CN110512594A - The simple and easy method of churning driven opportunity cavity pore-forming - Google Patents

Abstract

A kind of simple and easy method of churning driven opportunity cavity pore-forming, comprising steps of 1, determine stake position；2, it respectively constructs one outside the both ends in the cavity of construction area and protects stake, the both ends in cavity are blocked；3, the stake holes with the protection stake every a pile position is excavated, the good soil dug out is directly inserted in the protection stake holes of end, earth filling tamping；4, using the method constructed every hole, the stake holes of every pile in construction area is using first digging to cavity, inserting the stake holes with the good soil of adjacent stake holes and tamping, until until ramming completely；5, the intermediate stake holes dug of jumping is dug again, bankets, tamp, until whole pile hole constructions is completed；6, since the centre of construction area, the bore forming in all construction areas is completed using common process.The invention has the advantages that under conditions of not increasing the duration, completing whole pile driving constructions at cavity hardly increasing cost.Economic benefit, environmental benefit and social benefit are significant.

Description

The simple and easy method of churning driven opportunity cavity pore-forming

Technical field

The present invention relates to a kind of simple and easy method of churning driven opportunity cavity pile, belong in building foundation construction at Stake, can be used for the construction of slope protection pile, compressive pile, resistance to plucking anti-floating pile etc..

Background technique

Soil cave or solution cavity etc. are encountered in rotary drilling rig drilling process both at home and abroad at present, the method expected first is filling, to Throwing slabstone in hole backfills lean concrete, and there are also auxiliary with slip casing by pressure, and there are also the construction technologies using steel pile casting follow-up.

Backfilled using slabstone, when drilling solution cavity spillage, put into loess and slabstone repeatedly, using drill bit impact by loess and Slabstone is squeezed into solution cavity and Karst Fissures, and cement, caustic soda and sawdust can be also mixed, to increase the self-stable ability of hole wall.

Lean concrete backfill, generallys use C20 lean concrete, to improve early strength, saves the time, adds in concrete Enter early strength agent.It is higher than Upper Plate of Karst Cave 50cm for backfilling top surface at solution cavity.For inclined rock base, to correct hole location, backfill poor mixed Solidifying soil should be with inclined rock base either flush.Concrete strength, which reaches 70% side, after backfill 48h to spud in again.

Grouting method processing cavern is highly effective measure, and injected hole arrangement first finds out maximum according to design data Solution cavity, if solution cavity be connection solution cavity, it is only necessary to maximum solution cavity carry out grouting and reinforcing.

Steel pile casting follow-up technique has a kind of entitled Bei Nuote (Benote) engineering method in foreign countries, is a full set of using full circle swinging Prefabricated steel sleeve is pressed into stratum to certain depth by 360 ° of revolutions by pipe drilling machine, and being grabbed bucket by punching will be in steel sleeve The soil body takes out, then is gradually pressed into casing pipe hole forming, finally hangs steel reinforcement cage, concrete perfusion, acts the construction method for pulling out steel sleeve.This It is presently a kind of more expensive method that kind method, which needs special equipment,.Some small engineerings are especially tackled, are just seemed Some " kill chicken knife of slaughtering an ox ".

The method that " flying pipe " is thrown away in also oriented hole, this method need to convert drilling diameter, or use large diameter borehole in advance, Encounter under cavity after complete winged pipe, change diameter drilling, or under after complete " flying pipe ", change smaller level-one diameter drilling.This method is aobvious and easy See and a kind of more troublesome method, is also required to process the steel pipe of heavy wall in advance certainly, becomes diameter if design disagrees Small, that first reforms into unique selection using big level-one diameter aperture.It is completely successful nevertheless, cannot guarantee that, Ke Nengfei Pipe lower end also has a cavity, then winged pipe lower end closed it is bad, can also spillage.What is more, and drill bit will fly in drilling process Pipe, which touches pine or touches to break, touches folding.

We also once designed fixes thin steel pile casting or iron sheet casing in reinforcing steel bar cage, with steel reinforcement cage together tripping in In hole, concrete perfusion pile, but it is unsuccessfully that thin steel pile casting or iron sheet casing can be burst by concrete that this method is possible, Or thin steel pile casting or iron sheet casing flows out after filling from upper end, into cavity, wastes concrete, or even fill discontented.Certainly Also it needs to process thin steel pile casting or iron sheet casing in advance.

Also once design is used by empty side brick masonry in artificial tripping in hole, but this operation is danger close, once it collapses It collapses, people will be buried, it is clear that everybody, which disagrees, emits this danger.

No matter the above various methods economically or on the duration will all pay comparable cost.It should can invent The more economical method more to save time out.

Summary of the invention

Speed is robbed in order to strive the time, using the condition at scene, gathers materials on the spot, is solved the above problems using existing equipment, this Invention provides a kind of simple and easy method of churning driven opportunity cavity pore-forming.

The technical scheme is that a kind of simple and easy method of churning driven opportunity cavity pore-forming, it is characterised in that: packet Include following steps:

(1), the cavity trend and tip position for needing construction area are found out, place is flattened, determines stake position；

(2), it respectively constructs one outside the both ends in the cavity of construction area and protects stake, the both ends in construction area cavity are blocked；

(3), the stake holes with the protection stake every a pile position is excavated, by the protection stake (hole) of the good soil dug out directly filling end In, every a pipeful of good soil of filling, by rotary bucket when hammer ram is used, with strength by earth filling tamping, upper surface of banketing pushes up upper 0.5 to cavity~ 1.0m, banketing can arbitrarily spread to empty periphery, but until the soil in cavity is all tamped；

(4), using the method constructed every hole, for the stake holes of every pile in construction area using first digging to absolutely empty hole bottom, use is adjacent The good soil of stake holes insert and the stake holes and tamp, until the upper surface location that bankets is identical as step (3) until ramming and expiring；

(5), the intermediate stake holes dug of jumping is dug again, bankets, tamp, until whole pile hole constructions is completed；

(6), since the centre of construction area, the bore forming in all construction areas is completed using common process.

In the step (2), the construction method of the protection stake: excavates one and banket hole to empty bottom, and banket to cavity Interior compacting.

