CN107489137A - A kind of method that collapsible loess foundation is handled using cement soil padding - Google Patents
A kind of method that collapsible loess foundation is handled using cement soil padding Download PDFInfo
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- CN107489137A CN107489137A CN201710902722.XA CN201710902722A CN107489137A CN 107489137 A CN107489137 A CN 107489137A CN 201710902722 A CN201710902722 A CN 201710902722A CN 107489137 A CN107489137 A CN 107489137A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
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- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
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Abstract
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the element soil for the one layer of setting height that paved first on sub-layer, pave one layer of cement on its surface again after element soil is just flat, and ensures cement quality：Plain soil property amount=4%~10%：1；Then, shaping is carried out after cement is mixed and stirred with plain soil, is rolled, forms cement soil layer, and desired cement soil layer is met according to the more principle of the cement soil layer of the higher grade laying of the collapsible loess as ground, the laying number of plies；Finally, watering health is carried out to cement soil layer.The method that collapsible loess foundation is handled using cement soil padding of the present invention, the lime-soil cushion method that can be affected greatly in the past to environment is abandoned, relatively stable cement soil layer construction can be formed on the ground based on silt, silty clay, clay, flour sand, fine sand, effect on environment is small, a kind of effective approach is provided to solve collapsible loess foundation, beneficial effect is notable, is suitable for the application of popularization.
Description
Technical field
The present invention relates to it is a kind of using cement soil padding handle collapsible loess foundation method, in particular, especially
It is related to and a kind of cement soil padding processing settlement by soaking is utilized form improvement soil layer using a certain proportion of element soil and cement mixing
The method of loess foundation.
Background technology
China is one of country that loess distribution area is most wide in the world, and account for world's loess distribution gross area 4.9% is left
It is right.China and in the world loess distribution are most wide, thickness is maximum, the most complete country of structure, and loess cladding thickness can reach 50
~100 meters.Chinese loess is distributed mainly on Gansu, Shaanxi, Ningxia, Shanxi, the river for practising the Upper-middle Reaches of The Yellow River for claiming Loess Plateau Region
The provinces and regions such as south and Qinghai.It is located in Little Valleys In The Middle Reaches of The Yellow, the Shanxi Province of loess plateau east, accounts for the Loess Plateau gross area
24.38%.Loess is one kind of quaternary sediment, has a series of inner material composition and formalness feature, is different from
Other deposits of the same period.Under a certain pressure under (i.e. native gravity pressure or native gravity pressure and additonal pressure) loess by water
Soak, structure is destroyed rapidly and the phenomenon of significantly additional sinking occurs, referred to as saturated yielding.The settlement by soaking of loess with depth, moisture content,
The increase of dry unit weight or the reduction of void ratio and reduce, general slide rock, proluvial and the loess accumulated recently all have settlement by soaking.
Due to economic rapid growth, the implementation of national the Belt and Road strategy and Strategy of Regional, handed over for lifting
Logical transportation system modernization, improves Facilities Construction, is first developed as the highway of economic development is driven.In loessland
When area builds highway, when highway is by collapsible loess location, to ensure the safety and stability of roadbed, it is necessary to collapsible loess
Administered, collapsible loess processing method is more at present, in different areas, according to different ground soil properties and different knots
Structure thing, basement process select different processing methods.According to the experience in highway construction in recent years, the improvement side of collapsible loess
Method can use to change and fill out Sand-gravel-cushion Technioue, impact-rolling method, surface and ram method, heavy-tamping method, compacting method again（Dirt, Dense Broken Stone Peg）And pile foundation
The methods of plinth.Concrete engineering project should according to engine request, saturated yielding grade, processing depth requirements, measure condition, material source and
To surrounding environment influence etc., rational treatment measures are determined after technical economic analysis.
With the improvement of people's environmental awareness, the problem of environmental protection is also attached great importance to as engineering construction person.In the past
Handle in collapsible loess design, such as this economic, feasible measure of lime-soil cushion and environmental protection concept national at present back of the body road
Speed.It is well known that lime-soil cushion originates from Northern and Southern Dynasties' period, why so far this measures of foundation treatment still exists in engineering construction
Use.It is exactly that its intensity slowly increases with the time because lime is rammed with native mix after pressing, and with certain water stability and not
Seepage of water.But lime production has greater environmental impacts, in recent years, country is increased to environmental protection dynamics, many environmental pollutions
Serious Lime Factory is sequentially switched off so that the measure of this processing collapsible loess foundation for having a long history is examined by sternness
Test.Needed badly in engineering construction and search out a kind of economic, feasible, environmentally friendly, effective treatment measures and replace.With dampening
The extensive use of mud, the way of dirt is copied, using cement as host, gather materials on the spot, the soil body is improved, it is economical real to obtain
Handle the construction material of collapsible loess.
