Background technology
Along with The development in society and economy, demand for convenient traffic is strong further, it is also more and more to be built in various geologic bridge engineering, in bridge water in the foundation construction, extensively adopt trestle as material, equipment and personnel's construction passage, domestic trestle adopts steel pipe pile to add the frame mode of Bailey truss more.But trestle in the past generally all is built on the rivers and lake that have than thick-covering, under this geological conditions, the trestle foundation construction of leading to major project is general adopts traditional " halieutics " to carry out, be about to steel pipe pile in place after, insert by pile hammer and to beat steel pipe pile to the covering layer design elevation.But, there are a lot of rivers, lake and Marine Geology situation to be naked scar and the shallow covering layer inclination scar of tilting, as adopt conventional method to construct, because the role and influence of current, stormy waves and wind load, the anchoring of mouth can't be guaranteed at the bottom of the stable and steel pipe pile on trestle basis, thereby influences the security performance of trestle and the construction speed of major project.
At the geological condition of the precipitous naked rock of above-mentioned intectate, prior art often adopts underwater demolition, artificial covering layer, jacket, scar preexisting hole to be embedded into schemes such as steel pipe.
Underwater demolition: Wuhan-Guangzhou passenger-dedicated line emphasis Bridge Project, the depth of water 18m of place, pier position in the water, naked scar is inclined to 35 °, adopt the drilling platform scheme, at first with the scar explosion leveling of tilting, arrange the steel casing again, fill out sandbag to the riverbed upthrow and bury casing underground, rely on the existing stake of nearly Dun Chu to come stabilized platform, thereby form the drilled pile platform.This scheme needs underwater demolition, and the scarfing cinder workload is big, and the cycle is big, the cost height, and need existing stake to keep the stable of platform.
Artificial covering layer: certain Bridge Project on the Liujiang of Liuzhou, the depth of water 15m of place, pier position in the water, naked scar is inclined to 15 °, adopts the drilling platform scheme, throws at place, pier position earlier and fills out the thick earth bag of 3m, inserts and beats steel pipe pile.Artificial covering layer scheme needs to throw in flat roof area fills out a large amount of earth bags, and engineering quantity is big, the construction cost height.
Jacket: the nearly island of marine bridge, Shanghai section engineering, the bridge location sea bed is shallow covering layer and naked rock, adopting the jacket trestle is the subaqueous work passage, adopt jacket platform as the drilling platform of main pier in the water, the steel pipe with many diameter 1.1m during construction is linked to be jacket by land, and shipping is located to the pier position again, hang ship with big 1500t and hang installation, this scheme needs large-tonnage to hang ship and workboat, and steel using amount is big, and construction period is longer.
The scar preexisting hole is embedded into steel pipe: pier construction depth of water 26m in the water of Zhejiang bridge, the riverbed intectate, scar is 45 ° of inclinations, trestle, platform construction adopt preexisting hole to be embedded into the fixing constructure scheme of steel casing, namely use the percussive drill preexisting hole greater than the pile tube diameter in trestle steel pipe pile position, outside the pile tube of preexisting hole, pour into a mould underwater concrete after putting into steel pipe pile, it directly is stabilized in the rock stratum.This scheme construction period is longer, needs operation on floating platform, and water level needs more stable, and flow velocity is little.
Shortcomings such as in sum, above scheme exists all that workload is big, long construction period, cost are big.
Therefore those skilled in the art is badly in need of a kind of high-order trestle job practices and structure setting thereof that can effectively solve the connectivity problem of steel pipe pile and precipitous hard naked rock river bed, and the while can reach low, the purpose safely and efficiently of short construction period, cost.
Summary of the invention
The purpose of this utility model is according to above-mentioned the deficiencies in the prior art part, a kind of high-order trestle structure that is arranged on the precipitous naked rock of deep water torrent intectate is provided, this high position trestle structure is by cutting into mouth at the bottom of the described steel pipe pile and precipitous naked scar shape adapting on the coast, build the underwater concrete layer within it, rely on the bond stress of underwater concrete slurry and anchor pole, stake base concrete and riverbed basement rock, solve anchoring, the antiskid stable problem of steel pipe pile on precipitous hard naked rock to reach.