Pile in the step (3) will construct every hole, avoid perforating, and stake holes can stop when digging to empty bottom end Come, carries out back-filling in layers, compacting using the good soil that this stake holes and adjacent stake holes are dug out；It can be provided when excavating stake holes for formal pile One stable basic condition not collapsed.

In the step (6), the stake holes for intending construction pile excavates pore-forming from centre, then successively verifies, hangs in reinforcing bar Cage, concrete perfusion pile；Construction is played using jumping, it is ensured that the minimal disturbances of hole wall when pore-forming, when also guaranteeing concrete perfusion Whole constructions of central pile are completed in minimal impact to hole wall.

The invention has the advantages that under conditions of not increasing the duration, completing the whole at cavity hardly increasing cost Pile driving construction.Economic benefit, environmental benefit and social benefit are significant.

Detailed description of the invention

Fig. 1 is construction flow chart of the invention；

Fig. 2 is that the present invention bankets that (cross-sectional view along cavity and stake holes merely illustrates in figure in the first round construction process schematic Structure after banketing in pile stake holes).

Description of symbols: 1, empty, 2, protection stake holes, 3, the pile stake holes skipped of first round construction (apply by the i.e. second wheel The pile stake holes of work), 4, the pile stake holes of first round construction, 5, (banketing to be formed in protection stake holes) protection stake, 6, pile stake Banketing in hole, 7, banketing and (merely illustrating at one) in the pile stake holes of the second wheel construction, 8, ground.

Specific embodiment

Referring to Fig. 1 and Fig. 2, the typical process flow of the simple and easy method of a kind of churning driven opportunity of the invention cavity pore-forming Include:

1, the simple and easy method of churning driven opportunity cavity pore-forming, gathers materials on the spot, and solves the problem using existing equipment.Specific step Suddenly it is:

(1), 1 trend of cavity and tip position are found out, it is first determined the position in cavity 1 and trend determine the cavity 1 with quasi- construction The relationship (how many quasi- construction stake is fallen into the range of cavity 1) of stake (hole), flattens place, releases stake position, fastened stake position.

(2), intend respectively increasing a guarantor at the cavity 1 outside the both ends of the stake holes 3,4 of construction stake (falling into empty range) The construction method of fender pile 5, protection stake 5 is: a protection stake holes 1 is respectively dug out outside both ends to cavity 1, first from the protection stake of one end Hole 1 starts, and the mound dug out is put side, is communicated until digging in this pile hole to cavity 1.It is dug out with hole of every hole and originally banketing Good soil filling (to banketing in hole) and tamp, form the protection stake 5 at empty 1 both ends, realize the closure to empty 1 both ends, really It will not outflow to both ends when protecting two ends pile driving construction.

(3), pile stake holes 4(, that is, first round construction pile stake holes is excavated every a pile hole 3), the good soil dug out is directly filled out Enter in the protection stake holes 1 of end, a pipeful of good soil of every filling, by rotary bucket when hammer ram is used, with strength by earth filling tamping, soil can be to sky Hole periphery is arbitrarily spread, but up to all compactings of the soil in cavity, formation protection stake 5.Banketing in protection stake holes 1 (is protected 5) upper surface is higher than hole top 0.5-1m for stake.

(4), same method is by the protection stake 5 of another end, in this way earth filling tamping.

(5), it constructs every hole, often skips a pile stake holes 3 and construct intermediate pile stake holes 4 to cavity 1, with the good soil every hole Insert and tamp, until ram it is full until, form pile stake holes and banket 6.

(6), all pile stake holes 3 for skipping of centre are dug, banketed, tamped, formation pile stake holes bankets 7.So far will Banketing for whole stake holes is disposed.Then the construction for carrying out concrete pile is (following to be applied using conventional bore forming technique Work forms concrete pile).

(7), since centre, normal borehole is verified after pore-forming, tripping in steel reinforcement cage, concrete perfusion pile.

(8), it excavates every hole, normal borehole, verifies after same pore-forming, tripping in steel reinforcement cage, concrete perfusion pile.

(9), the pile of empty 1 end (i.e. stake holes 3) of finally construction.Thus hardly increase cost, does not increase work Under conditions of phase, whole pile driving constructions at cavity are completed.

The pile stake holes 4 of pile stake holes 3, first round construction that the first round construction is skipped is initially used for cavity 1 It inside bankets, after the completion of banketing, is used further to the construction (above-mentioned step 7-9) of concrete pile.

In the step (5) and (6), quasi- construction stake 3 will construct every hole, avoid perforating, and dig to cavity 1 and communicate, benefit The sum dug out with this hole carries out back-filling in layers, compacting every the good soil that hole is dug out.Next formal pile can form one surely when excavating The fixed stake holes that do not collapse.Pore-forming to cavity 1, backfill, compacting is returned then every hole pore-forming to cavity 1 since stake is protected in end It fills out, tamps, successively handle, all processing in place, is formally constructed wound for lower step stake by the stake position on all cavities to be treated Make condition.

In the step (7) and (8), intend construction stake 3 and excavate since centre, pore-forming is verified, and steel reinforcement cage is hung in, and is filled Infuse concrete pile.Construction is played in jump, it is ensured that the minimal disturbances of hole wall when pore-forming, also when guarantee concrete perfusion to hole wall most Whole constructions of central pile are completed in small impact.The stake at empty (antiaircraft tunnel) both ends of finally construction.

The present invention is described in detail combined with specific embodiments below:

1, surveying setting-out fixed pile: cavity trend and tip position, the surveying setting-out fixed pile on smooth location, In are found out first Stake position both ends increase " protection stake ", and guide pile is carried out with measuring instrument in both ends, prevents stake position from checking at any time when there is deviation；Determine stake Position is usually to make a call to a deep hole on the ground with drill rod or punch, pours into albarium powder, and reinforcing rod etc. is plugged at stake position and is obviously marked Will.When necessary, which is projected on the wall of distant place, review is used at any time.