On using soil cement change fill out processing collapsible loess technical research it is less, most domestic is stirred using soil cement
Mix the pile bodies such as stake, rammed concrete pile processing collapsible loess foundation.Although handling collapsible loess significant effect using pile body,
But construction investment can be increased with pile body processing collapsible loess.Highway difference province is built in China Collapsible Loess District at present
There is different methods.Such as Shaanxi Province to by villages and small towns section using Sand-gravel-cushion Technioue handle, first the loess in certain depth is cut out,
Ground is rolled, compactness is not less than 90%, then uses the 3 of 0.60m with plain earthen backfill, plain soil layer top：7 dirt are closed,
Dirt is higher by original ground 0.20m, and grey soil compaction is not less than 94%；Gansu Province uses different-thickness for different grades of engineering
3：7 lime-soil cushion bed courses；As Shanxi Province is filled out at 6% rendzinas of 0.60m thickness to being changed by villages and small towns section in roadbed bottom
Reason, excavation zone backfill 6% thick rendzinases of 0.3m after excavating to roadbed.From the point of view of the collapsible loess treatment measures of current each province,
Rendzinas changes the measure that processing collapsible loess foundation still generally uses of filling out.But because country increases the protection to environment,
A large amount of underproof Lime Factories are closed down, and lime is difficult to lay in addition, and many low-quality lime are applied in engineering construction, to work
Journey produces many potential safety hazards.Up to the present, soil cement, which is applied in processing collapsible loess, successful precedent, but to it
Theoretical research lags far behind engineering practice, especially for highway Site of Collapsible Loess system application study almost
Blank.
The content of the invention
A kind of the shortcomings that present invention is in order to overcome above-mentioned technical problem, there is provided environmentally friendly utilization cement soil padding
The method for handling collapsible loess foundation.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, it is characterised in that：Held first under
The element soil for the one layer of setting height that paved on layer, pave one layer of cement on its surface again after element soil is just flat, and ensures cement quality：Element
Soil property amount=4%~10%；Then, shaping is carried out after cement is mixed and stirred with plain soil, is rolled, forms cement soil layer, and according to as ground
The more principle of the cement soil layer of the higher grade laying of the collapsible loess of base, the laying number of plies meet desired cement soil layer；
Finally, watering health is carried out to cement soil layer.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, come especially by following steps real
It is existing：
A) prepare sub-layer, first remove original ground earth's surface turf, fertile soil, then rolled, formed it is smooth, closely knit,
Without the loosely ground with weak place, and ensure that compactness, width, vertical section elevation meet design and demand of technical standard；
B) construction loftings, with total powerstation it is every 10 meters place in stake and the control stake of both sides, by the subgrade cross section figure water of design
Quasi- instrument releases the position of toe, and both sides sideline goes out 100~300cm than toe line width；Then the absolute altitude of sub-layer is measured, it is each disconnected
5 points of planar survey；
C) takes plain soil, and soil site table kind plant and tree root are all removed, and ensures that Tu Chang is met the requirements with the index of soil；
Then cut the earth using excavator, dumper transport；
D) paves plain native, first according to empty paving coefficient 1.25, the compacted depth 20cm of machine spreading, calculates paving for 25cm
Thickness；Then the area that the element soil loaded every time can be laid is calculated according to the useful load of dumper, regulation factor, uses lime
The grid of respective area delimited, to carry out uniformly unloading soil according to the lattice of per car one；
E) levelings element soil, one when unloading soil section and proceeding to 40 meters or so, is flattened roughly, Ran Houli first with bull-dozer
Quickly flattened with land leveller one time, and control the hanging wire in stake to check elevation according to both sides, by the thickness control of plain soil that paves
In the range of 24~26cm；
The water content of soil is detected in flattening course in time, is higher by water content needed for 2~3% calculating according to than optimum moisture content, such as
Fruit water content is larger, then is tedded；If water content is relatively low, moisturizing is carried out, until water content meets to require；
F) paves cement, according to 20cm compacted depth, 1.74g/cm3Maximum dry density and cement with element soil mass ratio
For the cement weight to be paved needed for the native surface of 4%~10% unit of account area element, and calculate every bag of cement puts area；In element
Sash is marked on native surface, using the uniformity that paves of sash method control cement, manually detains the method for lifting and paves cement, and utilize scraper plate
Cement is uniformly struck off and is distributed in sash；
G) is mixed and stirred, and after cement paves, is mixed uniformly with road-mixed machine rotation immediately, is mixed and stirred order and carry out from low to high, each mixes and stirs width
Degree should mix and stir overlapping more than the 30cm of width with the last time, and special messenger is set when mixing and stirring and checks water content at any time and mixes and stirs depth, is forbidden
The native interlayer of element is left in bottom, and should slightly destroy about 1cm or so underlying surfaces, so that levels bond；
H) is flattened, and first voltage stabilizing is carried out with light-duty bull-dozer after soil cement uniform mixing, with the potential out-of-flatness of exposure；Then it is sharp
