CN213804677U - Soft soil foundation structure - Google Patents

Soft soil foundation structure Download PDF

Info

Publication number
CN213804677U
CN213804677U CN202022424307.8U CN202022424307U CN213804677U CN 213804677 U CN213804677 U CN 213804677U CN 202022424307 U CN202022424307 U CN 202022424307U CN 213804677 U CN213804677 U CN 213804677U
Authority
CN
China
Prior art keywords
soft soil
foundation
box
soil foundation
weight
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202022424307.8U
Other languages
Chinese (zh)
Inventor
金建鸿
杨仲轩
王金昌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN202022424307.8U priority Critical patent/CN213804677U/en
Application granted granted Critical
Publication of CN213804677U publication Critical patent/CN213804677U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

The application discloses soft soil foundation structure. The soft soil foundation structure comprises a soft soil foundation, a box type foundation and a roadbed, wherein the soft soil foundation is provided with a groove, the box type foundation is arranged in the groove and is of a hollow structure, the roadbed covers the upper surface of the box type foundation, and the sum of the weight of the roadbed, the weight borne by the roadbed and the weight of the box type foundation is equal to the weight of soft soil dug out of the groove part of the soft soil foundation. The utility model discloses a soft soil foundation structure can eliminate the additional stress of road bed to soft soil foundation for the road bed does not produce vertical settlement, and box basis also can regard as the utility tunnel in the ground to use, make full use of underground space.

