CN103938609B - A kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method - Google Patents

A kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method Download PDF

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CN103938609B
CN103938609B CN201410155058.3A CN201410155058A CN103938609B CN 103938609 B CN103938609 B CN 103938609B CN 201410155058 A CN201410155058 A CN 201410155058A CN 103938609 B CN103938609 B CN 103938609B
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pile
porous concrete
rubble
stake
loaded filter
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CN103938609A (en
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葛智
张宏博
孙仁娟
宋修广
黄大伟
胡益彰
王原原
魏姗姗
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Shandong University
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Shandong University
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Abstract

The invention discloses a kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method, ground external structure is rubble/sand loaded filter, inside is porous concrete, stake footpath is 0.3 ~ 0.8m, outside rubble/sand loaded filter the thickness of pile body is 0.2 ~ 0.4m, and porous concrete under water maintenance 28d compressive strength is not less than 5MPa, and transmission coefficient is not less than 5mm/s, pilespacing is 3-5 times of stake footpath, porous concrete porosity > 20%.The processing method of this ground is as follows: determine a footpath and pilespacing according to foundation settlement and requirement for bearing capacity, the thickness of the amount of filler in ground stabilization scope, reinforcement depth, pile body arrangement, stake holes, stake top granular materials or damp clay, construction pile, this ground effectively weakens the problem that porous concrete stake is blocked up by mud, rubble/sand loaded filter has played the advantage of permeable anti-filter, makes pile body can continuous and effective draining in composite foundation.

Description

A kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method
Technical field
The invention belongs to field of civil engineering, relate to a kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method.
Background technology
The composite foundation that the pile foundation of porous concrete material composition is formed can carry certain vertical load when processing soft soil foundation, there is certain bearing capacity of single pile and Bearing Capacity of Composite Foundation, porous concrete pile body can play the permeable anti-filter of discrete material in conjunction with discrete material piles such as broken stone pile and the advantage such as concrete pile intensity and toughness is large, Chinese patent CN102296593A discloses a kind of cylindrical compound concrete macadam placepile and construction technology thereof, this construction process of bored concrete pile is complicated, inner concrete is closely knit waterproof, and whole pile body drainage effect is undesirable.Chinese patent CN103452093A mentions a kind of pervious concrete broken stone pile tandem type composite foundation, because the porous concrete of new mixing is easily emanated under water environment and when vibration is constructed, cement paste and aggregate depart from cause cement paste uneven be distributed in porous concrete, blocking portion hole, makes porous concrete lose pervious function.
Replacement stone pile composite foundation pile body adopts vibration sinking tube construction to be to ensure the shaping of pile body, there is not broken pile, the disease of undergauge, the time of vibration processes can not be too short, pipe-pulling speed tube drawing process can not be too fast, tube-sinking cast-in-situ pile bore forming pipe-pulling speed should by the uniform velocity controlling, pipe-pulling speed should control at about 1.2m/min ~ 1.5m/min, when chance mud or mucky soil, pipe-pulling speed should suitably slow down, and the too much undue disturbance soil around pile of meeting that vibrates, be unfavorable for the bearing capacity of bearing capacity of single pile in composite foundation and composite foundation, vibrated many soil bodys are equivalent to outside drainage channel, smeared one deck impervious material in addition, be unfavorable for pile body draining.
Porous concrete is used as draining and is mostly to work in the fluid environment being rich in mud, and the blocking of mud can make the water permeability of the lower porous concrete of porosity have a greatly reduced quality.The blocking of porous concrete as shown in Figure 4.Iowa State University's research shows: when the porosity of porous concrete, the certain hour if porous concrete works under the fluid of composite sludge, porous concrete will lose drainage effect, as shown in Figure 5, the porous concrete specimens porosity of three kinds of porosity is respectively: 15%, 20%, 25%, inner by porous concrete specimens with the fluid being rich in silt, the fluid of each circulation fixed volume V passes through concrete, then test its transmission coefficient with clear water, transmission coefficient is as shown in ordinate in Fig. 5.Experimental result shows, when porosity comparatively large (25%) of porous concrete, the ability of opposing blocking is good, and time porosity (15%), porous concrete is substantially losing water permeability after 8 circulations.If the hole of porous concrete becomes large, then the ability of keeping out the environment being rich in slurry fluid will strengthen.In addition make porous concrete stake can the draining of continuous and effective by changing the working environment of porous concrete.Such as, if french drain rubble is anti-filter discharge structure in the road structure drainage system of Drainage Base, we can expect thus, the drainage effect of discrete material rubble/sand is better than the drainage effect of porous concrete, if apply discrete material in porous concrete stake periphery, then the anti-mud blocking ability of porous concrete stake can improve.