Flattened with land leveller, and section is done according to middle anchoring wire hanging wire, with elevation control and horizontal slope；According to empty paving system of the land leveller essence after flat
Number is 1.10, and the cement soil thickness after essence is flat is controlled according to 22cm；
I) is rolled, and after leveling, when the water content of cement and the native compound of element is higher by 1~2% than optimum moisture content, is used immediately
Vibrated roller rolled in structure sheaf overall with, and rolling method is：First use vibrated roller static pressure one time, then road is pressed with vibration
Machine is weak to shake one time, then shakes by force again 2~3 times, last road roller static pressure one time, to eliminate surface wheelmark；
J) determines the soil cement number of plies, according to the collapsible loess grade as ground, according to " collapsible loess higher grade, institute
The soil cement number of plies of laying is more, and collapsible loess lower grade, and the soil cement number of plies laid is fewer " determine required laying
The soil cement number of plies；Under normal circumstances, the number of plies for the soil cement laid is 2~4 layers；
Repeat step d) to step i) carries out new one layer of soil cement laying, until reaching the required laying number of plies, performs step
k)；
K) healths, one layer of geotextiles are laid on soil cement surface, and carries out watering health, preserving period is no less than 7d；During health
Soil cement surface is kept to moisten all the time, before supreme structure sheaf construction, soil cement surface must cover, and must not be exposed to the sun.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, is held under the preparation described in step a)
In layer, the clear table thickness as the roadbed substrate of sub-layer be not less than 20cm, after clear table the compactness of sub-layer not less than 90%,
Compactness, width, vertical section elevation should meet subgrade construction code requirement.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the plain soil that paves described in step d)
In, the useful load of dumper is about 15m3, regulation factor takes 1.30, and the grid size of drawn grid is 5m × 9m or homalographic
Grid.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, leveling element soil described in step e)
During, when water content is larger, drying is turned using turnplow, turns and mainly carries out at noon, the whiting of earth material surface can enter
Row is next all over tedding, and during tedding, workmen checks tedding situation turnplow, it is desirable to teds on earth, avoids pressing from both sides
Layer, when there is interlayer, adjustment teds depth to notice turnplow driver in time；Testing crew tracking detects to water content, to containing
Water, which is down to, to be higher by the range of optimum moisture content 2~3%；When water content is less than optimum moisture content, preferably spilt immediately with sprinkling truck
Water, the calculation formula of rate of water make-up are：Every square of rate of water make-up=0.20 × maximum dry density × water content need to be mended；Shelving 2 after watering~
After 3 hours, whether the water content for detecting soil reaches requirement, and whether soil moisture in layer is uniform；Enter next procedure after qualified.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the cement mistake that paves described in step f)
In the case that the mass ratio of Cheng Zhong, cement and element soil is 6%, the size of drawn sash is 3m × 5m or homalographic sash, each frame
Lattice pave 6 bags of 50kg cement.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the flattening course described in step h)
In, leveling principle is：Straightway is flattened from low to high by Bian Zhizhong, curved section, forbids thin layer to make up a deficiency, should in flattening course
Absolute altitude is detected at any time, and the place of local out-of-flatness will manually turn and clear up in time floating at wheelmark in land leveller flattening course
Soil, to reduce the skin effect phenomenon of soil cement；The principle of " rather scrape and do not mend " is followed in land leveller flattening course, by leveling number control
Within three times.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the roller compaction process described in step j)
In, straight line and the horizontal curve section for not setting superelevation, rolled from both sides curb to Lu Zhizheng；If the horizontal curve section of superelevation, by interior dypass
Curb rolls shoulder laterally, wheelmark overlapping 1/2；The speed control of weak vibrated roller when shaking is in 1.5~1.7km/h, Qiang Zhenshi
The speed control of vibrated roller is in 2.0~2.5km/h；
In roller compaction process：Forbid road roller to reverse end for end or bring to a halt on section that is completed or rolling, ensure stable soil
Layer surface is not damaged；In roller compaction process, the surface of stable soil remains moistening, and as moisture evaporation is too fast, sprinkling truck is timely
Benefit spills a small amount of water, forbids to spill flood and rolls；In roller compaction process, phenomena such as if any " spring ", loose, peeling, open in time simultaneously
Mixed and stirred again after adding appropriate cement, reach quality requirement；Cement by mix, leveling punishes soil, it is necessary in cement
Complete to roll before initial set, and reach defined compaction requirement, while without obvious wheelmark.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the health process described in step k)
In, during rainy season construction, prepare the covering rain-proof utensil of enough such as plastic clothes, in case to not completing or just constructing during rainfall
Soil cement is covered in time；Often sprinkled water with sprinkling truck and carry out health, the number sprinkled water daily should be whole to support depending on weather
Remain that soil cement layer surface moistens during life；The close traffic during health, forbids heavy vehicle to pass through in addition to sprinkling truck；
Such as occur disease in preserving period, answer timely digging, be trimmed to defined requirement, the compacted depth of digging is not less than 10cm, forbidden
Thin layer subsidizes.