, confirmation cavity trend and its end, manually examine on the spot using existing underground utilities drawing or in addition, when necessary It is reconnoitred in into cavity, such as old or discarded antiaircraft tunnel, determines its trend and end, get the mutual pass with stake position clear System.Increase " protection stake " outside end, both ends in place, can thus be blocked first, be avoided by " protection stake " processing first It is lost to outside both ends.

, end protection stake excavation earth filling tamping, trend and its both ends of empty (antiaircraft tunnel) are found out, first from one end Protection stake starts, and the mound dug out is put side, until digging this pile to the upper end in cavity；Then it is excavated every a pile, it will In the good soil dug out the directly protection stake of filling end, a pipeful of good soil of every filling, by rotary bucket when hammer ram is used, will banket rammer with strength Real, soil can arbitrarily be spread to empty periphery, but up to all compactings of the soil in cavity.Same method is by the protection of another end Stake, earth filling tamping, the protection stake at (antiaircraft tunnel) both ends empty so are just handled well in this way.

, central pile excavation earth filling tamping, central pile every is stopped using first digging to empty bottom, construct every hole, use Good soil every hole is inserted and is tamped, until ramming completely；Then the intermediate stake for jumping digging is dug again, is banketed, tamped.It so far will be complete The processing of portion's stake holes is in place.

, fabrication of reinforcing cage, the connector of pile body steel reinforcement cage vertical reinforcement is using mechanical connection or welding.Weld length is unilateral 10d, bilateral length 5d(d are bar diameter).Welding point position must mutually stagger, connector rate≤50%, and be staggered distance > 35d(d For bar diameter) and no less than 500mm.The steel reinforcement cage of sectional making, when carrying, should take appropriate measures, and prevent torsion, curved It is bent.

, intermediate pile driving construction, since centre, normal borehole is verified after pore-forming, tripping in steel reinforcement cage, concrete perfusion pile；

7, end pile driving construction, the stake of empty (antiaircraft tunnel) end of finally constructing, normal borehole are verified after pore-forming, tripping in reinforcing bar Cage, concrete perfusion pile.Thus hardly increasing cost, under conditions of not increasing the duration, completing cavity, (people's air defense is logical Road) at whole pile driving constructions.

Engineering construction case

1, project profile

Engineering name: the Shijiazhuang square Fu Li foundation pit supporting project.

Project site: construction project to be built is located on the south Shijiazhuang City people's livelihood road, builds to the west of street.

Place and local environmental conditions where engineering:

1) surrounding enviroment, scene remove and expropriation of land situation, three supplies and one leveling and the conditions such as set up.

(1) this supporting range is the Foundation Pit Construction drawing of the square Shijiazhuang Fu Li foundation pit supporting project Party A confirmation Foundation pit sprays anchor dado engineering.

(2) clear table, expropriation of land situation normally complete in place, are not necessarily to remove.

(3) construction site enclosure wall has been built in addition to east side finishes, and east side is hardening temporary road, and road can meet in place Traction engine is current.

(4) construction water electricity consumption Party A provides and plugs into a little；Has the condition of setting up of building of facing in place, worker stays and can construct It sets up to face and build in scene.

2) foundation pit hemline, foundation pit top line the permitted maximum range, bottom of foundation ditch and top absolute altitude, this supporting model Enclose is the foundation pit supporting project supporting of the Shijiazhuang square Fu Li, foundation depth 20.3m.

3) situations such as foundation pit surrounding road, load, the adjacent construction street in the adjacent people's livelihood road in foundation pit north side and east side, in place Formed dirt road can meet current load-carrying Construction traffic, as crane 25t, concrete tank 38t, bulk cement truck 100t, Reinforcing bar transport vehicle 130t, muck haulage vehicle about 25t.

4) precipitation, drainage period and requirement:

Report is surveyed in base area, this engineering level of ground water hereinafter, do not influence foundation trench earth excavation, does not need to take big in substrate Area dewatering measure can be drained using bright row's method of catchmenting.

5) the rainfall situation of base pit engineering location

Through inspection information, the Shijiazhuang City year gross precipitation of project location is 401.1-752.0mm, by factors such as extreme terrains Influence, the Annual variations of precipitation are larger, and Tendency analysis is concentrated very much, and annual precipitation is concentrated mainly on June to September, entirely The precipitation in flood season was focused mostly on again in 7,8 two month.

6) Foundation Pit Support Design service life is 1 year.

7) this programme construction content and range:

(1) support pile, stake top crown beam, anchor pole (tensioning)；

(2) reinforcing bar construction of shotcrete is hung between support pile stake；

(3) prestressed anchor is constructed；

(4) tapping pipe is arranged according to drawing requirement.

, landform, landforms and atural object overview

Proposed place is located on the south Shijiazhuang City people's livelihood road, builds to the west of street, North China Mall south 250m or so.

It is seen on regional landforms positioned at Hutuohe River alluvial-proluvial fan area.Ground elevation maximum value 71.69m, minimum value in place 69.65m, earth's surface relative relief 2.04m, landform are flatter.

, place lithology and distribution characteristics

Proposed formation is mainly rushed the Loessial silty of proluvial within the scope of 90.00m depth of exploration by miscellaneous fill, the 4th system Clay, Loessial silty clay, middle sand, silt, silty clay, medium coarse sand, silty clay, middle sand, circle gravel, silty clay, circle The composition such as gravel, cobble.Foundation is surveyed in detail reports that the engineering characteristic commentary of main foundation soil is as follows:

1) the 4th is artificial earth fill's layer (Q 4ml)

Miscellaneous fill is 1.: yellowish-brown, based on cohesive soil, silt, contains a small amount of building waste, and soil property is uneven, slightly wet, loose~slightly It is close.0.90~4.90m of thickness, layer bottom 65.75~69.92m of absolute altitude.The layer is distributed in the venue.

2) the 4th is Holocene series stack layer (Q42al+pl) recently

Loessial silty clay is 2.: yellowish-brown, contains ginger chunk, has macroporous structure, and soil property is uneven, presss from both sides loess-like silt thin layer, soft Modeling~hard.The layer has non-gravity wet collapse, and s=0.015 coefficient of collapsibility δ, collapse initial compression 199kPa, collapsibility is slight. Compressed coefficient a_1-2For 0.08~0.75MPa^-1, average out to 0.28MPa^-1, belong to low~high-compressibility foundation soil.Thickness: 0.40~ 1.90m, layer bottom absolute altitude: 66.35~68.73m.The layer is detected in individual drillings.