Summary of the invention
For solving above-mentioned the deficiencies in the prior art, the invention provides a kind of rubble/sand loaded filter-porous concrete pile composite foundation and processing method; Solve under water and Immersed tunnel cause pile body blocking and the course of work in because of sand deposit cause pile body draining inefficacy, improve pipe-pulling speed when vibration sinking tube is constructed, reduce the disturbance of soil around pile, be conducive to improving bearing capacity of single pile and Bearing Capacity of Composite Foundation, accelerate construction speed, reduce construction cost.
The technical purpose that the present invention relates to has:
Macroporosity anti-clogging does not disperse Self-leveling porous concrete to design under water; Pipe-pulling speed is improved by the mobility changing vibration sinking tube filler; Porous concrete stake week arranges rubble loaded filter, and pile body has anti-mud blocking ability; Rubble loaded filter-porous concrete pile composite foundation pile body is arranged, rubble loaded filter-porous pile composite foundation construction method.
To achieve these goals, the present invention adopts following technical scheme:
A kind of rubble/sand loaded filter-porous concrete pile composite foundation, comprise pile body, described pile body external structure is rubble/sand loaded filter, inside is porous concrete, and the diameter of pile body is 400 ~ 800mm, and the outside rubble/sand loaded filter thickness of pile body is 200 ~ 400mm, porous concrete under water maintenance 28d compressive strength is not less than 5MPa, transmission coefficient is not less than 5mm/s, and pilespacing is 3-5 times of stake footpath, porous concrete porosity > 20%.
Described pilespacing is to silt or sandy soil ground, and pilespacing is not more than 4.5 times of a footpath; Cohesive soil ground is not more than to 3 times of a footpath.
Described pile body adopts rectangle, triangle or radioactivity to arrange.
Porous concrete porosity is greater than 20%, and rubble loaded filter is laid in porous concrete periphery, makes pile body also can continuous and effective draining under the fluid environment being rich in mud, accelerates the consolidation draining of foundation soil.
A kind of porous concrete, comprises following raw material: gather materials, cement, mineral admixture, water and thickener; In mass ratio, cement and mineral admixture sum/gather materials=0.19 ~ 0.23; Described mineral admixture is SILICA FUME and nano-calcium carbonate; In mass ratio, SILICA FUME accounts for 0% ~ 10% of cement; Nano-calcium carbonate accounts for cement 0 ~ 1%, and thickener accounts for 2% ~ 4.5% of cementitious material; Gather materials for particle diameter is the graded broken stone of 5-20mm; The mass ratio of water and cementitious material is 0.25 ~ 0.35.
A preparation method for porous concrete, master operation is weigh batching and stirring, and step is as follows:
1) method of measurement: cement, water, gathers materials, SILICA FUME, and nano-calcium carbonate, thickener are measured all by mass;
2) stir: under water Large stone porous concrete adopt three-step approach carry out stirring first by gathering materials, SILICA FUME, nano-calcium carbonate, thickener and total water consumption mass ratio be 25% water mix and blend 1min; Then the water of cement and total consumption 30% is joined in mixture and stir 1min; The water being finally 45% by total consumption mass ratio adds in mixture and stirs 1min;
3) get final product discharging after stirring, transport, use; The porous concrete time of building should when concrete mixing first time the time of adding water start timing within an hour.
The processing method of above-mentioned rubble/sand loaded filter-porous concrete pile composite foundation, comprises the steps:
(1) footpath and pilespacing is determined according to foundation settlement and requirement for bearing capacity, the thickness of the amount of filler in ground stabilization scope, reinforcement depth, pile body arrangement, stake holes, stake top granular materials or damp clay;
(2) according to the parameter that step (1) obtains, in the position arranging pile body, effective leading truck will be overlapped fix, the casing length of rubble/sand and porous concrete is 1.15 times of designing pile length, the sleeve pipe of rubble/sand is squeezed in soil to predetermined reinforcement depth, then in the sleeve pipe of rubble/sand, settle the sleeve pipe of porous concrete under water, the diameter of the sleeve pipe of rubble/sand is pile body diameter, inner sleeve is porous concrete stake core diameter, porous concrete is dropped into until flush with sleeve pipe place suitable for reading at inner sleeve, outer sleeve drops into rubble/sand, condiment flushes place to sleeve pipe is suitable for reading, two sleeve pipes pull up simultaneously, vibration limit, limit tube drawing plays ground and pile, pipe-pulling speed is 3 ~ 10m/min, after pile pipe extracts ground, confirm that it binds with granular materials or damp clay after meeting designing requirement, next pile construction is carried out in telephone-moving.