The method that collapsible loess foundation is handled using cement soil padding of the present invention, the processing method of transverse joint are：
The last period can reserve 5-8m without rolling after mixing and stirring shaping, and latter section is not rolled the last period when constructing part again by design
Cement amount pave cement and to be mixed and stirred together, and roller-compaction is carried out together with latter section.
The beneficial effects of the invention are as follows：The method that collapsible loess foundation is handled using cement soil padding of the present invention,
Pave plain soil and cement according to a certain percentage on sub-layer, after cement and plain soil are mixed and stirred, flattened, is being rolled, to be formed
Cement soil layer；And according to the grade of collapsible loess foundation, the cement soil layer of certain number of plies is laid, so that cement the thickness of the layer
Meet to require, finally carry out watering health, you can form cement soil layer construction.The present invention's utilizes the processing saturated yielding of cement soil padding
The method of property loess foundation, has been abandoned the lime-soil cushion method that can be affected greatly in the past to environment, has been glued with silt, silty
Soil, clay, flour sand, relatively stable cement soil layer construction can be formed on the ground based on fine sand, effect on environment is small, to solve
Collapsible loess foundation provides a kind of effective approach, and beneficial effect is notable, is suitable for the application of popularization.
Embodiment
The method that collapsible loess foundation is handled using cement soil padding of the present invention, is paved one layer on sub-layer first
The element soil of setting height, pave one layer of cement on its surface again after element soil is just flat, and ensures cement quality：Plain soil property amount=4%~
10%；Then, shaping is carried out after cement is mixed and stirred with plain soil, is rolled, forms cement soil layer, and according to the settlement by soaking as ground
The more principle of the cement soil layer of the higher grade laying of loess, the laying number of plies meet desired cement soil layer；Finally, to cement
Soil layer carries out watering health.
Soil cement construction is limited by cement earliest setting time, and work progress is the process of a continuous and compact, to construction
Organizational requirements are higher, do not allow that there was a mechanical failure in construction or because the factors such as process divergence are delayed or terminate soil cement
Construction, causes the cement setting in conditioned soil, so as to cause the failure that conditioned soil is constructed.
Realized especially by following steps：
A) prepare sub-layer, first remove original ground earth's surface turf, fertile soil, then rolled, formed it is smooth, closely knit,
Without the loosely ground with weak place, and ensure that compactness, width, vertical section elevation meet design and demand of technical standard；
In the step, the clear table thickness as the roadbed substrate of sub-layer is not less than 20cm, and the compactness of sub-layer is not after clear table
Less than 90%, compactness, width, vertical section elevation should meet subgrade construction code requirement.
B) construction loftings, with total powerstation it is every 10 meters place in stake and the control stake of both sides, by the subgrade cross section figure of design
The position of toe is released with spirit level, both sides sideline goes out 100~300cm than toe line width；Then the absolute altitude of sub-layer is measured, often
Individual 5 points of section survey；
C) takes plain soil, and soil site table kind plant and tree root are all removed, and ensures that Tu Chang is met the requirements with the index of soil；
Then cut the earth using excavator, dumper transport；
D) paves plain native, first according to empty paving coefficient 1.25, the compacted depth 20cm of machine spreading, calculates paving for 25cm
Thickness；Then the area that the element soil loaded every time can be laid is calculated according to the useful load of dumper, regulation factor, uses lime
The grid of respective area delimited, to carry out uniformly unloading soil according to the lattice of per car one；
In the step, in the described plain soil that paves, the useful load of dumper is about 15m3, regulation factor takes 1.30, institute's draw square
The grid size of net is 5m × 9m or homalographic grid.