The utility model purpose realizes being finished by following technical scheme:
A kind of high-order trestle structure that is arranged on the precipitous naked rock of deep water torrent intectate, be specifically related to precipitous naked rock, be positioned at abutment on the bank, be positioned at bridge pier on the bank, steel pipe pile and Bailey truss, it is characterized in that bridge pier and some steel pipe piles that described high-order trestle specifically comprises the pontic of trestle and supports described pontic, fixedly connected with described pontic in described steel pipe pile top, described steel pipe pile bottom is arranged on the precipitous naked scar, be connected by the anchor pole grappling between the bottom inner chamber of described steel pipe pile and the described precipitous naked rock, and fixed being structure as a whole of underwater concrete layer by building between the three.
Degree of lip-rounding shape and described precipitous naked scar shape are suitable at the bottom of the described steel pipe pile.
The underwater concrete layer height of described steel pipe pile bottom is not less than described anchor pole and goes into the rock degree of depth.
The length of described anchor pole more than precipitous naked scar is not less than the length that it gos deep into precipitous naked rock.
Be provided with connection structure between stake between described each steel pipe pile.
The utility model has the advantages that, (1) adopt undersea detection technology and by detection data on the coast at the bottom of the precut steel pipe pile mouth make itself and precipitous naked scar suitable, safe and efficient, reduce the deep diving workload, the reduction construction risk; (2) steel pipe pile is connected employing slip casting embedding rock anchors structure with precipitous naked scar simultaneously, rely on the bond stress of underwater concrete slurry and anchor pole, stake base concrete and riverbed basement rock, so that steel pipe pile firmly is anchored on the precipitous naked scar, short construction period, cost are low, safe and efficient; (3) adopt cantilever method construction bridge, namely prior to the first hole trestle of constructing on the bank, follow-up trestle is installed Bailey truss, steel pipe pile by crawler belt loop wheel machine cantilever, and whole trestle is set up only needs a pedrail crane to cooperate, need not to employ large-scale hanging device waterborne, remarkable in economical benefits; (4) steel pipe pile is at the bank spreading, and whole long lifting puts in place, avoids weld job waterborne, reduces security risk, is conducive to the control of steel pipe pile verticality, welding quality etc.
The specific embodiment
Feature of the present utility model and other correlated characteristic are described in further detail by embodiment below in conjunction with accompanying drawing, so that technician's of the same trade understanding:
As Fig. 1-9, mark 1-27 is respectively among the figure: abutment 1, the first hole trestle 2, bridge pier 3, the second hole trestle 4, connection structure 5, steel pipe pile 6, underwater concrete layer 7, precipitous naked scar 8, checkered plates 9, vertical distribution beam 10, transverse distribution beam 11, Bailey truss 12, stake head piece 13, anchor pole 14, block 15, block rubber 16, anchor pole 17, bracing frame 18, leading truck 19, stiffening plate 20, short steel pipes stake 21, madjack pipe 22, drilling rod 23, dry-mix concrete bag 24, anchor hole 25, cement paste 26, pontic 27.
Embodiment: present embodiment is specifically related to a kind of high-order trestle structure that is arranged on the precipitous naked rock of deep water torrent intectate, and the high-order trestle structure of this kind is applicable to that deep water river, flow velocity are big, rise suddenly and sharply flood season, and mountain stream, intectate river and riverbed are precipitous or tilt hard naked rock hydrogeological conditions.Present embodiment will be that example is elaborated in conjunction with Qianjiang grand bridge engineering, and Qianjiang belongs to mountain stream, and flow is big, current are anxious, and Peak Flow Rate reaches 3.21m/s, the riverbed intectate, basement rock is middle weathering dolomite, compressive strength 80 MPa extend to the bank always, and the riverbed is precipitous in the 65m scope of offshore limit, scar is 35~53 ° of inclinations, pier place scar tilts about about 25 ° in the water, and the riverbed just rises and falls, and stalagmite stands in great numbers.For convenience the constructor enters on the bridge pier of Jiang Zhongxin and constructs, and need set up trestle towards bridge pier at both sides, river bank slope.
Be depicted as the concrete structure of high-order trestle in the present embodiment as Fig. 2,9, high-order trestle specifically comprises the pontic 27 of trestle and the steel pipe pile 6 that supports pontic 27, steel pipe pile 6 is arranged on the precipitous naked scar 8, built underwater concrete layer 7 in steel pipe pile 6 bottoms, offer the anchor hole 25 that is through to precipitous naked scar 8 inside from the upper surface of underwater concrete layer 7, be provided with simultaneously anchor pole 17 in anchor hole 25, anchor pole 17 is one by underwater concrete layer 7 anchoring of cement paste 26 and precipitous naked scar 8 inner basement rock and steel pipe pile 6 bottoms.