The defining method of the reinforcing scope of the ground described in step (1) is as follows: reinforcing scope is greater than foundation bed area and is no less than 1 ~ 3 campshed in basic outer rim increase;
Pile body method for arranging described in step (1) is as follows: need carry out large area (﹥ 1000m 2) full hall process time, pile body adopts equilateral triangle to arrange; For single footing or strip foundation, stake position adopts rectangle, or isosceles triangle is arranged; For circular foundation or ring foundation, radioactivity is adopted to arrange.
The spacing defining method of the rubble described in step (1)/sand loaded filter porous concrete stake is as follows: pile spacing is not more than 4.5 times of rubble/sand loaded filter porous concrete stake diameter.
The defining method of the ground stabilization degree of depth described in step (1) is as follows:
1., as the buried depth ﹤ 10m of soil supporting layer, reinforcement depth is the buried depth of bearing stratum, and bearing stratum is squeezed in pile body bottom;
2., as soil supporting layer buried depth >=10m, for the engineering of Deformation control, reinforcement depth should meet the requirement that rubble/sand loaded filter-porous concrete pile composite foundation distortion is no more than structure foundation allowable strain, for the engineering controlled by stability, reinforcement depth should be greater than the degree of depth of most dangerous sliding surface;
3., in Liquefaction Foundation, reinforcement depth should adopt by the pertinent regulations of existing national standards " seismic design provision in building code " GB50011-2010;
4., stake is long can not be less than 4m, and is no more than 30m.
Stake footpath defining method described in step (1) is as follows: when adopting immersed tunnelling method pile, diameter is 0.3 ~ 0.8m, and the diameter of saturated clayey soil ground is 0.5 ~ 0.8m.
Filler method for determination of amount in stake holes described in step (1): the amount of filler in stake holes equals stake holes volume and is multiplied by fullness coefficient, and fullness coefficient gets 1.2 ~ 1.4;
The thickness of the rubble described in step (1)/sand loaded filter porous concrete stake top hardcore bed is 0.3 ~ 0.5m.
Sequence of construction described in step (2) is: should carry out in the middle of peripheral or two side direction sand foundation, should from centre to the periphery or every applying work to cohesive soil ground.
Leading truck described in step (2) is perpendicular to the ground, and vertical missing≤1.5%, pile position and design attitude deviation≤0.05m, stake footpath deviation≤0.02m, the long deviation≤0.1m of stake.
After step (2) completes, detect the construction quality of pile body, comprise following content:
(1) after construction period and construction terminate, the construction note of stake is checked; Check sleeve pipe heave amplitude and speed;
(2) detection of construction quality of pile body adopts Single Pile Load test, and adopt dynamic sounding to detect to pile body, adopt Standard piercing to inter-pile soil, static sounding, dynamic sounding or other home position testing methods detect;
(3), during ground final acceptance of construction, bearing capacity examination adopts composite foundation loading test;
(4) composite foundation loading test is no less than 5 ‰ of total amount of pile, and the Bearing Capacity of Composite Foundation testing site of each single building is no less than 3 points.
Work progress should also be noted that except observing relevant regulations stipulate following some:
1. should carry out piling experiment before formal construction, with the reasonability of demonstration test parameter, when finding to meet design requirement, relevant parameters need again be tested or change design
When 2. formally constructing, the pile pipe pipe-pulling speed that long, the pilespacing of stake that will propose in strict accordance with design, stake footpath, filler match ratio, amount of filler and test are determined and height, the construction parameters such as the operating current of motor are constructed, to guarantee to extrude the continuity of all even pile body.
Beneficial effect of the present invention:
1, pile body internal material is porous concrete, outside is rubble/sand loaded filter, rubble/sand loaded filter effectively can weaken porous concrete stake by the congestion problems of mud, and rubble/sand loaded filter has played the advantage of permeable anti-filter, makes pile body can continuous and effective draining in composite foundation.
2, in composite foundation, porous concrete is as rigid material, and rubble/sand is as discrete material, and the combination of rigid pile and granular pile has played the advantage of rigid pile, simultaneously, this porous concrete is discrete material, and yield stress own is little, and plastic viscosity is moderate, the Self-leveling character of porous concrete can provide lateral pressure for discrete material, broken pile, necking down can not be caused when pile body is constructed, vibration sinking tube pipe-pulling speed be accelerated, can 3-10m/min be promoted to; Decrease the disturbance to soil around pile, be conducive to improving bearing capacity of single pile and Bearing Capacity of Composite Foundation, porous concrete has the performance of anti-dispersion under water, can reduce the requirement to construction environment, is conducive to reducing construction cost.