In the case of void paving coefficient 1.25, compacted depth 20cm, useful load 15m3Dumper, the element soil of loading is every
The secondary area computation method that can pave is：15 m3 ÷1.3÷25cm=46.15 m2 ≈5m×9m。
Compacted depth in the step can be chosen between 20~30cm.
E) levelings element soil, one when unloading soil section and proceeding to 40 meters or so, is flattened roughly, so first with bull-dozer
Afterwards using land leveller quickly leveling one time, and the hanging wire in stake is controlled to check elevation according to both sides, by the thickness of plain soil that paves
Control is in the range of 24~26cm；
The water content of soil is detected in flattening course in time, is higher by water content needed for 2~3% calculating according to than optimum moisture content, such as
Fruit water content is larger, then is tedded；If water content is relatively low, moisturizing is carried out, until water content meets to require；
In the step, when water content is larger, drying is turned using turnplow, turns and mainly carries out at noon, the whiting of earth material surface
Next time can be carried out to ted, during tedding, workmen checks tedding situation turnplow, it is desirable to ted on earth,
Interlayer is avoided, when there is interlayer, adjustment teds depth to notice turnplow driver in time；Testing crew tracking is examined to water content
Survey, be down to and be higher by the range of optimum moisture content 2~3% to water content；When water content is less than optimum moisture content, preferably immediately with spilling
Waterwheel is sprinkled water, and the calculation formula of rate of water make-up is：Every square of rate of water make-up=0.20 × maximum dry density × water content need to be mended；After watering
After shelving 2~3 hours, whether the water content for detecting soil reaches requirement, and whether soil moisture in layer is uniform；Enter lower road work after qualified
Sequence.
F) paves cement, according to 20cm compacted depth, 1.74g/cm3Maximum dry density and cement with element soil matter
Amount is than the cement weight to be paved needed for the plain native surface of 4%~10% unit of account area, and calculate every bag of cement puts area；
Sash is marked on the native surface of element, the uniformity to be paved using sash method control cement, the method for lifting manually is detained and paves cement, and utilize
Cement is uniformly struck off and is distributed in sash by scraper plate；
In the step, in the case that cement is 6% with the native mass ratio of element, the size of drawn sash is 3m × 5m or homalographic frame
Lattice, each sash pave 6 bags of 50kg cement.
It is for the cement amount to be paved needed for grid that size is 3m × 5m：（3m×5m×20cm×1.74g/cm3）×
6%=313kg ≈, 6 bags × 50kg/ bags.Therefore, it is necessary to the cement for the 6 bags of 50kg that pave for 3m × 5m or the grid of equidimension.
G) is mixed and stirred, and after cement paves, is mixed uniformly with road-mixed machine rotation immediately, is mixed and stirred order and carry out from low to high, each mixes
Overlapping more than the 30cm of width should be mixed and stirred with width with the last time, and special messenger is set when mixing and stirring and checks water content at any time and mixes and stirs depth,
Forbid bottom to leave the native interlayer of element, and should slightly destroy about 1cm or so underlying surfaces, so that levels bond；
H) is flattened, and first voltage stabilizing is carried out with light-duty bull-dozer after soil cement uniform mixing, with the potential out-of-flatness of exposure；Then it is sharp
Flattened with land leveller, and section is done according to middle anchoring wire hanging wire, with elevation control and horizontal slope；According to empty paving system of the land leveller essence after flat
Number is 1.10, and the cement soil thickness after essence is flat is controlled according to 22cm；
In the step, leveling principle is：Straightway is flattened from low to high by Bian Zhizhong, curved section, forbids thin layer to make up a deficiency, whole
Absolute altitude should be detected at any time during flat, and the place of local out-of-flatness, which will manually turn and clear up in time in land leveller flattening course, takes turns
Surface dust at mark, to reduce the skin effect phenomenon of soil cement；The principle of " rather scrape and do not mend " is followed in land leveller flattening course, will be flattened
Number is controlled within three times.
