchronous casing that follows up timely protection, in drilling process no longerThere is the hole wall collapse caused by tomography geology is broken, so as to efficiently solve the collapse hole occurred in drilling process, bit freezing etc.There is the problems such as excessive velocities in sediment after problem and pore-forming borehole cleaning；Bad ground pile foundation construction quality has been effectively ensured, it is ensured thatThe security of pile foundation construction, has saved the engineering time, improves efficiency of construction, reduces cost.
Brief description of the drawings
Accompanying drawing 1 is the schematic diagram of casing in one embodiment of the invention；
Accompanying drawing 2 is the connection diagram of casing shown in accompanying drawing 1；
Accompanying drawing 3 is casing schematic diagram in another embodiment of the present invention；
Accompanying drawing 4 is the top view of casing in another embodiment of the present invention.
In figure, 1- casings；11- first connecting portions；12- second connecting portions；The screwed holes of 111- first；112- hanging holes；121-Second screwed hole；122- is linked up with；The vertical fins of 13-.
Embodiment
Below in conjunction with the accompanying drawings and specific embodiment, the present invention is described in further detail.
Embodiment 1：
A kind of casing external member for Bridge Pile Foundation Construction, including multiple casings 1, shown in the Structure Figure 1 of casing 1, casing 1Top is provided with first connecting portion 11, and the bottom of all casings 1 in addition to the casing 1 of head sections is provided with second connecting portion12, the internal diameter of first connecting portion 11 is less than the internal diameter of the second connecting portion 12, and the is provided with the first connecting portion 11One screwed hole 111, the second screwed hole 121 is provided with second connecting portion 12, is bolted between adjacent casing 1, it is such as attachedShown in Fig. 2.
A kind of full casing follow-up step construction method of bridge pile foundation, it is soft to be mainly used in Earthquake Fault Zone complicated geological layer, soil layerIt is weak to crush, include rich in the stratum such as underground water, easy collapse hole, its specific method：(1) casing design and fabrication：Consider pile foundationThe factors such as drilling diameter, casing intensity, pile foundation Bedrock Geology condition and churning driven service behaviour index, calculated according to foregoing experienceFormula, casing material use 30mm roll of steel plate, are 2m per segmental length；(2) first section casing installation：To examine qualified casing withDrilling bit of rotary-digging drilling rig is connected, and when bit direction is consistent with drill bit drilling direction, casing fastens with drill bit, works as opposite directionCan unlock drill bit and casing during rotation state, facilitate and drill bit is carried in borer drilling procedure go out boring mud.Examine after mountingConcentricity, the perpendicularity of head section casings and drilling bit of rotary-digging drilling rig, ensure perpendicularity of the casing in follow-up drilling process；(3) protectCylinder Follow-up type bored pile：According to the stake position after setting-out, by bit central align piles position, vertical drilling, using stake position ground as baseQuasi- face, when the upper surface of casing is higher by reference plane H, next casing is connect, until reaching projected depth；Pore-forming hole wall byThe timely protection of synchronous follow-up casing, no longer there is the hole wall collapse caused by tomography geology is broken in drilling process, so as toThere is the problems such as excessive velocities in sediment after the problems such as efficiently solving the collapse hole occurred in drilling process, bit freezing and pore-forming borehole cleaning；(5) pile foundation filling concrete and casing are extracted：Crept into after stake holes to projected depth, by technical requirements, carry out borehole cleaning, lay stakeBase steel reinforcement cage, concrete perfusion.During filling concrete, shield is calculated according to concrete perfusion quantity and steel pile casting diameterCylinder Transducers Embedded in Concrete length, with hydraulic push bench by Follow-up type casing merogenesis top when casing Transducers Embedded in Concrete length meets to requireGo out, be advisable in principle by single-unit casing length of single push pipe length.
Embodiment 2：
A kind of casing external member for Bridge Pile Foundation Construction, including multiple casings 1, the top of casing 1 are provided with first connecting portion11, the bottom of all casings 1 in addition to the casing 1 of head sections is provided with second connecting portion 12, first connecting portion 11 it is interiorFootpath is less than the internal diameter of the second connecting portion 12, and hanging hole 112 is provided with the first connecting portion 11, second connecting portion 12Outside is hinged with hook 122, as shown in Figure 3, is attached between adjacent casing 1 by hook 122 with hanging hole 112.Casing 1Outer surface on be provided with vertical vertical fin 13, as shown in Figure 4.