Description

Soft soil foundation structure
Technical Field
The utility model relates to a civil engineering technical field especially relates to a soft soil foundation structure.
Background
Wide soft soil is distributed in coastal areas of China, and the soft soil has the characteristics of high natural water content, large pore ratio, high compressibility, low shear strength and the like. Referring to fig. 1, as for the natural soft soil foundation 101, because the surface 102 has no load, the self-weight stress distribution curve 103 of the soft soil foundation 101 is reasonably distributed, and the soft soil foundation 101 does not generate vertical settlement under the self-weight stress. When a roadbed is constructed in a soft soil area, please refer to fig. 2, the roadbed 203 with a certain height is filled on the surface 202 of the soft soil foundation 201, the self-weight stress distribution curve 204 of the soft soil is distributed as shown in the figure, because the soft soil has high compressibility, under the action of the load of the roadbed 203, additional stress can be generated in the soft soil foundation 201, the additional stress curve 205 is distributed as shown in the figure, the soft soil foundation 201 can generate vertical settlement, and excessive vertical settlement can generate a plurality of adverse effects on the road. Therefore, the soft soil foundation needs to be treated in the design stage, so that the settlement of the treated roadbed is controlled within the standard allowable range.
At present, the methods for treating soft soil subgrade mainly comprise three types: drainage consolidation method, composite foundation method and light embankment method. The drainage consolidation method is characterized in that under the action of the self weight of a road subgrade, pore water in soil is slowly drained by arranging a vertical drainage well (a sand well or a plastic drainage bag and the like), the soft foundation is gradually consolidated, and the soft foundation is settled; along with the gradual dissipation of the hyperstatic pore water pressure of the soil body, the effective stress of the soil body is gradually increased, the shear strength of the foundation is gradually increased, and the settlement is advanced or the settlement rate is increased so as to achieve the purpose of reducing the settlement of the roadbed in the use stage of the roadbed. The composite foundation method is that part of soil body of the natural foundation is enhanced or replaced in the foundation treatment process, or a reinforcement body is arranged in the natural foundation, the natural foundation soil body and the reinforcement body form an artificial foundation which jointly bears the upper load, and cement mixing piles, high-pressure jet grouting piles, prestressed pipe piles and the like are commonly adopted in road engineering to treat the soft foundation so as to achieve the purpose of reducing subgrade settlement; the light embankment method uses light materials such as foam concrete, EPS and the like as roadbed fillers to reduce the self weight of the roadbed, thereby achieving the purpose of reducing settlement. The composite foundation method and the light embankment method can reduce subgrade settlement to a certain degree, but cannot radically eliminate the subgrade settlement, and the subgrade settlement is large especially for deep soft soil foundations (foundations with the soft soil buried depth of 20-40 m).
SUMMERY OF THE UTILITY MODEL
The utility model provides a to above-mentioned problem, a soft soil foundation structure is proposed, can eliminate the additional stress of road bed to soft soil foundation for the road bed does not produce vertical settlement, and box basis also can regard as the utility tunnel use in the underground, make full use of underground space.
The utility model adopts the following technical scheme: the utility model provides a soft soil foundation structure, including soft soil foundation, box basis and road bed, the soft soil foundation is equipped with the slot, box basis is located the ditch inslot, box basis is hollow structure, the road bed cover in the upper surface of box basis, the weight of road bed the weight that the road bed bore and the weight sum of box basis with the soft soil weight that the slot part of soft soil foundation was dug out equals.
In an embodiment of the utility model, soft soil foundation structure still includes the baffle, the baffle is located in the box basis, the baffle will a plurality of compartment chambeies are separated into on the box basis to strengthen the structural strength on box basis.
In an embodiment of the present invention, the partition plates include a plurality of longitudinal partition plates parallel to each other and a plurality of transverse partition plates parallel to each other, and the longitudinal partition plates are perpendicular to the transverse partition plates; the longitudinal clapboards and the transverse clapboards are arranged at equal intervals.
In an embodiment of the present invention, the upper surface of the box-type foundation is higher than the surface layer of the soft soil foundation by 0.30 to 0.70 m.
In an embodiment of the present invention, the box-type foundation is a reinforced concrete box.
In an embodiment of the present invention, the cross section of the roadbed is trapezoidal, and the slope ratio of the roadbed is 1: 1.5; the cross section of the box-type foundation is rectangular.
The utility model has the advantages that: the utility model provides a soft soil foundation structure, including the soft soil foundation, box basis and road bed, dig out partial weak soil in the soft soil foundation and form the slot, pour box basis in the slot, in order to replace the weak soil of being dug out, because box basis is hollow structure, make when the volume is the same, box basis's weight will be less than the weight of the weak soil of being dug out, lay the road bed on box basis again, make box basis's weight, the weight of road bed and the weight sum that the road bed bore equals the weight of the weak soil of being dug out of slot part, make the soft soil foundation not increase extra weight, the stress that box basis bottom surface received at this moment equals with the same level of dead weight stress in the soft soil foundation, the stress condition of soft soil foundation does not change, the soft soil foundation can not take place to subside, and then the road bed can not produce vertical subsidence yet, in addition, box basis also can regard as the utility tunnel use of underground, the system is used for construction and management of pipelines for drainage, electric power, communication and the like, so as to fully utilize underground space.
Drawings
FIG. 1 is a schematic structural view of a conventional soft soil foundation;