I) is rolled, after leveling, when the water content of cement and the native compound of element is higher by 1~2% than optimum moisture content, immediately
Using vibrated roller roll in structure sheaf overall with, rolling method is：First with vibrated roller static pressure one time, then with vibrating
Road roller is weak to shake one time, then shakes by force again 2~3 times, last road roller static pressure one time, to eliminate surface wheelmark；
In the step, straight line and the horizontal curve section for not setting superelevation, rolled from both sides curb to Lu Zhizheng；If the horizontal curve of superelevation
Section, by inner side curb, curb rolls laterally, wheelmark overlapping 1/2；The speed control of weak vibrated roller when shaking 1.5~
1.7km/h, the speed control of vibrated roller is in 2.0~2.5km/h when shaking by force；
In roller compaction process：Forbid road roller to reverse end for end or bring to a halt on section that is completed or rolling, ensure stable soil
Layer surface is not damaged；In roller compaction process, the surface of stable soil remains moistening, and as moisture evaporation is too fast, sprinkling truck is timely
Benefit spills a small amount of water, forbids to spill flood and rolls；In roller compaction process, phenomena such as if any " spring ", loose, peeling, open in time simultaneously
Mixed and stirred again after adding appropriate cement, reach quality requirement；Cement by mix, leveling punishes soil, it is necessary in cement
Complete to roll before initial set, and reach defined compaction requirement, while without obvious wheelmark.
J) determines the soil cement number of plies, according to the collapsible loess grade as ground, according to " collapsible loess grade is got over
Height, the soil cement number of plies laid is more, and collapsible loess lower grade, and the soil cement number of plies laid is fewer " determine needed for
The soil cement number of plies of laying；Under normal circumstances, the number of plies for the soil cement laid is 2~4 layers；
Repeat step d) to step i) carries out new one layer of soil cement laying, until reaching the required laying number of plies, performs step
k)；
K) healths, one layer of geotextiles are laid on soil cement surface, and carries out watering health, preserving period is no less than 7d；During health
Soil cement surface is kept to moisten all the time, before supreme structure sheaf construction, soil cement surface must cover, and must not be exposed to the sun.
In the step, during rainy season construction, prepare the covering rain-proof utensil of enough such as plastic clothes, in case to not during rainfall
Completion or the soil cement just constructed are covered in time；Often sprinkled water with sprinkling truck and carry out health, the number sprinkled water daily should regard
Depending on weather, remain that soil cement layer surface moistens during whole health；The close traffic during health is tight in addition to sprinkling truck
Prohibit heavy vehicle to pass through；Such as occur disease in preserving period, answer timely digging, be trimmed to defined requirement, the compacted depth of digging
Not less than 10cm, thin layer is forbidden to subsidize.
The processing method of transverse joint is：The last period can reserve 5-8m without rolling after mixing and stirring shaping, latter section of construction
When the last period do not rolled to part by design cement amount pave again and cement and mix and stir together, ground together with latter section
It is molded.
Construction precautions and key control point：
1st, conscientiously carry out preliminary preparation, as construction section dropping place puts, the technical conditions of soil property property, cement performance, soil cement,
Construction equipment and its performance, technical staff and worker and weather condition etc. carry out sufficient preparation.
2nd, paying attention to teaching process control is answered in soil cement construction.Indices should be controlled to meet that construction will as strict as possible i.e. in work progress
Ask.Water content, cement dose, mix uniformity coefficient before paving thickness, mix such as plain soil and after mix, roll order and group
Conjunction form etc. all should be corrected and completed in time in work progress.
3rd, soil cement construction has much relations with temperature, to avoid the technical indicator for aggravating soil cement because of temperature difference from becoming
Change, typically preferably control and constructed under 20~25 DEG C of temperature conditionss.
4th, rolling for soil cement should be different from plain soil.I.e. soil cement answers one-shot forming under sufficient preparation, in time
Compactness index is detected, secondary ftercompction must not be carried out to the soil cement after shaping, cause soil cement structural damage.
5th, soil cement construction should follow " three fast one is closely knit " principle, i.e., quickly pave, quickly leveling, grinding compacting, quickly
The method of detection, to ensure that whole work progress is completed before cement initial set.
6th, it is secondary mix and stir before must detect water content and according to must rate of water make-up carry out moisture content supplement so that mix and stir rear cement
Soil is rolled in the case of being slightly above 1-2 percentage points of optimum moisture content, can so reduce surface peeling phenomenon.
7th, the principle of " rather scrape and do not mend " is followed in land leveller flattening course, by leveling number control within three times, and
Absolute altitude reaches code requirement.In land leveller flattening course, strictly to control section absolute altitude and strike off depth, forbid thin layer to look for
Mend.
8th, the watering maintenance during health is paid attention to, the moistening on soil cement surface during ensureing to conserve.
