The rigid and flexible pile composite foundation that is used for the anti-soil compaction of the anti-sidesway of saturated soft soil
Technical field
The utility model relates to the building foundation technical field, is specifically related to a kind of rigid and flexible pile composite foundation for the anti-soil compaction of the anti-sidesway of saturated soft soil.Rigid pile pile body sidesway and off normal when this composite foundation can effectively prevent excavation of foundation pit when being used for enclosing and cultivating the tidal land weak soil; Can effectively reduce the pre-stress hollow tube pile construction to the soil compaction effect of surrounding buildings thing and urban operating mechanism when being used for saturated soft soil; And saving construction costs.
Background technology
In the saturated soft clay area, two kinds of stake types commonly used are bored pile and pre-stress hollow pile tube at present.To highrise building, be example (Wenzhou is typical saturated soft clay area) with area, Wenzhou, adopt bored pile foundation basically, cost height, long in time limit not only, and also mud contamination is serious; And multilayer and part small sized multiple story building, mostly adopt the prestressed pipe pile foundation, and pile for prestressed pipe is because its tangible soil compaction, unavoidably will be to closing on building and pipeline damages during construction, both made and adopted preventive action (as release aperture, anti-extrusion ditch), but in saturated soft clay area poor effect, and the density that particularly lays out pile was not almost effectively prevented extrusion method greater than 3% o'clock.Now on the one hand because the heavy economic and light environment of Construction Party, technos lacks the moderate type of foundation that not only economy is provided but also lacks soil compaction on the other hand, and making the soil compaction of pile tube destroy has become a comparatively serious social concern.
In recent years, China's Coastal Areas was from Tianjin to Zhuhai, and polder work is vigorous, was also carrying out coastal polder work as Ningbo, Zhoushan, Wenzhou of coastal area, Zhejiang.The exploitation of coastal industrial zone has become the key content of coastal local government.But at present the strand is enclosed and cultivated the district and is enclosed and cultivated the ultra-soft soil that forms the rigid pile engineering problem generally occurred when soil excavation, as stake off normal, pile body slight slope, even pile body cracking, pile body knockdown, and descends significantly to bearing capacity of single pile.This is because low, the sensitivity extra-high-speed of shear strength spy of tidal land sludge soft.Enclose and cultivate district's earth excavation pile foundation in such strand and be easy to produce earth horizontal displacement and pile body lateral force.Even the bored pile of highrise building, the engineering accident of the serious off normal of pile foundation, inclination takes place frequently, and makes that claim for eot and pile foundation reinforcement expense are very high.
The utility model content
The utility model provides a kind of rigid and flexible pile composite foundation for the anti-soil compaction of the anti-sidesway of saturated soft soil at above-mentioned the deficiencies in the prior art.
The utility model is achieved by the following technical solution:
A kind of rigid and flexible pile composite foundation for the anti-soil compaction of the anti-sidesway of saturated soft soil comprises rigid pile, flexible pile, mattress layer, concrete bed course and cushion cap, and rigid pile arranges that at the cushion cap inner ring flexible pile is the blossom type distribution around rigid pile and arranges outside rigid pile; Rigid pile is long stake; Flexible pile is stub; On rigid pile and flexible pile, construct mattress layer, concrete bed course and cushion cap.
Further setting of the present utility model is that described cushion cap is the quadrangle cushion cap; The stake footpath of described rigid pile and flexible pile is 400-1000mm, and the minimum pile spacing between rigid pile and the flexible pile is 2 times of flexible pile diameter; Described flexible pile stake is long to be 12-18 rice.
Further setting of the present utility model is that described rigid pile is pre-stress hollow pile tube or bored pile; Described flexible pile is cement mixing pile or rotary churning pile.
Further setting of the present utility model is that described mattress layer is that rubble or the slabstone of 250-350mm thickness irritated coarse sand; The c10 fine-stone concrete that described concrete bed course is 70-100mm thickness; Described cushion cap is c20-c30 steel bar concrete cushion cap.
Rigid and flexible pile composite foundation for the anti-soil compaction of the anti-sidesway of saturated soft soil described in the utility model has (stressed) characteristics of following several respects:
(1) has long stake+stub+inter-pile soil " ternary " compound action, compare with conventional pile foundation and can effectively reduce cost;
(2) long stake is king pile (rigid pile), not only carries but also load can be transmitted to the ground depths by pile body as main beaer, to reduce the compression layer distortion; Stub is time stake (flexible pile), and it mainly acts on is to reinforce weak soil between stake, can effectively reduce the rigid pile horizontal movement, and auxiliary long pile is carried; And be the basis of pile for prestressed pipe to rigid pile, because the pile tube quantity of joining of flexible pile reduces, make the density that lays out pile of pile tube much smaller than 3%, after rationally arranging construction access road, the soil compaction influence of pile tube greatly reduces, and can be reduced to rational controlled range.