3) the 4th is that Holocene series rushes diluvial formation (Q4al+pl)

(1) Loessial silty clay is 3.: yellowish-brown contains ginger chunk, and soil property is uneven, presss from both sides loess-like silt thin layer, stream modeling~hard. The layer has non-gravity wet collapse, and s=0.015~0.019 coefficient of collapsibility δ, 164~196kPa of collapse initial compression, collapsibility is light It is micro-.Compressed coefficient a_1-2For 0.10~0.71MPa^-1, average out to 0.34MPa^-1, in category~high-compressibility foundation soil.Thickness: 2.60 ~6.70m, layer bottom absolute altitude: 61.06~63.37m.Place is generally distributed, and layer position is more stable.

(2) middle sand is 4.: pale yellow~canescence, feldspar, quartziferous, contains mica, disproportionately graded, part presss from both sides silt thin layer, slightly It is wet, in it is close~closely knit.Standard penetration test (SPT) actual measurement blow counts (N) is hit~37 for 22 and is hit, and average value hits for 27.7.Thickness: 1.90 ~6.10m, layer bottom absolute altitude: 57.27~60.33m.Place is generally distributed.

4) the 4th system's evening updated system punching~diluvial formation (Q3al+pl)

(1) silt is 5.: isabelline, soil property is uneven, contains mica, presss from both sides flour sand and silty clay thin layer, in it is close~closely knit, it is slightly wet~ It is wet.Compressed coefficient a_1-2For 0.17~0.44MPa^-1, average out to 0.29MPa^-1, compressible soil soil in category.Thickness: 1.20~ 4.50m, layer bottom absolute altitude: 55.21~57.74m.Place is generally distributed, and layer position is more stable.

(2) silty clay is 6.: yellowish-brown, and part presss from both sides silt thin layer, and soil property is uneven, soft modeling~hard.Compressed coefficient a_1-2 For 0.12~0.55MPa^-1, average out to 0.30MPa^-1, in category~high-compressibility foundation soil.Thickness: 3.50~6.90m, layer bottom mark It is high: 50.35~52.45m.Place is generally distributed.

(3) silty clay is 7.: yellowish-brown, contains ginger chunk, and part presss from both sides silt thin layer, and soil property is uneven, soft modeling~hard.Compression Coefficient a_1-2For 0.13~0.66MPa^-1, average out to 0.30MPa^-1, in category~high-compressibility foundation soil.Thickness: 8.60~ 12.50m, layer bottom absolute altitude: 39.01~42.35m.Place is generally distributed.

(4) medium coarse sand is 8.: brown Huang~canescence, and feldspar~quartziferous contains mica, and chiltern is purer, disproportionately graded, slightly wet, It is closely knit.Standard penetration test (SPT) actual measurement blow counts (N) value is hit for 33~61, and average out to 45.9 is hit.Thickness: 3.80~9.90m, layer bottom Absolute altitude: 32.45~37.14m.Place is generally distributed.

(5) silty clay is 9.: yellowish-brown, contains ginger chunk, and part presss from both sides clay thin layer, uniform soil quality, plastic~hard plastic.Compression system Number a_1-2For 0.12~0.42MPa^-1, average out to 0.29MPa^-1, compressible soil soil in category.Thickness: 0.70~5.70m, layer bottom Absolute altitude: 30.49~34.85m.Place is generally distributed.

(6) middle sand is (10)): brown Huang~canescence, feldspar~quartziferous contain mica, and part presss from both sides coarse sand and cobble thin layer, sand Matter is purer, disproportionately graded, slightly wet~saturation, closely knit.Standard penetration test (SPT) actual measurement blow counts (N) value is hit for 43~62, average out to 52.0 hit.Thickness (discloses thickness): 0.40~10.80m, layer (hole) bottom absolute altitude: 23.26~31.61m.Place is generally distributed.

(7) silty clay (11)_-1: yellowish-brown contains ginger chunk, and part presss from both sides cobble thin layer, and soil property is uneven, plastic~hard.Pressure Contracting coefficient a_1-2For 0.22~0.35MPa^-1, average out to 0.38MPa^-1, compressible soil soil in category.Thickness: 0.70~2.50m, Layer bottom absolute altitude: 20.95~22.79m.The layer mainly exists in the form of lenticular body in the venue.

(8) justify gravel (11): variegated, sub- round, disproportionately graded, general 2~10mm of partial size contains cobble, and maximum particle diameter is 50mm, part press from both sides medium coarse sand and cobble thin layer, and there are glued layers for this layer of Local topography, in saturation, dense state.Heavy power touching It visits to correct to hit to count and be hit for 14.8~20.5, average out to 17.8 is hit.Thickness: 6.00~14.20m, layer bottom absolute altitude: 9.62~ 18.27m.Place is generally distributed.

(9) silty clay (12): yellowish-brown contains ginger chunk, and soil property is uneven, and there are glued layer and cobbles for this layer of Local topography Interlayer, soft modeling~hard.Compressed coefficient a_1-2For 0.05~0.45MPa^-1, average out to 0.24MPa^-1, with belonging to low~middle compressibility Base soil.Thickness: 8.40~20.70m, layer bottom absolute altitude: -7.34~5.96m.Place is generally distributed.

(10) justify gravel (13): variegated, sub- round, disproportionately graded, general 5~8mm of partial size contain cobble, maximum particle diameter 60mm, Part folder medium coarse sand and cobble thin layer, there are glued layers for this layer of Local topography, in saturation, dense state.Heavy dynamic penetration is repaired Forehand number hits for 16.0~27.4, and average out to 21.3 is hit.Thickness: 1.90~13.80m, layer bottom absolute altitude: -11.54~1.33m. Area is generally distributed.