Claims (10)
- A kind of 1. method that collapsible loess foundation is handled using cement soil padding, it is characterised in that：Spread out first on sub-layer The element soil of one layer of setting height of paving, pave one layer of cement on its surface again after element soil is just flat, and ensures cement quality：Plain soil property amount =4%~10%；Then, shaping is carried out after cement is mixed and stirred with plain soil, is rolled, forms cement soil layer, and according to as the wet of ground The more principle of the cement soil layer of the higher grade laying of property loess is fallen into, the laying number of plies meets desired cement soil layer；Finally, it is right Cement soil layer carries out watering health.
- 2. the method according to claim 1 that collapsible loess foundation is handled using cement soil padding, it is characterised in that tool Body is realized by following steps：A) prepare sub-layer, first remove original ground earth's surface turf, fertile soil, then rolled, formed it is smooth, closely knit, Without the loosely ground with weak place, and ensure that compactness, width, vertical section elevation meet design and demand of technical standard；B) construction loftings, with total powerstation it is every 10 meters place in stake and the control stake of both sides, by the subgrade cross section figure water of design Quasi- instrument releases the position of toe, and both sides sideline goes out 100~300cm than toe line width；Then the absolute altitude of sub-layer is measured, it is each disconnected 5 points of planar survey；C) takes plain soil, and soil site table kind plant and tree root are all removed, and ensures that Tu Chang is met the requirements with the index of soil； Then cut the earth using excavator, dumper transport；D) paves plain native, first according to empty paving coefficient 1.25, the compacted depth 20cm of machine spreading, calculates paving for 25cm Thickness；Then the area that the element soil loaded every time can be laid is calculated according to the useful load of dumper, regulation factor, uses lime The grid of respective area delimited, to carry out uniformly unloading soil according to the lattice of per car one；E) levelings element soil, one when unloading soil section and proceeding to 40 meters or so, is flattened roughly, Ran Houli first with bull-dozer Quickly flattened with land leveller one time, and control the hanging wire in stake to check elevation according to both sides, by the thickness control of plain soil that paves In the range of 24~26cm；The water content of soil is detected in flattening course in time, is higher by water content needed for 2~3% calculating according to than optimum moisture content, such as Fruit water content is larger, then is tedded；If water content is relatively low, moisturizing is carried out, until water content meets to require；F) paves cement, according to 20cm compacted depth, 1.74g/cm3Maximum dry density and cement and element soil mass ratio be The cement weight to be paved needed for the native surface of 4%~10% unit of account area element, and calculate every bag of cement puts area；In plain soil Sash is marked on surface, using the uniformity that paves of sash method control cement, manually detains the method for lifting and paves cement, and will using scraper plate Cement uniformly strikes off and is distributed in sash；G) is mixed and stirred, and after cement paves, is mixed uniformly with road-mixed machine rotation immediately, is mixed and stirred order and carry out from low to high, each mixes and stirs width Degree should mix and stir overlapping more than the 30cm of width with the last time, and special messenger is set when mixing and stirring and checks water content at any time and mixes and stirs depth, is forbidden The native interlayer of element is left in bottom, and should slightly destroy about 1cm or so underlying surfaces, so that levels bond；H) is flattened, and first voltage stabilizing is carried out with light-duty bull-dozer after soil cement uniform mixing, with the potential out-of-flatness of exposure；Then it is sharp Flattened with land leveller, and section is done according to middle anchoring wire hanging wire, with elevation control and horizontal slope；According to empty paving system of the land leveller essence after flat Number is 1.10, and the cement soil thickness after essence is flat is controlled according to 22cm；I) is rolled, and after leveling, when the water content of cement and the native compound of element is higher by 1~2% than optimum moisture content, is used immediately Vibrated roller rolled in structure sheaf overall with, and rolling method is：First use vibrated roller static pressure one time, then road is pressed with vibration Machine is weak to shake one time, then shakes by force again 2~3 times, last road roller static pressure one time, to eliminate surface wheelmark；J) determines the soil cement number of plies, according to the collapsible loess grade as ground, according to " collapsible loess higher grade, institute The soil cement number of plies of laying is more, and collapsible loess lower grade, and the soil cement number of plies laid is fewer " determine required laying The soil cement number of plies；Under normal circumstances, the number of plies for the soil cement laid is 2~4 layers；Repeat step d) to step i) carries out new one layer of soil cement laying, until reaching the required laying number of plies, performs step k)；K) healths, one layer of geotextiles are laid on soil cement surface, and carries out watering health, preserving period is no less than 7d；During health Soil cement surface is kept to moisten all the time, before supreme structure sheaf construction, soil cement surface must cover, and must not be exposed to the sun.