3, the porous concrete of Large stone material composition is adopted, this concrete has macroporosity, and porosity communication is effective, increases one deck rubble/sand loaded filter in porous concrete periphery, thus ensure the persistence drain function of pile body, solve concrete and block the disadvantageous problem that pile body is brought.
4, the porous concrete in order to solve common new mixing does not have scour resistance under water, add anti-dispersant and nano-calcium carbonate improves concrete water mud rheological property, make the cement paste of porous concrete inside have low yield stress and suitable plastic viscosity.Thus cement paste has water resistant washes away, the surface of porous concrete aggregates can be wrapped under water environment, enhance the compliance of porous concrete to construction environment.
Accompanying drawing explanation
Fig. 1 is rubble/sand loaded filter-porous concrete stake schematic diagram;
Fig. 2 is that pile body arranges schematic diagram;
Fig. 3 is pile body arrangement form figure;
The schematic diagram of the blocking of Fig. 4 porous concrete;
Fig. 5 porous concrete blocking experiment curve;
Wherein, 1, rubble reverse osmosis layer, 2, porous concrete.
Detailed description of the invention
Below in conjunction with accompanying drawing and example, the present invention is further described.
Embodiment 1
Certain project is positioned at impact Plain, the Yellow River, belongs to areas formerly flooded by the Huanghe River.Geological condition has silt from top to bottom, clay, silt, clay.Groundwater table is at about 3m, and underground water is very abundant.For reducing settlement amount after construction, ensure the stable of building, design adopts rubble/sand loaded filter-porous concrete pile composite foundation to process soft foundation.
As shown in Figure 1, 2, a kind of rubble/sand loaded filter-porous concrete pile composite foundation, comprises pile body, and pile body outside is rubble/sand loaded filter, and rubble/sand loaded filter can stop that mud is to porous concrete stake infiltration, does not lose drainage simultaneously.Inside is porous concrete material, ensure permeable while there are certain strength and stiffness, be conducive to improving pipe-pulling speed, reduce the disturbance to soil around pile, improve the bearing capacity of composite foundation.Rubble/sand loaded filter is in conjunction with porous concrete material form compound foundation.
This basement process step is specific as follows:
Pile body adopts arranged in squares as shown in Figure 3, and according to mechanical execution condition, stake footpath is 0.5m, and long according to geological conditions stake is 9m, and the stake footpath of composite foundation is 4 times of rubble/sand loaded filter-porous concrete stake diameter; Through overtesting, this arrangement meets ground bearing capacity and meets the demands.Processing method is: determine according to site condition, and bridges and culverts ground stabilization is full hall reinforcing, reinforces area and is greater than foundation bed area and increases by 1 campshed in basic outer rim.Determined by field trial, the fullness coefficient of stake holes volume gets 1.2.Rubble/sand loaded filter filler is rubble, and mud content is less than 5%.The maximum particle of crushed stone is not more than 50mm.The hardcore bed that a layer thickness is 300mm should be laid in stake top.
Specific construction technique is: in the position arranging pile body, will overlap effective leading truck and fix; The casing length of rubble and porous concrete is 10.35m; The sleeve pipe of rubble/sand is squeezed in soil to predetermined projected depth 9m; Then in the sleeve pipe of rubble, settle the sleeve pipe of porous concrete under water, the casing length of porous concrete is also 10.35m.The diameter of rubble sleeve pipe is pile body diameter (0.5m), and inner sleeve is porous concrete stake core diameter (0.3m), and drop into porous concrete until flush with sleeve pipe place suitable for reading at inner sleeve, outer sleeve drops into rubble; Condiment flushes place to sleeve pipe is suitable for reading, and two sleeve pipes pull up simultaneously, and vibration limit, limit tube drawing goes out ground and pile; Pipe-pulling speed is 7m/min, and after pile pipe extracts ground, confirm that after it meets designing requirement to lay a layer thickness be that the hardcore bed of 300mm binds at stake top, next pile construction is carried out in telephone-moving.
In work progress, crane gear is steady, and leading truck is perpendicular to the ground, and vertical missing is for being greater than 0.8%, and pore-forming center is 30mm with designing pile center's deviation, and stake footpath Deviation Control is within 16mm, and the long deviation of stake is 34mm.Sequence of construction: undertaken by the sequence of construction at two side direction centers, beats every stake jumping every row.
After construction period and construction terminate, check the construction note of stake, check sleeve pipe reciprocating extrusion vibration number and time, sleeve pipe heave amplitude and speed, the construction notes such as each amount of filler.