(11) cobble (14): variegated, sub- round, disproportionately graded, parent rock are medium weathering quartzite, quartzy sandstone, granite, 2~5cm of general partial size, maximum particle diameter 15cm, content 55% fills sand and a small amount of cohesive soil in 45%, in saturation, closely knit shape State.Heavy dynamic penetration amendment is hit number and is hit for 20.5~27.7, and average out to 23.8 is hit.The layer is not exposed.

, proposed place groundwater condition

Shijiazhuang Urban Districts basal water is upper Pleistocene series and Holocene series stratum, rushes proluvial ovum gravel to rush proluvial and modern age Hutuohe River The strong water-enriched layer of stone~gravel accumulation, north extend southwards by center area of Hutuohe River riverbed, under earth's surface 20.00~25.00m with Overlying strata lithology is cohesive soil, silt, sand, and following stratum is sandy gravel layer, folder cohesive soil, silt and sand, overall thickness Up to 85.00m or so.

Nineteen fifties, the long-term groundwater level depth in Shijiazhuang Urban Districts is in 6.00~7.00m or so, flood season Up to 4.00m, later since drought, industrial or agricultural and domestic consumption increase, mining of groundwater is much larger than increment, causes Shijiazhuang City underground water declines year by year, forms the Trend of Groundwater Descent Funnel centered on Shijiazhuang City industrial area.

There is surveying unit to provide data and obtains level of ground water 24.86~24.95m of absolute altitude, groundwater level depth 45.50~ 46.80m, groundwater type belong to the 4th system diving, bury relatively deep.Prospecting place year peak level often has in 8~September part, low Water level often had in 5~June, year range of stage about 1.5m.Report is surveyed in base area, this engineering level of ground water in substrate hereinafter, Foundation trench earth excavation is not influenced, does not need to take large-area precipitation measure, can be drained using bright row's method of catchmenting.

Prospecting place is residential land originally, and in the place and pollution-free source in periphery, Site Soil is not comtaminated, to construction material tool Microcorrosion.

, Foundation Pit Support Design summarize

5.1 Foundation Pit

This base pit engineering is gib, and design life is 1 year, and base hole sides safety grade is level-one.According to foundation pit depth Degree and foundation pit ambient enviroment, this engineering are divided into 1-1,2-2 totally 2 supporting sections, in which:

1-1 supporting section: supporting depth is 20.3m, and using pile-anchor retaining, five row's prestressed anchors are arranged；

2-2 supporting section: supporting depth is 20.3m, and using pile-anchor retaining, seven row's prestressed anchors are arranged；

Hole side load is wanted by that must not carry out any preloading, remaining position within foundation pit top curve 2.0m by design preloading limitation Realistic to apply, according to slope retaining depth and periphery site condition, each supporting section is reserved to be not less than 1500mm structure construction fertilizer slot.

Supporting section design parameter

This section foundation pit depth 20.3m, using pile-anchor supporting system.

Slope protection pile parameter: build-in segment length 8.7m in the long 29m of support pile, fender pile stake spacing 1.4m, stake diameter 800mm, pile body are strong Spend C25.

Crown beam parameter: doing crown beam on stake top, 6 Φ are respectively matched in crown beam size 600mm (height) × 1000 (width) arrangement of reinforcement two sides 20HRB400 grades of hot-rolled ribbed bars, intermediate Ge Jia up and down match 2 16HRB400 grades of hot-rolled ribbed bars, stirrup φ 8 200.

Flange parameter: top of the slope sets waterproof concrete aproll, width 1000mm.Concrete ejection with a thickness of 50mm, intensity C20, Interior plus 50 × 50 expanded metal lath of 1.0m wide 1mm thickness.1 14 reinforcing bar of 0.5m long φ nail is squeezed at interval of 2.0m on the outside of rainwater-proof concrete plate, And laterally be arranged 14 reinforcing rib of φ be pressed on expanded metal lath and with reinforcing bar nail welding.

Cable parameters: setting 5 row's prestressed anchors between stake, anchor pole spacing 1.4m, pore-forming aperture 150mm, and 15 degree of angle of declination, bar Body is made of Φ s15.2, intensity 1860MPa underrelaxation type prestress wire, and a centering bracket is arranged in every 1.5m.

Pouring parameter: perfusion P.S.A32.5 slag portland neat slurry, the ratio of mud 0.5~0.55, intensity M=20MPa, Using secondary splitting grouting.

Supporting parameter between stake: 6.5@200mm × 200mm steel mesh of HPB300 φ, steel mesh and soil are hung between support pile Between fixed using φ 6.5U type card, the spacing of U-shaped card is (or small with cushion block between steel mesh and slope surface to be capable of fixing mesh sheet as principle Stone) it paves, thickness of concrete cover 20mm.Lateral 1 Φ of beading, 14 reinforcing bar is set on the outside of steel mesh, it is each to be implanted into pile body two sides 100mm, longitudinal pitch 1m, then spray fine-stone concrete, and face wall thickness is not less than 50mm, intensity C20.

Pit retaining monitoring

5.3.1 monitoring project

1, surrounding building, pipeline and road settlement monitoring；

2, stake top, soil nailing wall top level and vertical displacement；

3, side Ground Subsidence Monitoring is cheated；

4, anchor axial force；

5, deeply mixing cement-soil pile.

5.3.2 walkaround inspection

1) special messenger makes an inspection tour

In the base pit engineering entire construction time, should there be special messenger to carry out walkaround inspection daily.

2) main contents of walkaround inspection

1 supporting construction

(1) supporting construction Forming Quality；

(2) whether there is or not depression, crack and slidings for the soil body after wall；

(3) foundation pit has no swell soil, quicksand, piping.

2 construction operating conditions

(1) the soil property situation of exposure and geotechnical investigation report have indifference after excavating；

(2) whether excavation of foundation pit section length and lift height are consistent with design requirement, and whether there is or not overlength, ultra-deep to excavate；

(3) whether place surface water, underground water discharge situation are normal, and whether base pit dewatering facility works well；

(4) preloading situation in ground around foundation pit, whether there is or not super heap loads.