Rigid and flexible pile composite foundation described in the utility model has anti-soil compaction effect to the rigidity prestressing pipe pile construction, and the saturated soft soil excavation is had the effect of anti-rigid pile sidesway; Gather the metathesis of the heavy and stub of the control of long stake simultaneously, both satisfied the requirement of intensity and distortion, reduced construction costs again, especially more obvious to preventing its advantage of engineering that the anti-sidesway of soil compaction has relatively high expectations.
Technical solutions of the utility model compare with conventional pile foundation that can to save cost about about 10%, and save the duration; Compliance is strong, the minimizing environment pollution, to multilayer, small sized multiple story building, can obviously reduce soil compaction effect, and effectively control is to surrounding environment influence; To polder weak soil and saturated ultra-soft soil, rigid pile pile body sidesway and off normal in the time of can effectively preventing excavation of foundation pit.Technical solutions of the utility model have good economic benefit and social benefit.
Description of drawings
Fig. 1 is used for the rigid and flexible pile composite foundation structure chart of the anti-soil compaction of the anti-sidesway of saturated soft soil for the utility model;
Fig. 2 is the plan view of single pile cushion cap;
Fig. 3 is the plan view of two pile caps;
Fig. 4 is the plan view of four pile caps;
Fig. 5 is the plan view of five pile caps;
Fig. 6 is the plan view of six pile caps;
Fig. 7 is the plan view of eight pile caps;
Fig. 8 is the rigid and flexible pile composite foundation static load test typical plot of the anti-soil compaction of the anti-sidesway of embodiment 1 saturated soft soil;
Fig. 9 is the rigid and flexible pile composite foundation typical case actual measurement deformation curve figure of the anti-soil compaction of the anti-sidesway of embodiment 1 saturated soft soil;
Figure 10 is that the rigid and flexible pile composite foundation building of the anti-soil compaction of the anti-sidesway of embodiment 2 saturated soft soils is arranged and neighboring buildings is arranged schematic diagram.
The specific embodiment
The utility model is described in more detail below in conjunction with the drawings and specific embodiments.
As shown in Figure 1, the utility model provides a kind of rigid and flexible pile composite foundation for the anti-soil compaction of the anti-sidesway of saturated soft soil, comprise rigid pile 1, flexible pile 2, mattress layer 4, concrete bed course and cushion cap 3, rigid pile 1 arranges that at cushion cap 3 inner rings flexible pile 2 is the blossom type distribution around rigid pile 1 and arranges outside rigid pile 1; Rigid pile 1 is long stake; Flexible pile 2 is stub; Construction mattress layer 4, concrete bed course and cushion cap 3 on rigid pile 1 and flexible pile 2, the stake end of rigid pile 1 places darker bearing stratum 5, and the stake end of flexible pile 2 places more shallow weak soil.
Wherein, described rigid pile is pre-stress hollow pile tube or bored pile; Described flexible pile is cement mixing pile or rotary churning pile; The rubble that described mattress layer thickness is 250-350mm or slabstone are irritated coarse sand; Described concrete bed course is the thick c10 fine-stone concrete of 70-100mm; Described cushion cap is c20-c30 steel bar concrete cushion cap.Described cushion cap can be the quadrangle cushion cap, can be the cushion cap of other shapes certainly; The stake footpath of described rigid pile and flexible pile is 400-1000mm, and the rigid pile pilespacing determines that by the pile foundation standard minimum pile spacing between rigid pile and the flexible pile is 2 times of flexible pile diameters; Described flexible pile stake is long to be 12-18 rice, if in this degree of depth if any grittiness interlayer soil, then grittiness interlayer soil is grown in stake.
The construction of described rigid and flexible pile should be by the construction of same pile foundation company, and requires construction cement mixing pile earlier, adopts a pile for prestressed pipe then to require flexible pile to construct can to construct in back 10 days long stake as long stake.Pile for prestressed pipe is required from the cushion cap construction earlier that may can influence surrounding building, then to constructing away from the route that is affected the building direction.Described composite foundation is applicable to saturated soft clay and encloses and cultivates the tidal land weak soil that the flexible pile materials require to add in addition the heavy SN201 additive of 0.1% cement when being used for enclosing and cultivating the tidal land weak soil.
Embodiment 1:
Certain ensures that room dwelling house A, B plot are positioned at strand, inner city, Wenzhou sheet, be close to Dong Haiwan, geology is to enclose and cultivate tidal land soil, top 2-15 rice scope soil property is ultra-soft soil (containing organic matter), underconsolidated soil, angle of internal friction is less than 4 degree, can flow away 50% in native a few minutes during shoveling in the excavator bucket, also occur landslide and serious cracking (domatic 1:2 got final product when general saturated soft soil was put the slope) when domatic 1:10 was put the slope when foundation ditch was put the slope greatly.The A plot ensures residential district, room engineering based on little high level (12-15 layer), and the bored pile of 700 long 65m of Φ is adopted in design, and bearing stratum mixes argillic horizon for the circle gravel.Foundation ditch four limits are moved back under 5 meters on the red line and are dug 5.1 meters of mean depths, find the soil excavation difficulty during construction, engineering stake off normal, pile body inclining, engineering stake off normal maximum reaches 1.2m, cause engineering to be forced to stop work, through repeatedly seeking advice from the last definite residential district construction passage employing cement mixing pile reinforcing of negotiation (about 1,500 ten thousand yuan of reinforcing expense), the part engineering stake of off normal is finished post-reinforcing (about 5,000,000 yuan of reinforcing expense) at excavation of foundation pit, and the particularity of this plot soil property causes claim for eot and place and pile foundation reinforcement expense very high.