The detection of construction quality of pile body is by testing Bearing Capacity of Composite Foundation, and test result is 276.1KPa, and rubble loaded filter porous concrete pile composite foundation bearing capacity is apparently higher than Loar-boaring Capacity of Composite Gravel Foundation.
The preparation of porous concrete, composition material is: gather materials, cement, mineral admixture, water and thickener.In mass ratio, (cement and mineral admixture sum)/(gathering materials)=0.23; Water/(cement and mineral admixture sum)=0.28.Described mineral admixture is SILICA FUME and nano-calcium carbonate; In mass ratio, SILICA FUME accounts for 5% of cement; Nano-calcium carbonate accounts for cement 0.5%, and thickener accounts for 3.5% of cementitious material (cement and SILICA FUME and nano-calcium carbonate sum); Gather materials for particle diameter is the rubble of 5-20mm.
Porous concrete preparation technology is: take by match ratio and gather materials, cement, SILICA FUME, nano-calcium carbonate, thickener, water, first by gathering materials, SILICA FUME, nano-calcium carbonate, thickener and total water consumption mass ratio be 25% water mix and blend 1min; Then the water of cement and total consumption 30% is joined in mixture and stir 1min; The water being finally 45% by total consumption mass ratio adds in mixture and stirs 1min; With tipping lorry, Large stone porous concrete is transported to complex ground treatment scene after stirring to construct.The time of building pile body is that concrete mixing adds water 0.5 hour that time timing starts.Field sampling makes test specimen, and sample dimensions is 15mm × 15mm × 15mm; Test specimen is carried out maintenance in standard curing and water, and its transmission coefficient and compressive strength are tested in maintenance to 28 day.The experimental result of test is in table 1.
Embodiment 2
Certain project adopts rubble/sand loaded filter-porous concrete pile composite foundation to process.
A kind of rubble/sand loaded filter-porous concrete pile composite foundation, comprise pile body, pile body outside is rubble/sand loaded filter, and rubble/sand loaded filter can stop that mud is to porous concrete stake infiltration, does not lose drainage simultaneously.Inside is porous concrete material, ensure permeable while there are certain strength and stiffness, be conducive to improving pipe-pulling speed, reduce the disturbance to soil around pile, improve the bearing capacity of composite foundation.Rubble/sand loaded filter is in conjunction with porous concrete material form compound foundation.
This basement process step is specific as follows:
Pile body adopts arranged in squares as shown in Figure 3, and according to mechanical execution condition, stake footpath is 0.3m, and long according to geological conditions stake is 4m, and the stake footpath of composite foundation is 3 times of rubble/sand loaded filter-porous concrete stake diameter; Through overtesting, this arrangement meets ground bearing capacity and meets the demands.Processing method is: determine according to site condition, and bridges and culverts ground stabilization is full hall reinforcing, reinforces area and is greater than foundation bed area and increases by 3 campsheds in basic outer rim.Determined by field trial, the fullness coefficient of stake holes volume gets 1.2.Rubble/sand loaded filter filler is rubble, mud content 4%.The maximum particle of crushed stone 45mm.The hardcore bed that a layer thickness is 0.3m should be laid in stake top.
Specific construction technique is: in the position arranging pile body, will overlap effective leading truck and fix; The casing length of rubble and porous concrete is 4.6m; The sleeve pipe of rubble/sand is squeezed in soil to predetermined projected depth 4m; Then in the sleeve pipe of rubble, settle the sleeve pipe of porous concrete under water, the casing length of porous concrete is also 4.6m.The diameter of rubble sleeve pipe is pile body diameter, and inner sleeve is porous concrete stake core diameter, and drop into porous concrete until flush with sleeve pipe place suitable for reading at inner sleeve, outer sleeve drops into rubble; Condiment flushes place to sleeve pipe is suitable for reading, and two sleeve pipes pull up simultaneously, and vibration limit, limit tube drawing goes out ground and pile; Pipe-pulling speed is 7m/min, and after pile pipe extracts ground, confirm that after it meets designing requirement to lay a layer thickness be that the hardcore bed of 0.5m binds at stake top, next pile construction is carried out in telephone-moving.
In work progress, crane gear is steady, and leading truck is perpendicular to the ground, and vertical missing is for being greater than 0.8%, and pore-forming center is 30mm with designing pile center's deviation, and stake footpath Deviation Control is within 16mm, and the long deviation of stake is 34mm.Sequence of construction: undertaken by the sequence of construction at two side direction centers, beats every stake jumping every row.
After construction period and construction terminate, check the construction note of stake, check sleeve pipe reciprocating extrusion vibration number and time, sleeve pipe heave amplitude and speed, the construction notes such as each amount of filler.