3 foundation pit surrounding environment

(1) whether there is or not damaged, leak cases for underground piping；

(2) periphery buildings or structures have free from flaw appearance；

(3) peripheral path (ground) has free from flaw, depression；

(4) condition of construction of neighbouring foundation pit and buildings or structures.

4 monitoring facilities

(1) the intact situation of datum mark, measuring point；

(2) whether there is or not the barriers for influencing observation work；

(3) the intact and protection situation of monitoring element.

5.3.3 the method for walkaround inspection

The inspection method of walkaround inspection can be aided with the Work tools such as hammer, pricker, gage, magnifying glass and camera shooting, photography based on estimating Etc. equipment carry out.

5.3.4 walkaround inspection records

Walkaround inspection should carry out the inspection situation of natural conditions, supporting construction, construction operating condition, surrounding enviroment, monitoring facilities etc. Record in detail.It such as notes abnormalities, should notify consigner and relevant unit in time.Walkaround inspection record should arrange in time, and and instrument Device monitoring data comprehensive analysis.

5.3.5 monitoring frequency

1. different construction stages and week that the monitoring frequency of monitoring project should comprehensively consider foundation pit classification, foundation pit and underground engineering Surrounding environment, the variation of natural conditions and local experience and determine.When monitor value is relatively stable, monitoring frequency can be suitably reduced.

2. when there are following situations for the moment, Ying Tigao monitoring frequency:

(1) monitoring data reach alarming value；

(2) monitoring data change greatly or rate is accelerated；

(3) there is the not found unfavorable geology of prospecting；

(4) ultra-deep, overlength excavation etc. violate design conditions construction；

(5) the continuous rainfall of a large amount of ponding of foundation pit and periphery, long-time, municipal pipeline leak；

(6) nearby ground load increases suddenly or is more than limiting design value foundation pit；

(7) supporting construction cracks；

(8) the larger sedimentation of surrounding ground burst or the serious cracking of appearance；

(9) the larger sedimentation of adjacent building burst, differential settlement or the serious cracking of appearance；

(10) there is phenomena such as piping, leakage or drift sand in bottom of foundation ditch, side wall；

(11) construction is reorganized after base pit engineering generation accident.

5.3.6 other

1. other unaccomplished matters need to meet " architecture Foundation Pit Engineering Specifications of Monitoring Technology " (GB50497-2009) requirement.

2. owner, which should separately entrust, carries out third party with the unit of corresponding qualification and experience in addition to construction party oneself monitoring Monitoring.

Slope protection pile driving construction

5.4.1 construction process

1, preparation of construction

1) technique preparation

1. grasping the engineering geology and hydrogeologic data in place.

2. understanding slope protection pile design drawing and technical requirements, write arrangement and method for construction, confided a technological secret, raw material inspection and Concrete proportioning application.

3. understanding place and closing on the special building distribution situation base underground obstacle in area's supporting construction coverage The distribution of (old basis, underground engineering, pipeline etc.).

4. preparing working various reports, specification.

2) main plant

Original design is using steel reinforcement cage technique slotting after long spire pore-forming guncreting, the equipment that need to prepare: long-spiral drilling machine, self-unloading Concrete tank, excavator, vibrates lower cage assembly, ground pump, electric welding machine, straight thread die head threading machine, angle-bender, reinforcing bar at crane Cutting machine etc..

3) operating condition

1. reasonable Arrangement construction site, the interior barrier for influencing construction of place cleaning, low-lying place's silt or clay backfilling, reach " three supplies and one leveling ".

2. being installed to approach facility, equipment, bug check and test running, it is ensured that machinery works normally, and is equipped with enough Spare part.

3. having drawn the control point of stake position control line and horizontal elevation, safekeeping is good, and frequent repetition measurement is answered in construction.

4. raw material are marched into the arena for use, according to design requirement screwing steel bars cage.

5. pore-forming is tried before formal construction, to understand formation situation and to check selected plant construction technology Whether be suitable for.

2, construction technology

After this journey slope protection pile driving construction proposed adoption long-spiral drilling machine pore-forming guncreting anti-plug steel reinforcement cage to design stake top absolute altitude at The construction technology of stake.The technique short time limit, convenient construction, it is at low cost, it is easy to accomplish environmental protection, civilized construction.

Technology measure

1, hole location drilling is determined in measurement:

When determining hole location, according to the stake bit plan that design provides, each stake holes is required to that reliable stake position center mark is arranged Will.

Drilling:

1. carrying out the review of stake position, center tolerance < 50mm. before spudding in

2. the hole depth tolerance+300mm(that drills is not only deep shallow)

3. stake diameter deviation control in -20mm

4. vertical degree of the peg hole deviation < 1%.

5. Bored Pile Filling Coefficient is greater than 1；

Drilling machine is in place, first drill bit align piles position, then pads borer drill rod, while vertical with the good drilling rod of double plumb bob double-direction controls Degree；Hole location is checked again for after the steady drilling machine of branch, such as unqualified readjustment, qualified then steady drilling.

The depth on drilling rod should be observed in drilling.Scale or run of steel are controlled, design hole depth is drilled into, observes and do again Record easy to remember.After being drilled into bottom hole, it can be stalled after original place is dallied 5 seconds.

2, fabrication of reinforcing cage:

1. geometric dimension meets the requirements: use Mold Making to guarantee that main reinforcement position is accurate, it is good at hole perpendicularity, it is distortionless existing As geometric dimension tolerance；

(a) main reinforcement spacing ± 10mm；

(b) stirrup spacing ± 20mm；

(c) diameter ± 10mm；

(d) length ± 100mm；

2. protective device is arranged in steel reinforcement cage, it is ensured that thickness of protection tier；

3. main reinforcement protective layer thickness: main reinforcement protective layer thickness tolerance ± 20mm；

4. main reinforcement derusting, straightening, enhancing steel ring requires positive garden, and main reinforcement connector is connected using straight screw sleeve, and connector should be mutually wrong It opens, (is not less than 500mm) within the scope of the section of 35d, a reinforcing bar must not have 2 connectors, and same section connector number is not More than the 50% of main reinforcement radical；

5. reinforcing bar main reinforcement lap joint is attached using JM peel rolled straight thread connection sleeve, the processing of main reinforcement silk head, connector Group connects constructs in strict accordance with operating instruction, and silk head operator takes appointment with certificate after must be trained on qualification, and in strict accordance with training Instruction operating instruction is constructed, and before connector processing, should make 3 test specimens and process test is carried out in accordance with regulations, can apply after qualified Work.Every 500 connectors are an inspection lot in work progress, are tested.It has inspected and has filled in the inspection of steel bar head processing quality Record sheet and splice quality of connection record.