After the experience of having drawn the A plot and lesson, the B plot (also is based on 12-15 floor height layer, the excavation of foundation pit area is similar to the A plot to the degree of depth) through recommending to have adopted the rigid and flexible pile composite foundation of the art of this patent, with (shearing) wall, the former design of cushion cap 3-6 root Φ 700 bored pile pile foundations change the rigid and flexible long-short pile composite foundation of this patent under the post, be that 2-5 root Φ 700 bored piles add the rigid and flexible pile composite foundation (layout is referring to the 2-5 pile cap figure among Fig. 2-7) that the long 15m cement mixing pile of 6-8 root Φ 500-600 is formed, the cement mixing pile of constructing earlier during enforcement (adds the heavy SN of 0.1% cement in addition
201Additive), enclose and cultivate weak soil like this and obtained effective reinforcing, after rigid pile (bored pile) construction, during soil excavation engineering stake off normal basically in allowed band, pile body do not have to tilt substantially, this engineering is considered the particularity of earthwork construction passage geology, also reinforce (about 5,000,000 yuan of reinforcing expense) as simple cement mixing pile, the small part engineering stake of off normal has also been done reinforcing (about 500,000 yuan of reinforcing expense) after excavation of foundation pit is finished.
B has adopted in the plot rigid and flexible pile composite foundation of the art of this patent, compare with the A plot, under ground portion 1 wheat harvesting period of not only saving time, and save place and about 1,500 ten thousand yuan of pile foundation reinforcement expense, adopt the rigid and flexible long-short pile composite foundation simultaneously after basis itself than former design saving cost about 10%.The static load test of 5 (rigid pile) cushion caps of this project stake the results are shown in Figure 8, and is bigger by 6% than design load; Sedimentation measured result Fig. 9 is littler by 9% than design load.
Embodiment 2:
Certain plant area is positioned at Ouhai economic development zone, Wenzhou (see figure 10), and this is planned to build plant area 2 and is provided with between the 6th floor comprehensive office buildings, a building and a building 5 floor integrated car, and its west and south are the district 1 and 5 that founds the factory.According to the exploration report that Wenzhou surveying institute provides, plan to build the place based on mud and mucky soil, belong to typical saturated soft clay.To between integrated car, the post distance is based on 6000*6000, because floor live load is bigger, 8-9 pile footpath Φ 400 is adopted in former design under the center pillar, the pre-stress hollow pile tube of the long 33m of stake, the density that lays out pile between integrated car reaches 3.3%, though this design better economy, but begin pile foundation construction in August, 2011, though adopted release aperture and ditching measure, construction was less than 5 days, and district 1 and 5(particularly plant area 5 has founded the factory), the crack has all appearred in factory building body of wall and ground drawn among the figure, under plant area 1 and 5 owners' strong interference and relevant departments' requirement, pile foundation have to stop construction between integrated car, and the rectification way of Ti Chuing had 2 kinds at that time: (1) is to continue by former figure construction, but the stake numerical control of construction every day (can only be considered 2 pile drivers at most in 4, every is controlled to be 2 of every days), because total amount of pile has 398, the duration needs 100 days, Duoed 75 days (2.5 months) than original plan, but this construction delay Construction Party is difficult to accept; (2) be to change bored pile into, but cost increase approximately 50% and also the duration than in the original plan incuring loss through delay 1.5 months, also be that the Construction Party is difficult to accept.
Finally by the rigid and flexible pile composite foundation of recommending to have adopted the art of this patent, the former design of cushion cap under standard column 8-9 root canal pile basis is changed into the rigid and flexible long-short pile composite foundation of this patent, be that 5-6 root Φ 400 long 33m pile tubes add the rigid and flexible pile composite foundation (layout is referring to 5 among Fig. 2-7 or 6 pile cap figure) that 8-10 root Φ 500 long 15m cement mixing piles are formed, in such event, pile tube between the integrated car density that lays out pile drops to 2.2%, and the pile tube total amount of pile changes 268 into.The minimizing of density and the flexibility of cement mixing pile are blocked effect because pile tube lays out pile, and the soil compaction effect of pile tube is effectively controlled, and last every day, actual 8 of the pile tubes (every is 4) of can constructing and required sequence of construction to begin direction construction northeastward by the southwest corner.Because the cement mixing pile speed of application is fast and can begin construction from northeast corner earlier, the actual pile foundation duration is 40 days, only than incuring loss through delay 15 days in the original plan, and the pile foundation cost reduces about 12% than former design, really reached and saved the relatively reasonable two Luo effects that do not influence surrounding enviroment again of cost duration, allowed this owner experience the science power of technology.
The above is preferred embodiment of the present utility model, and all equivalent variations of doing according to the utility model claim all should belong to protection domain of the present utility model.