The detection of construction quality of pile body is by testing Bearing Capacity of Composite Foundation, and the bearing capacity value recording rubble loaded filter porous concrete pile composite foundation is 201.2.kpa; Rubble loaded filter porous concrete pile composite foundation bearing capacity is apparently higher than Loar-boaring Capacity of Composite Gravel Foundation.
The preparation of porous concrete, composition material is: gather materials, cement, mineral admixture, water and thickener.In mass ratio, (cement and mineral admixture sum)/(gathering materials)=0.21; Water/(cement and mineral admixture sum)=0.28.Described mineral admixture is SILICA FUME and nano-calcium carbonate; In mass ratio, SILICA FUME accounts for 5% of cement; Nano-calcium carbonate accounts for cement 0.5%, and thickener accounts for 3.5% of cementitious material (cement and SILICA FUME and nano-calcium carbonate sum); Gather materials for particle diameter is the rubble of 5-20mm.
Porous concrete preparation technology is: take by match ratio and gather materials, cement, SILICA FUME, nano-calcium carbonate, thickener, water, first by gathering materials, SILICA FUME, nano-calcium carbonate, thickener and total water consumption mass ratio be 25% water mix and blend 1min; Then the water of cement and total consumption 30% is joined in mixture and stir 1min; The water being finally 45% by total consumption mass ratio adds in mixture and stirs 1min; With tipping lorry, Large stone porous concrete is transported to complex ground treatment scene after stirring to construct.The time of building pile body is that concrete mixing adds water 0.5 hour that time timing starts.Field sampling makes test specimen, and sample dimensions is 15mm × 15mm × 15mm; Test specimen is carried out maintenance in standard curing and water, and its transmission coefficient and compressive strength are tested in maintenance to 28 day.The experimental result of test is in table 1.
Embodiment 3
Certain Project design adopts rubble/sand loaded filter-porous concrete pile composite foundation to process ground.
A kind of rubble/sand loaded filter-porous concrete pile composite foundation, comprise pile body, pile body outside is rubble/sand loaded filter, and rubble/sand loaded filter can stop that mud is to porous concrete stake infiltration, does not lose drainage simultaneously.Inside is porous concrete material, ensure permeable while there are certain strength and stiffness, be conducive to improving pipe-pulling speed, reduce the disturbance to soil around pile, improve the bearing capacity of composite foundation.Rubble/sand loaded filter is in conjunction with porous concrete material form compound foundation.
This basement process step is specific as follows:
Pile body adopts arranged in squares as shown in Figure 3, and according to mechanical execution condition, stake footpath is 0.8m, and long according to geological conditions stake is 30m, and the stake footpath of composite foundation is 5 times of rubble/sand loaded filter-porous concrete stake diameter; Through overtesting, this arrangement meets ground bearing capacity and meets the demands.Processing method is: determine according to site condition, and bridges and culverts ground stabilization is full hall reinforcing, reinforces area and is greater than foundation bed area and increases by 1 campshed in basic outer rim.Determined by field trial, the fullness coefficient of stake holes volume gets 1.4.Rubble/sand loaded filter filler is rubble, and mud content is less than 5%.The maximum particle of crushed stone is not more than 50mm.The hardcore bed that a layer thickness is 0.5m should be laid in stake top.
Specific construction technique is: in the position arranging pile body, will overlap effective leading truck and fix; The casing length of rubble and porous concrete is 34.5m; The sleeve pipe of rubble/sand is squeezed in soil to predetermined projected depth 30m; Then in the sleeve pipe of rubble, settle the sleeve pipe of porous concrete under water, the casing length of porous concrete is also 34.5m.The diameter of rubble sleeve pipe is pile body diameter, and inner sleeve is porous concrete stake core diameter, and drop into porous concrete until flush with sleeve pipe place suitable for reading at inner sleeve, outer sleeve drops into rubble; Condiment flushes place to sleeve pipe is suitable for reading, and two sleeve pipes pull up simultaneously, and vibration limit, limit tube drawing goes out ground and pile; Pipe-pulling speed is 10m/min, after pile pipe extracts ground, confirm its meet designing requirement after stake top lay a layer thickness be 0.5 hardcore bed bind, next pile construction is carried out in telephone-moving.
In work progress, crane gear is steady, and leading truck is perpendicular to the ground, and vertical missing is for being greater than 0.8%, and pore-forming center is 30mm with designing pile center's deviation, and stake footpath Deviation Control is within 16mm, and the long deviation of stake is 34mm.Sequence of construction: undertaken by the sequence of construction at two side direction centers, beats every stake jumping every row.