3, steel reinforcement cage is hung:

1. being lifted by crane using two point；

2. being transported with the flat car for being equipped with bracket, forbids to drag, roll, prevent steel reinforcement cage from deforming；

It is gently fallen 3. hang load hole and gently to rise, must not be pressed into, to transfer between two parties by force, guarantee verticality and protective layer thickness；

4. protective device is arranged in main reinforcement, to guarantee verticality and protective layer thickness；

5. steel reinforcement cage will be positioned strictly by design requirement, steel reinforcement cage fitting depth ± 100mm.

4, concrete perfusion:

1. perfusion fills pile using 40~60 pump pressures, the relationship for mentioning drilling speed degree and pump speed should be controlled, guarantees pile quality, prevents Fracture accident.

2., for the quality for ensuring stake top part concrete, practical influx height should be than setting when perfusion is close to stake top position Count the high 0.5m of stake top.

3. every group of stake (daily) at least does two groups of test blocks and carry out mark and support, one group of measurement its 28d intensity, one group is ready for use on measurement Short term strength, with guiding construction.

5, pile crown is cut:

After pile driving construction finishes reach design strength 70%, pile crown top laitance and any excess concrete are cut to designed elevation.

Quality assurance measure

In order to guarantee construction quality, quality control on construction, the i.e. control of drilling stage quality, reinforcing bar are carried out generally according to three phases The control of cage fabrication and installation quality, the control of steel reinforcement cage decentralization quality, quality of concreting control.

1, site localization quality

Site localization is carried out by full-time technical staff, to be checked to survey calculation result, it is ensured that can be into after accurate Row drilling machine is in place.It when drilling machine is in place, to be strictly aligned, it is ensured that the error at bit central vertical line and stake holes center is not more than 50mm.

2, drilling quality

1. borehole perpendicularity deviation allows less than 1%；

2. the drilling tool of good concentricity is used, to reduce hole deviation and perfusion fullness coefficient；

3, assembling steel reinforcement cage and alignment quality safeguard measure

1. steel reinforcement cage and core pipe and vibration hammer constitute steel reinforcement cage and be sent into system, core pipe lower end offsets with steel reinforcement cage bottom, steel reinforcement cage Top is connected with vibration hammer by ring flange.

2. wanting special messenger (2~3 people) righting under steel reinforcement cage when man-hole opening, then alignment hole center is slowly transferred steel reinforcement cage, is hung The vertical of steel reinforcement cage is kept during putting.

3. after steel reinforcement cage lower part enters concrete, slowly transferring reinforcing bar under the Gravitative Loads of steel reinforcement cage and vibration hammer first Cage opens vibration hammer after steel reinforcement cage, which is transferred to, to sink naturally, enters concrete with the control steel reinforcement cage that carries out of vibration Highly (in vibration processes, it is ensured that lift the wirerope of steel reinforcement cage always with power, tilt and be inserted into prevent steel reinforcement cage), design height is reached Stop vibration after degree, extract core pipe, in place in order to ensure steel reinforcement cage decentralization, the powerful vibration hammer of proposed adoption and rigidity are stronger The vibration-sunk device of vibration core tube composition carries out steel reinforcement cage decentralization.

4, concrete perfusion

1. to be examined or check to the qualification of Commercial Concrete producer before construction.Concrete manufacturer should provide the match ratio Shen of produced concrete Please singly, opening quotation identification, material evaluation report, the certificates of quality data such as concrete alkali chlorinity；

2. slump control prevents plugging phenomenon from occurring in 18~24cm；

3. after creeping into projected depth, drilling machine signals to ground pump signalman, with the progress of pumping, correspondingly lift drilling rod, directly Aperture is reached to concrete.

5, test plan

1. reinforcing bar: according to design requirement, all reinforcing bar former material same times march into the arena, and live former material test (60t mono- is after marching into the arena Batch), splice inspection lot is 500/batches, all 100% witnesses of test.

2. concrete: according to design requirement, this engineering uses commerical ready-mixed concrete, former material retrial, match ratio request slip, opening quotation The related datas such as identification are provided by concrete supply unit.

Steel reinforcement cage Construction Summary is inserted after long spiral press pouring concrete

After long-spiral drilling machine assembles, power head power is 150KW, and a drilling has been played in examination, discovery drilling depth or cracking, one A more hours can be at the hole of a 26.5m depth, efficiency or relatively high, and also hole is also not easy to collapse.Then problem is come, Since haze is serious, concrete at all can not be without interruption in Shijiazhuang；Another problem is to be delayed due to starting date really Fixed, high-power drill power head unloads another engineering for going into operation at once of Emergency Assistance down, has changed a 110KW power head, then Prospect hole, efficiency is very low, and 3 hours can not be at a hole, and needs repeatedly to mention brill, then lower brill.It is encountered what is more containing ginger chunk Layer position, occur beating motionless phenomenon.Construction period has tightly, haves no alternative but, and increases a rotary drilling rig.

Rotary drilling rig Construction Summary

Rotary drilling rig uses dry hole operation, an equipment, from early 6:00 to late 22:00 can 13~14 holes of pore-forming, and not Influenced by underground ginger chunk, can smooth pore-forming, also not collapse hole, concentrate concrete perfusion using time night, be utilized well The control of the concrete tank of Shijiazhuang City provides, improves efficiency, ensure that quality.But construction is to No. 120 stakes to No. 270 stakes Shi Faxian positions are just fallen in above the discarded bomb shelter in underground, and examination is found after making a hole to prevention and control hole bottom plate, hole top plate mark Height position about 3m under earth's surface, top plate are that structure, thickness about 400mm, the high about 2m in hole are built in stake, and hole bottom is brick and smears cement mortar Thin layer, bottom plate thickness about 400mm.It sends someone down to investigate on the spot later, it is found that it is more than 100 meters long North and South direction has, there are more than 50 meters to grow to toward east South Street center is built, with the at T-shaped perforation in north-south channel.It is findding out height, structure and is walking backward, beginning to pool our ideas and make concerted efforts It tries every possible means, how to break through this problem.