fig. 2 is a schematic structural view of a soft soil foundation after a roadbed is paved in the prior art;
fig. 3 is a schematic view of the soft soil foundation structure of the present invention;
FIG. 4 is a schematic view of the box-type foundation of the present invention along the length and width direction;
fig. 5 is a schematic view of the cross section of the box foundation and the roadbed of the present invention.
The figures are numbered: 1. soft soil foundation; 2. a box type foundation; 3. a roadbed; 4. a partition plate; p0The self-weight stress of the soft soil foundation; p is the stress on the bottom surface of the box-type foundation; l is the length of the box-type foundation; w is the width of the box foundation; h2The height of the box foundation; p1Base stress induced for vehicle loading; p2Base stress caused by roadbed loading; p3Base stress induced for box foundation loading; h1Filling up the roadbed; 101. soft soil foundation; 102. soft soil foundation surface; 103. the self-weight stress distribution curve of the soft soil; 201. soft soil foundation; 202. soft soil foundation surface; 203. a roadbed; 204. dead weight of soft soilA force distribution curve; 205. additional stress curves are applied.
Detailed Description
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown.
Please refer to fig. 3, the utility model provides a soft soil foundation structure, including soft soil foundation 1, box basis 2 and road bed 3, soft soil foundation 1 is equipped with the slot, and box basis 2 is located the ditch inslot, and box basis 2 is hollow structure, and road bed 3 covers in box basis 2's upper surface, and the weight sum that road bed 3's weight, box basis 2's weight and road bed born equals with the soft soil weight of the slot part of soft soil foundation 1. Digging partial soft soil in the soft soil foundation 1 to form a groove, pouring a box type foundation 2 in the groove to replace the dug soft soil, wherein the box type foundation 2 is of a hollow structure, so that when the volume is the same, the weight of the box type foundation 2 is less than that of the dug soft soil, paving a roadbed 3 on the box type foundation 2, and the sum of the weight of the box type foundation 2, the weight of the roadbed 3 and the weight born by the roadbed is equal to the weight of the dug soft soil in the groove part, so that the soft soil foundation 1 is not added with extra weight, and the stress P born by the bottom surface of the box type foundation at the moment is equal to the self-weight stress P at the same level in the soft soil foundation 10Equal, soft soil foundation 1's stress state does not change, and soft soil foundation 1 can not take place to subside, and then road bed 3 can not produce vertical settlement yet, and in addition, box basis 2 also can regard as the utility tunnel use of underground for the construction and the management of pipelines such as drainage, electric power, communication, in order to make full use of underground space.
Referring to fig. 3-5, the soft soil foundation structure further includes a partition plate 4, the partition plate 4 is disposed in the box-type foundation 2, and the partition plate 4 divides the box-type foundation 2 into a plurality of partitioned cavities. The arrangement of the partition plates 4 can enhance the overall structural strength of the box type foundation 2, so that the overall service life of the soft foundation structure is ensured.
The partition boards 4 comprise a plurality of longitudinal partition boards 4 which are parallel to each other and a plurality of transverse partition boards 4 which are parallel to each other, and the longitudinal partition boards 4 are vertical to the transverse partition boards 4; the longitudinal partitions 4 are equally spaced apart from the transverse partitions 4. But not limited to, only longitudinal partition plates 4 can be arranged in the box-type foundation 2, and transverse partition plates 4 are not arranged, and the structural strength of the box-type foundation 2 mainly depends on the vertical structural strength, so that the overall weight of the box-type foundation 2 can be reduced by only arranging the longitudinal partition plates 4 on the premise of ensuring the structural strength of the box-type foundation 2. The arrangement of the partition board 4 can be set according to specific use conditions.
The upper surface of the box type foundation 2 is 0.30-0.70m higher than the surface layer of the soft soil foundation 1, so that the excavation depth of the soft soil foundation 1 can be reduced, the actual filling height of the roadbed 3 can be reduced and the construction workload is greatly reduced on the premise of ensuring the stable structure of the box type foundation 2.
The box-type foundation 2 is a reinforced concrete box. The reinforced concrete box has high strength, very high compressive strength, bending tensile strength and abrasion resistance, can be used for heavy-load traffic, and has good stability, the overall strength is gradually improved along with the prolonging of time, the aging phenomenon can not occur, the reinforced concrete box is durable and has long service life.
The cross section of the roadbed 3 is trapezoidal; the cross section of the box type foundation 2 is rectangular, the design is reasonable, and the structural strength has stability. The slope rate of the side slope of the roadbed 3 is 1:1.5, so that the roadbed 3 can be well protected and supported.
The material of the roadbed 3 is lime soil, and compared with the roadbed filling material of soil-rock mixture, the roadbed 3 made of lime soil has high strength and good integrity, can greatly prolong the service life of the pavement, and has low manufacturing cost and good economical efficiency.
The utility model discloses soft soil foundation structure's construction method for foretell soft soil foundation structure's construction, the step is as follows:
the method comprises the following steps: construction preparation, namely designing a structure of a box type foundation 2 according to the soft soil foundation 1;
step two: digging part of soft soil in the soft soil foundation 1 to form a groove for pouring the box type foundation 2;
step three: pouring the box type foundation 2 in the groove to enable the outer wall of the box type foundation 2 to be attached to the soft soil foundation 1;
step four: preparing roadbed 3 filler, paving the roadbed 3 filler on the upper surface of the box type foundation 2 to form the roadbed 3, and compacting the roadbed 3.