- 3. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：In preparation sub-layer described in step a), the clear table thickness as the roadbed substrate of sub-layer is not less than 20cm, after clear table The compactness of sub-layer is not less than 90%, and compactness, width, vertical section elevation should meet subgrade construction code requirement.
- 4. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：In the plain soil that paves described in step d), the useful load of dumper is about 15m3, regulation factor takes 1.30, drawn grid Grid size be 5m × 9m or homalographic grid.
- 5. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：During leveling element soil described in step e), when water content is larger, drying is turned using turnplow, is turned mainly in Noon is carried out, and the whiting of earth material surface can carry out next time and ted, and during tedding, workmen is carried out turnplow to tedding situation Check, it is desirable to ted on earth, avoid interlayer, when there is interlayer, adjustment teds depth to notice turnplow driver in time；Testing crew with Track detects to water content, is down to and is higher by the range of optimum moisture content 2~3% to water content；When water content is aqueous less than optimal During amount, sprinkler is preferably used immediately, and the calculation formula of rate of water make-up is：Every square of rate of water make-up=0.20 × maximum dry density × need Mend water content；Shelving is after 2~3 hours after watering, and whether the water content for detecting soil reaches requirement, and whether soil moisture in layer is uniform； Enter next procedure after qualified.
- 6. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：During the cement that paves described in step f), in the case that cement is 6% with the native mass ratio of element, the size of drawn sash is 3m × 5m or homalographic sash, each sash pave 6 bags of 50kg cement.
- 7. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：In flattening course described in step h), leveling principle is：Straightway is flattened from low to high by Bian Zhizhong, curved section, sternly Prohibit thin layer to make up a deficiency, absolute altitude should be detected in flattening course at any time, the place of local out-of-flatness will manually turn and clear up level land in time Surface dust in machine flattening course at wheelmark, to reduce the skin effect phenomenon of soil cement；Follow and " rather scrape not in land leveller flattening course The principle of benefit ", leveling number is controlled within three times.
- 8. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：In roller compaction process described in step i), straight line and the horizontal curve section for not setting superelevation, rolled from both sides curb to Lu Zhizheng； If the horizontal curve section of superelevation, by inner side curb, curb rolls laterally, wheelmark overlapping 1/2；The speed of weak vibrated roller when shaking Control in 1.5~1.7km/h, the speed control of vibrated roller is in 2.0~2.5km/h when shaking by force；In roller compaction process：Forbid road roller to reverse end for end or bring to a halt on section that is completed or rolling, ensure stable soil Layer surface is not damaged；In roller compaction process, the surface of stable soil remains moistening, and as moisture evaporation is too fast, sprinkling truck is timely Benefit spills a small amount of water, forbids to spill flood and rolls；In roller compaction process, phenomena such as if any " spring ", loose, peeling, open in time simultaneously Mixed and stirred again after adding appropriate cement, reach quality requirement；Cement by mix, leveling punishes soil, it is necessary in cement Complete to roll before initial set, and reach defined compaction requirement, while without obvious wheelmark.
- 9. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：During health described in step k), during rainy season construction, prepare the covering rain-proof utensil of enough such as plastic clothes, with Make preparation for dropping rain when the soil cement that does not complete or just construct is covered in time；Often sprinkled water with sprinkling truck and carry out health, spilt daily The number of water should remain that soil cement layer surface moistens depending on weather during whole health；The close traffic during health, Heavy vehicle is forbidden to pass through in addition to sprinkling truck；Such as occur disease in preserving period, answer timely digging, be trimmed to defined requirement, dig The compacted depth of benefit is not less than 10cm, forbids thin layer to subsidize.
- 10. the method according to claim 1 or 2 that collapsible loess foundation is handled using cement soil padding, its feature are existed In：The processing method of transverse joint is：The last period can reserve 5-8m without rolling after mixing and stirring shaping, before latter section is incited somebody to action when constructing One section is not rolled part and by design cement amount pave again and cement and mixes and stirs together, is rolled into together with latter section Type.
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| CN113622242A (en) * | 2021-08-18 | 2021-11-09 | 中电建十一局工程有限公司 | Rapid construction method for filling cement soil |
| CN114016342A (en) * | 2021-09-24 | 2022-02-08 | 山东高速集团有限公司 | Roadbed and pavement balance design method and structure |
| CN114059563A (en) * | 2021-11-09 | 2022-02-18 | 中铁八局集团第七工程有限公司 | Multi-material layered filling method |
| CN115125956A (en) * | 2022-07-01 | 2022-09-30 | 上海宝冶集团有限公司 | Construction method for replacing and filling foundation with cement for photoelectron standard factory building |
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