Opinion first is, after bomb shelter is punched on stake position, the brick formation hole wall of the people that goes down, but veto soon, First is that workload is too big, unrealistic, the time is too long, second is that too dangerous, nobody is ready down to do this work.So-called washer Stone, clay slip casting etc. again, it is clear that be unworkable.Throw away that " fly pipe " is also infeasible, a dozen just run drill bit, even if not running, It is easy to be given a discount.It discusses and tries every possible means in reinforcing steel bar cage later, sheet iron casing or thin steel pile casting can be done, be directly sleeved on reinforcing bar On cage, it is isolated this section, after completing slope protection pile, when excavation pit slowly handles protect between stake again.This method is also denied quickly, First is that processing iron sheet casing or steel pile casting are bothersome laborious, more important is be set on steel reinforcement cage even if processing, fill concrete When cannot be guaranteed quality, iron sheet casing or steel pile casting can be burst, even if broken can also flow out coagulation from protective cylinder of steel reinforcement cage upper end Soil can fill discontented.Duration does not also allow.It is finally discussing the result is that gather materials on the spot, broken the back of a tough job using existing equipment.Scene There is clay, there is rotary drilling rig, rotary bucket is exactly " hammer ram ".

Following solution has been determined, has comprised the concrete steps that: one, place is flattened, stake position is released, has fastened stake position；Two, further Trend and its both ends of empty (antiaircraft tunnel) are found out in confirmation, are respectively extended outwardly one " protection stake " at both ends, i.e., in No. 120 stakes Extend toward north, add one " protection stake ", southward extend in No. 270 stakes, adds one " protection stake ", first opened from the protection stake of one end Begin, the mound dug out is put into side, until digging this pile to the upper end in people's air defense cavity；Three, it is excavated every a pile, by what is dug out Good soil is directly inserted in the protection stake outside end, every a pipeful of good soil of filling, by rotary bucket when hammer ram use, with strength by earth filling tamping, Soil can arbitrarily be spread to empty periphery, but until the soil in cavity is all tamped.Four, same method will be outside another end " protection stake ", earth filling tamping, the stake at (antiaircraft tunnel) both ends empty so are just handled well in this way；Five, it constructs every hole, Central pile every using first dig to cavity top stop, with every hole it is good soil insert and tamp, until rammer completely until；Six, it will Centre is jumped the stake dug and is dug again, bankets, and tamps.So far in place by the processing of whole stake holes.Seven, since centre, normal borehole, at It verifies behind hole, tripping in steel reinforcement cage, concrete perfusion pile；Eight, it excavates every hole, normal borehole, verifies after same pore-forming, tripping in steel Muscle cage, concrete perfusion pile；Nine, the stake of empty (antiaircraft tunnel) two ends of finally constructing.Thus hardly increasing Cost under conditions of not increasing the duration, completes whole pile driving constructions at empty (antiaircraft tunnel).

Foundation pit site layout project horizontal displacement monitoring point 24, vertical displacement monitoring point 24, deeply mixing cement-soil pile monitoring point 8 A, anchor axial force monitoring point 27, the time foundation pit through a year and a half is whole on earth, and bottom plate of constructing, and is continuously monitored, is owned Monitoring data are in safe range, and the numerical value permitted much smaller than specification.Illustrate that the pattern foundation pit supporting structure is safe.Also demonstrate this Cavity processing be it is effective, it is economical and efficiently.

Claims (4)

1. a kind of simple and easy method of churning driven opportunity cavity pore-forming, it is characterised in that: the following steps are included:

(1), the cavity trend and tip position for needing construction area are found out, place is flattened, determines stake position；

(2), it respectively constructs one outside the both ends in the cavity of construction area and protects stake, the both ends in construction area cavity are blocked；

(3), the stake holes with the protection stake every a pile position is excavated, the good soil dug out is directly inserted in the protection stake holes of end, The a pipeful of good soil of every filling, by rotary bucket when hammer ram is used, with strength by earth filling tamping, upper 0.5~1.0m is pushed up to cavity in upper surface of banketing, Banketing can arbitrarily spread to empty periphery, but until the soil in cavity is all tamped；

(4), using the method constructed every hole, the stake holes of every pile in construction area is using first digging to absolutely empty hole, with adjacent The good soil of stake holes is inserted the stake holes and is tamped, and until ramming completely, the upper surface location that bankets is identical as step (3)；

(5), the intermediate stake holes dug of jumping is dug again, bankets, tamp, until whole pile hole constructions is completed；

(6), since the centre of construction area, the bore forming in all construction areas is completed using common process.

2. the simple and easy method of churning driven opportunity according to claim 1 cavity pore-forming, it is characterised in that: the step Suddenly in (2), the construction method of the protection stake: excavating one and banket hole to empty bottom, and bankets to tamping in cavity.

3. the simple and easy method of churning driven opportunity according to claim 1 cavity pore-forming, it is characterised in that: the step Suddenly the pile in (3) will construct every hole, avoid perforating, and stake holes can stop when digging to empty bottom end, utilize this stake holes and phase The good soil that adjacent stake holes is dug out carries out back-filling in layers, compacting；One can be provided when excavating stake holes for formal pile stable not collapse Basic condition.

4. the simple and easy method of churning driven opportunity according to claim 1 cavity pore-forming, it is characterised in that: the step Suddenly in (6), intend construction pile stake holes from centre excavate pore-forming, then successively verify, hang in steel reinforcement cage, concrete perfusion at Stake；Construction is played using jumping, it is ensured that the minimal disturbances of hole wall when pore-forming, also guarantees to rush the minimum of hole wall when concrete perfusion It hits, completes whole constructions of central pile.