Shown in Fig. 1-9, below be the structure of the high-order trestle on the precipitous naked rock of deep water torrent intectate and the concrete steps of construction thereof:
1. carry out the construction of abutment 1 at first on the coast, abutment 1 can adopt inverted T shape or L type structure, and at the boring of riverbank scar and skyhook 17, the upper end of anchor pole 17 is stretched in the abutment 1, the anchoring of perfusion M35 cement mortar; At the pre-buried shaped steel in the position of Bailey truss 12 or steel plate, Bailey truss 12 is installed after, welding shaped steel restriction Bailey truss moves to, direction across bridge, vertical direction along bridge.
2. bridge pier 3 constructions on the bank, bridge pier 3 is positioned on the exposed riverbank basement rock, adopt reinforced concrete strip foundation, scar is holed on the riverbank, and skyhook stretches into strip foundation, the anchoring of perfusion M35 cement mortar, described strip foundation steel pipe pile position pre-embedded steel slab behind the concreting, is installed connection structure 5 between steel pipe pile, stake, stake head piece 13.
3. at abutment 1 and bridge pier 3 Bailey truss 12, the vertical distribution beam 10 of bridge floor, transverse distribution beam 11, checkered plates 9, railing are installed thereafter, are finished the setting up of pontic 27 of the first hole trestle 2 on the bank; On the coast next hole Bailey truss 12 to be installed is spliced into integral body, the crawler belt loop wheel machine is to the Bailey truss 12 of the middle of the river side free cantilever erection second hole trestle 4.Number row's Bailey truss 12 are spliced into the whole pontic 27 that constitutes the second hole trestle 4, the gradation rigging out, and 12 of Bailey truss bracing frame 18 is set, in order to increase the integral rigidity of bracketed part Bailey truss 12.When the second hole trestle 4 set up finish after, in its end near the middle of the river one side leading truck 19 is set, leading truck 19 adopts channel-section steels to make, and connects by bolt, and fastens on the upper and lower chord member of Bailey truss 12 by U-shaped.
4. before steel pipe pile 6 is installed, with the probe of depth-sounder and lead fixed on Metallic rod, its probe is not in underwater 30cm, along mounted leading truck 19 eight equal parts point, measure the inclination scar depth of water of precipitous naked scar 8, can determine length and the end mouth discrepancy in elevation thereof of steel pipe pile 6 according to the each point depth of water that records, on the coast the end mouth of steel pipe pile 6 is cut into and precipitous naked scar 8 shape adapting according to this end mouth discrepancy in elevation, steel pipe pile 6 is spliced by some short steel pipes stake 21 spreadings, during short steel pipes stake 21 butt joints, end face is opened groove, guarantees welding quality, simultaneously weld reinforcement plate 20 and evenly arrange along steel pipe pile 6 girths when spreading; The concrete model of wherein said underwater bathy metry instrument is the portable depth-sounder of HD-360; Install at precipitous naked scar 8 simultaneously and set up a soundd navigation and ranging, this soundd navigation and ranging can show the mode with image of scar situation under water, the concrete engineering of building that is used for the installing of follow-up steel pipe pile 6, underwater concrete layer 7 under water, check the implantation situation of steel pipe pile 6 and the situation of building of underwater concrete layer 7, replaced diver's operation.
5. select that current are steady, according to the order that is from upstream to the downstream steel pipe pile 6 be installed when flow velocity is low; According to absolute altitude at the bottom of the riverbed, at steel pipe pile 6 marks of carrying out suitable for reading, indicate direction, in order to avoid steel pipe pile 6 directions deflect behind the following water, misfit with precipitous naked scar 8; Rely on steel pipe pile 6 self gravitations, guarantee the verticality of steel pipe pile 6 by crawler belt loop wheel machine slight shift; After steel pipe pile 6 installs, confirm the implantation situation of steel pipe pile 6 by soundd navigation and ranging, simultaneously the space between the suitable for reading and leading truck 19 of steel pipe pile 6 is carved extremely with iron plate, prevent from that steel pipe pile 6 from producing to rock in follow-up construction.