After construction period and construction terminate, check the construction note of stake, check sleeve pipe reciprocating extrusion vibration number and time, sleeve pipe heave amplitude and speed, the construction notes such as each amount of filler.
The detection of construction quality of pile body is by testing Bearing Capacity of Composite Foundation, and the porous concrete pile composite foundation bearing capacity value of test is 304.3kpa; Rubble loaded filter porous concrete pile composite foundation bearing capacity is apparently higher than Loar-boaring Capacity of Composite Gravel Foundation.
The preparation of porous concrete, composition material is: gather materials, cement, mineral admixture, water and thickener.In mass ratio, (cement and mineral admixture sum)/(gathering materials)=0.19; Water/(cement and mineral admixture sum)=0.28.Described mineral admixture is SILICA FUME and nano-calcium carbonate; In mass ratio, SILICA FUME accounts for 5% of cement; Nano-calcium carbonate accounts for cement 0.5%, and thickener accounts for 3.5% of cementitious material (cement and SILICA FUME and nano-calcium carbonate sum); Gather materials for particle diameter is the rubble of 5-20mm.
Porous concrete preparation technology is: take by match ratio and gather materials, cement, SILICA FUME, nano-calcium carbonate, thickener, water, first by gathering materials, SILICA FUME, nano-calcium carbonate, thickener and total water consumption mass ratio be 25% water mix and blend 1min; Then the water of cement and total consumption 30% is joined in mixture and stir 1min; The water being finally 45% by total consumption mass ratio adds in mixture and stirs 1min; With tipping lorry, Large stone porous concrete is transported to complex ground treatment scene after stirring to construct.The time of building pile body is that concrete mixing adds water 0.5 hour that time timing starts.Field sampling makes test specimen, and sample dimensions is 15mm × 15mm × 15mm; Test specimen is carried out maintenance in standard curing and water, and its transmission coefficient and compressive strength are tested in maintenance to 28 day.The experimental result of test is in table 1.
Table 1 porous concrete embodiment performance indications
By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; art technician should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (7)

1. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation, rubble/sand loaded filter-porous concrete pile composite foundation comprises pile body, described pile body external structure is rubble/sand loaded filter, inside is porous concrete, stake footpath is 0.3 ~ 0.8m, outside rubble/sand loaded filter the thickness of pile body is 0.2 ~ 0.4m, pilespacing is 3-5 times of stake footpath, porous concrete porosity > 20%, described porous concrete, comprise following raw material: gather materials, cement, mineral admixture, water and thickener, in mass ratio, cement and mineral admixture sum/gather materials=0.19 ~ 0.23, described mineral admixture is SILICA FUME and nano-calcium carbonate, in mass ratio, SILICA FUME accounts for 0% ~ 10% of cement, nano-calcium carbonate accounts for cement 0 ~ 1%, thickener accounts for 2% ~ 4.5% of cementitious material, cementitious material is cement, SILICA FUME and nano-calcium carbonate sum, gather materials for particle diameter is the graded broken stone of 5-20mm, the mass ratio of water and cementitious material is 0.25 ~ 0.35, it is characterized in that, comprise the steps:
(1) footpath and pilespacing is determined according to foundation settlement and requirement for bearing capacity, the thickness of the amount of filler in ground stabilization scope, reinforcement depth, pile body arrangement, stake holes, stake top granular materials or damp clay;
(2) according to the parameter that step (1) obtains, in the position arranging pile body, effective leading truck will be overlapped fix, the casing length of rubble/sand and porous concrete is 1.15 times of designing pile length, the sleeve pipe of rubble/sand is squeezed in soil to predetermined reinforcement depth, then in the sleeve pipe of rubble/sand, settle the sleeve pipe of porous concrete under water, the diameter of the sleeve pipe of rubble/sand is pile body diameter, inner sleeve is porous concrete stake core diameter, porous concrete is dropped into until flush with sleeve pipe place suitable for reading at inner sleeve, outer sleeve drops into rubble/sand, condiment flushes place to sleeve pipe is suitable for reading, two sleeve pipes pull up simultaneously, sleeve pipe is pulled up the pile to ground by vibration limit, limit, pipe-pulling speed is 3 ~ 10m/min, after pile pipe extracts ground, confirm that it binds with granular materials or damp clay after meeting designing requirement, next pile construction is carried out in telephone-moving.
2. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, it is characterized in that, described pilespacing is to silt or sandy soil ground, and pilespacing is not more than 4.5 times of a footpath; Cohesive soil ground is not more than to 3 times of a footpath.
3. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, is characterized in that, described pile body adopts rectangle, triangle or radioactivity to arrange.
4. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, it is characterized in that, in described step (1), the defining method of the reinforcing scope of ground is as follows: reinforcing scope is greater than foundation bed area and is no less than 1 ~ 3 campshed in basic outer rim increase;
Pile body method for arranging is as follows: processing area ﹥ 1000m 2time, pile body adopts equilateral triangle to arrange, for single footing or strip foundation, stake position adopts rectangle, or isosceles triangle is arranged, for circular foundation or ring foundation, adopts radioactivity to arrange;
The defining method of reinforcement depth is as follows
As the buried depth ﹤ 10m of soil supporting layer, reinforcement depth is the buried depth of bearing stratum, and bearing stratum is squeezed in pile body bottom; As soil supporting layer buried depth >=10m, for the engineering of Deformation control, reinforcement depth meets the requirement that composite foundation distortion is no more than structure foundation allowable strain, and for the engineering controlled by stability, reinforcement depth is greater than the degree of depth of most dangerous sliding surface; In Liquefaction Foundation, reinforcement depth should adopt by the pertinent regulations of existing national standards " seismic design provision in building code " GB50011-2010, and stake is long can not be less than 4m, and is no more than 30m;
Stake footpath defining method is as follows: when adopting immersed tunnelling method pile, diameter is 0.3 ~ 0.8m, and the diameter of saturated clayey soil ground is 0.5 ~ 0.8m;
The determination of pilespacing is as follows: to silt or sandy soil ground, and pilespacing is not more than 4.5 times of a footpath; Cohesive soil ground is not more than to 3 times of a footpath;
Filler method for determination of amount in stake holes: the amount of filler in stake holes is that stake holes volume is multiplied by fullness coefficient, and fullness coefficient gets 1.2 ~ 1.4;
The thickness of rubble/sand loaded filter porous concrete stake top granular materials or damp clay is 0.3 ~ 0.5m.
5. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, it is characterized in that, during described step (2) construction, sand foundation carries out in the middle of peripheral or two side direction, and cohesive soil ground is from centre to the periphery or every applying work.
6. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, it is characterized in that, described step (2) leading truck is perpendicular to the ground, and vertical missing≤1.5%, pile position and design attitude deviation≤0.05m, stake footpath deviation≤0.02m, the long deviation≤0.1m of stake.
7. the processing method of rubble/sand loaded filter-porous concrete pile composite foundation as claimed in claim 1, it is characterized in that, the preparation method of described porous concrete, comprises the steps:
1) each batching is weighed;
2) stir: first by gathering materials, SILICA FUME, nano-calcium carbonate, thickener and total water consumption mass ratio be 25% water mix and blend 1min; Then the water of cement and total consumption 30% is joined in mixture and stir 1min; The water being finally 45% by total consumption mass ratio adds in mixture and stirs 1min;
3) get final product discharging after stirring, transport, use.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58127823A (en) * 1982-01-25 1983-07-30 Takechi Koumushiyo:Kk Liquefaction preventive structure of foundation ground
JPS58127822A (en) * 1982-01-25 1983-07-30 Takechi Koumushiyo:Kk Liquefaction preventive structure of foundation ground
CN101234862A (en) * 2008-01-31 2008-08-06 浙江大学 Method for preparing nano modifier for cement-base material
CN102296593A (en) * 2011-05-18 2011-12-28 绍兴文理学院 Cylindrical compound bored concrete pile of concrete gravels and construction process thereof
CN103360000A (en) * 2013-06-28 2013-10-23 江苏名和集团有限公司 Pervious concrete and preparation method thereof
CN203334274U (en) * 2013-06-14 2013-12-11 盐城工学院 Novel self-draining pile

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58127823A (en) * 1982-01-25 1983-07-30 Takechi Koumushiyo:Kk Liquefaction preventive structure of foundation ground
JPS58127822A (en) * 1982-01-25 1983-07-30 Takechi Koumushiyo:Kk Liquefaction preventive structure of foundation ground
CN101234862A (en) * 2008-01-31 2008-08-06 浙江大学 Method for preparing nano modifier for cement-base material
CN102296593A (en) * 2011-05-18 2011-12-28 绍兴文理学院 Cylindrical compound bored concrete pile of concrete gravels and construction process thereof
CN203334274U (en) * 2013-06-14 2013-12-11 盐城工学院 Novel self-draining pile
CN103360000A (en) * 2013-06-28 2013-10-23 江苏名和集团有限公司 Pervious concrete and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
砂衬透水混凝土桩设计与施工;史美东等;《土工基础》;20041230;第18卷(第06期);第35页第3节 *

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