A kind of full casing follow-up step construction method in bridge pile foundation difficulty pore-forming stratum, including：(1) casing design and fabrication：It is comprehensiveClose and consider the factors such as pile foundation drilling diameter, casing intensity, pile foundation Bedrock Geology condition and churning driven service behaviour index, according to precedingEmpirical formula is stated, casing is rolled using 30mm steel plates and formed, and is 3m per segmental length；(2) casing examination is assembled：To processingInto casing carry out preassembling at the construction field (site), examine casing to connect horizontal, vertical limiter positional accuracy and reliability, ensureCasing can be embedded to and extracted by the requirement of anticipation.Whole casing is numbered after the completion of preassembling, during subsequent constructionCasing spreading and dismounting are carried out by numbering during preassembling；(3) first section casing installation：Preassembling is examined into qualified casing and rotationDig drill bit of drilling machine to be connected, when bit direction is consistent with drill bit drilling direction, casing fastens with drill bit, when opposite direction is revolvedCan unlock drill bit and casing when turning state, facilitate and drill bit is carried in borer drilling procedure go out boring mud.Examine after mounting firstConcentricity, the perpendicularity of casing and drilling bit of rotary-digging drilling rig are saved, ensures perpendicularity of the casing in follow-up drilling process；(4) casingFollow-up type bored pile：According to the stake position after setting-out, by bit central align piles position, vertical drilling, on the basis of the ground of stake positionFace, when the upper surface of casing is higher by reference plane H, connect next casing, pore-forming hole wall by synchronous the timely of casing of following upProtect, no longer occur the hole wall collapse caused by tomography geology is broken in drilling process, so as to efficiently solve drilling processThere is the problems such as excessive velocities in sediment after the problems such as collapse hole of middle appearance, bit freezing and pore-forming borehole cleaning；(5) pile foundation filling concrete andSteel pile casting is extracted.Crept into after stake holes to projected depth, by technical requirements, carry out borehole cleaning, lay pile foundation steel bar cage, irrigate coagulationSoil.During filling concrete, casing Transducers Embedded in Concrete length is calculated according to concrete perfusion quantity and steel pile casting diameter,Follow-up type casing merogenesis is ejected with hydraulic push bench when casing Transducers Embedded in Concrete length meets to require, in principle with single topLength of tube is that single-unit casing length is advisable；(6) casing maintenance and casing quantity configuration.To ensure that rotary drilling rig can work continuously,Plant equipment utilization rate is improved, according to rotary drilling rig rate of penetration and pile foundation filling concrete, pipe-pulling speed reasonable disposition 1.5 ~ 2Follow-up type casing is covered, to meet that rotary drilling rig can start the drilling of next pile base pile hole in a pile base in perfusion.
It is of the invention effective to overcome in the easy collapse hole of fracture belt weak broken stratum construction bridges pile foundation boring, easy undergaugeDifficulty, bad ground pile foundation construction quality is effectively ensured, it is ensured that the security of pile foundation construction, improve efficiency of construction, dropLow cost.
Embodiment 3：
A kind of casing external member for Bridge Pile Foundation Construction, including multiple casings 1, the top of casing 1 are provided with first connecting portion11, the bottom of all casings 1 in addition to the casing 1 of head sections is provided with second connecting portion 12, first connecting portion 11 it is interiorFootpath is less than the internal diameter of the second connecting portion 12, and hanging hole 112 is provided with the first connecting portion 11, second connecting portion 12Outside is hinged with hook 122, is attached between adjacent casing 1 by hook 122 with hanging hole 112.Set on the outer surface of casing 1It is equipped with spiral ridge.
A kind of full casing follow-up step construction method in bridge pile foundation difficulty pore-forming stratum, including：(1) casing design and fabrication：It is comprehensiveClose and consider the factors such as pile foundation drilling diameter, casing intensity, pile foundation Bedrock Geology condition and churning driven service behaviour index, according to precedingEmpirical formula is stated, casing is rolled using 30mm steel plates and formed, and is 2.5m per segmental length；(2) casing examination is assembled：To processingThe casing of completion carries out preassembling at the construction field (site), examines casing to connect horizontal, vertical limiter positional accuracy and reliability, protectsCasing is demonstrate,proved to be embedded to and extracted by the requirement of anticipation.Whole casing is numbered after the completion of preassembling, in subsequent construction processIn numbering when pressing preassembling carry out casing spreading and dismounting；(3) first section casing installation：By preassembling examine qualified casing withDrilling bit of rotary-digging drilling rig is connected, and when bit direction is consistent with drill bit drilling direction, casing fastens with drill bit, works as opposite directionCan unlock drill bit and casing during rotation state, facilitate and drill bit is carried in borer drilling procedure go out boring mud.Examine after mountingConcentricity, the perpendicularity of head section casings and drilling bit of rotary-digging drilling rig, ensure perpendicularity of the casing in follow-up drilling process；(4) protectCylinder Follow-up type bored pile：According to the stake position after setting-out, by bit central align piles position, vertical drilling, using stake position ground as baseQuasi- face, when the upper surface of casing is higher by reference plane H, connect next casing, pore-forming hole wall by the synchronous casing that follows up andWhen protect, no longer occur the hole wall collapse caused by tomography geology is broken in drilling process, crept into so as to efficiently solveThere is the problems such as excessive velocities in sediment after the problems such as collapse hole that occurs in journey, bit freezing and pore-forming borehole cleaning；(5) pile foundation filling concreteAnd steel pile casting is extracted.Crept into after stake holes to projected depth, by technical requirements, carry out borehole cleaning, lay pile foundation steel bar cage, perfusion is mixedSolidifying soil.During filling concrete, casing Transducers Embedded in Concrete length is calculated according to concrete perfusion quantity and steel pile casting diameterDegree, Follow-up type casing merogenesis is ejected with hydraulic push bench when casing Transducers Embedded in Concrete length meets to require, in principle with listSecondary push pipe length is that single-unit casing length is advisable；(6) casing maintenance and casing quantity configuration.To ensure that rotary drilling rig can continuously be madeIndustry, plant equipment utilization rate is improved, according to rotary drilling rig rate of penetration and pile foundation filling concrete, pipe-pulling speed reasonable disposition1.5 ~ 2 sets of Follow-up type casings, to meet that rotary drilling rig can start the brill of next pile base pile hole in a pile base in perfusionEnter；(7) construction that (3)-(6) continue to complete remaining bridge pile foundation is repeated.