6. sending diver's entry along 50cm place, the mouth outside, the end pile one circle dry-mix concrete bag 24 of steel pipe pile 6, highly is 50~80cm; Adopt vertical conduit method C30 concrete under the priming petock in steel pipe pile 6, along with concrete rises in steel pipe pile 6, concrete is under the inside and outside differential pressure effect, outwards flow out in slit between steel pipe pile 6 and precipitous naked scar 8, be filled between the dry-mix concrete bag 24, form a under water little cofferdam, simultaneously at the end of steel pipe pile 6 interruption-forming underwater concrete layer 7, the height of underwater concrete layer 7 is not less than the degree of depth of anchor pole 14 embedding rocks thereafter; During pouring underwater concrete, can utilize underwater detectoscope that the inside and outside concreting situations of steel pipe pile 6 are monitored, abnormal conditions appear or build finish after, in time arrange the diver to stake at the bottom of situation confirm to check.
7. after treating that underwater concrete layer 7 placing intensity reach 70% in the steel pipe pile 6, geological drilling rig moves to the leading truck place, in the steel pipe pile internal drilling; The drill bit of geological drilling rig is after passing through the underwater concrete layer 7 of steel pipe pile 6 bottoms, and drilling well at a slow speed prevents the drill bit sideslip; After drill bit enters competent bed 50cm, can pass through counterweight, strengthen the pressure of the drill, accelerate rate of penetration; When entering basement rock, answer core taking inspection, confirm starting point and the degree of depth of rock stratum face, in the pore forming process, when joint fissure is intensive, broken serious when the rock stratum, should take pressure injection high-strength cement slurry to make rock mass fixed earlier, treat that slurry reaches redrilling after certain intensity, until anchor hole 25 to design elevation.
8. at anchor pole 14 binding pressure-resistant plastic madjack pipes 22, madjack pipe 22 bottoms are apart from anchor pole 14 bottom 100mm, in case the pipe laying that back-silts of holing, the trestle top is stayed on the top; Drilling rod 23 by geological drilling rig is seated to anchor pole 14 in the anchor hole 25, removes the drilling rod 23 of described geological drilling rig subsequently.To compressed water slurries 26 in the anchor hole 25, when mud jacking began, the system of mixing had also been laid in cement paste 26, guaranteed the continuity of mud jacking process, after cement paste 26 stirs, with pneumatic mortar machine from plastics madjack pipe 22 to anchor hole 25 bottom mud jacking.Be the seepage that satisfies borehole anchorage section crevice water mud 26 and the water enchroachment (invasion) that prevents top water mud, the size of groundwater increment is determined by field experiment.Utilize underwater detectoscope to observe the mud jacking situation in the mud jacking process, underwater concrete layer 7 end face that cement paste 26 is depressed in the steel pipe pile 6 get final product.Carry out anchor pole 14 resistance to plucking static loading tests thereafter.
9. when steel pipe pile 6 bottom water mud 26 anchoring body compressive strength reach 70%, remove leading truck 19, steel pipe pile 6 bracing 5, a head piece 13 between each are installed; Continue the assembly unit truss to the middle of the river direction pontic 27 that the vertical distribution beam 10 of bridge floor, transverse distribution beam 11, checkered plates 9 and bridge floor railing constitute the 3rd hole trestle is installed simultaneously.
10. still be at the 3rd hole trestle tail end three leading trucks in location to be installed after, by 3. above-mentioned~in 9. same method by that analogy, until the construction of finishing the bed rearrangement trestle.
The characteristics of this high-order trestle structure and job practices thereof can be classified as following some:
(1) rise suddenly and sharply at flood season level, flow velocity is big, the riverbed is on the mountain area tachydromile of precipitous hard naked rock, adopts trestle scheme waterborne, has solved the construction access issues of pier in the water, convenient construction, save hang fare with, accelerated progress.
(2) be on the deep water river of precipitous hard naked rock in the riverbed, conventional underwater demolition and artificial covering layer technology have been broken, adopt slip casting embedding rock anchors technology to set up trestle, its construction technology is simple, the cycle is short, cost is low, has solved the connectivity problem of steel pipe pile and precipitous hard naked rock river bed safely, efficiently, reliably.
(3) trestle need not to arrange braking pier in the water, and with abutment and riverbed basement rock anchoring, opposing to horizontal force, is saved material along bridge, reduces cost.
(4) adopt cantilever method construction bridge, namely one stride trestle prior to constructing on the bank, follow-up trestle is installed Bailey truss, steel pipe pile by crawler belt loop wheel machine cantilever, and whole trestle is set up only needs a pedrail crane to cooperate, need not to employ large-scale hanging device waterborne, remarkable in economical benefits.
(5) steel pipe pile is at the bank spreading, and whole long lifting puts in place, avoids weld job waterborne, reduces security risk, is conducive to the control of steel pipe pile verticality, welding quality etc.