Digging partial soft soil in a soft soil foundation 1 to form a groove, pouring a box type foundation 2 in the groove to replace the dug soft soil, wherein the box type foundation 2 is of a hollow structure, so that when the volume is the same, the weight of the box type foundation 2 is less than the weight of the dug soft soil, then paving a roadbed 3 on the box type foundation 2, the sum of the weight of the box type foundation 2, the weight of the roadbed 3 and the weight borne by the roadbed is equal to the weight of the dug soft soil in the groove part, so that the soft soil foundation 1 is not added with extra weight, the stress P borne by the bottom surface of the box type foundation is equal to the self-weight stress P0 at the same level in the soft soil foundation 1, the stress state of the soft soil foundation 1 is not changed, the soft soil foundation 1 can not be settled, further the roadbed 3 can not be settled vertically, in addition, the box type foundation 2 can also be used as an underground comprehensive pipe gallery, the system is used for construction and management of pipelines for drainage, electric power, communication and the like, so as to fully utilize underground space.
And the roadbed 3 filler in the fourth step is lime soil prepared by mixing lime and the soft soil dug in the second step. The dug soft soil is used as a raw material, so that the aim of comprehensively utilizing waste soil can be fulfilled, the environment is protected, and the construction cost is reduced; meanwhile, the mountain excavation caused by the purchase of the roadbed 3 filling can be avoided, and mineral resources are saved.
In one embodiment, the box foundation is constructed as follows:
and at present, a certain section of a certain expressway is selected for carrying out soft soil foundation structure design. The design is suitable for a bidirectional six-lane highway, the design speed is 100km/h, the roadbed width is 33.5m, the roadbed 3 filling height of the highway section is different from 3.96m to 4.31m, the average filling height is about 4.0m, and the side slopes on two sides of the roadbed 3 are all 1:1.5, 2 percent of 3 transverse slopes of the roadbed and the designed load of the highway is grade I.
(1) Detecting engineering geology
The foundation of this section is located the area of the plain of area of sea area, and the relief is wide and flat. Drilling to reveal clay on the surface layer under the foundation, wherein the clay is gray yellow and plastic and has the thickness of 0-1.6 m; the lower layer is silt, gray, fluid plastic and high in compressibility and has the thickness of about 14 m; the specific parameters of the underburden sludge, gravel and clay are shown in the following table 1:
TABLE 1 geological section of foundation and each layer of geological foundation parameters
Figure BDA0002745174120000061
(2) Box type foundation plane dimension planning
Referring to fig. 4 and 5, the box-type foundation 2 is 0.50m thick, and the partition plates 4 are 0.30m thick. The length L of the box-type foundation 2 is 100m, the width W is 44m, and the height H2
(3) Substrate stress calculation
3.1 base stress P caused by vehicle load1
According to the general design specifications of highway bridges and culverts, the design is bidirectional six lanes, the width of a roadbed is 33.5m, the transverse arrangement of vehicle loads is considered according to eight heavy vehicles, and the stress on a base 2 of the box type foundation under the action of the vehicle loads is as follows:
P1=∑G/A=8×550/[(33.5+3×(H1-0.5))×(13+2×(H1-0.5)×TAN(30°))]=5.87KN/m2
3.2 base stress P caused by roadbed loading2
The top width of the roadbed 3 is 33.5m, and the slope rate of the side slope of the roadbed 3 is 1:1.5 roadbed 3 high H14.0m, the top plate of the box foundation 2 extends into the bottom of the roadbed 3 by 0.50m, and the width of the roadbed bottom is 3 (H)1-0.5). The roadbed filling adopts lime soil, and the volume weight of the lime soil is 18KN/m3
P2=∑G/A=[(33.5+33.5+3(H1-0.5))×(H1-0.5)/2]×γ/[33.5+3×(H1-0.5)]=55.48KN/m2
3.3 base stress P caused by Box Foundation load3
In order to reduce the excavation depth of the foundation, the height of the box foundation 2 exposed out of the soft soil foundation 1 is about 0.50m, so that the actual filling height of the roadbed 3 is reduced by 0.50 m. The transverse width of the box-type foundation 2 is 33.5+3 (H)1-0.5) m, calculated as 5m in the longitudinal direction of the substrate stress. The thickness of the box-type foundation 2 is 0.50m, the side of the box-type foundation 2 where the upper surface is located is a top plate, and the bottom surface of the box-type foundation 2 is locatedOne side of the box-type foundation is a bottom plate, the partition plate in the box-type foundation 2 is 0.30m, and the height of the box-type foundation 2 is H2The box body is cast by C30 reinforced concrete with the concrete density of 25KN/m3
∑G=GTop board+GBase plate+GTransverse partition+GLongitudinal partition
P3=∑G/A=[(33.5+3(H1-0.5)-2×0.5)+(5-2×0.3)×6]×0.3×(H2-2×0.5)×γ/[(33.5+3×(H1-0.5))×5]+2×0.5×γ=2.37H2+22.63
3.4 Soft soil foundation deadweight stress P0
The soft soil foundation of the box type foundation 2 has two layers, the first layer soil is clay, the thickness of the soil layer is 1.6m, and the natural wet density is 19.7KN/m3The second layer is sludge, the thickness of the soil layer is 13.8m, and the natural wet density is 16.5KN/m3
P0=γh=1.6×19.7+(H2-0.5-1.6)×16.5=16.5H2-3.13
(4) Box type foundation height calculation
In order to prevent the base of the box-type foundation 2 from generating additional stress, namely the self-weight stress of the soft soil foundation 1 is equal to the base stress generated by the upper load, wherein the stress P ═ P received by the bottom surface of the box-type foundation1+P2+P3I.e. by
P0=P1+P2+P3
16.5H2-3.13=5.87+55.48+2.37H2+22.63
H2=6.1m
(5) Box type foundation height corresponding to different roadbed filling height
Through calculation and analysis, when the base of the box type foundation 2 does not generate additional stress, the influence of the width of the roadbed 3 and the natural wet density of the sludge on the burial depth of the box type foundation 2 is small, the burial depth of the box type foundation 2 is mainly influenced by the filling height of the roadbed 3, and a corresponding parameter table of the box type foundation 2 is determined according to the calculation of the filling heights of different roadbeds 3 by the method, and is detailed in a table 2.
TABLE 2 relationship of subgrade fill height to box foundation
Figure BDA0002745174120000081
The above is only the preferred embodiment of the present invention, and not the patent protection scope of the present invention is limited thereby, all the equivalent structure changes made by the contents of the specification and the drawings of the present invention can be directly or indirectly applied to other related technical fields, and all the same principles are included in the protection scope of the present invention.

Claims (6)

1. The utility model provides a soft soil foundation structure, its characterized in that, includes soft soil foundation, box basis and road bed, the soft soil foundation is equipped with the slot, box basis is located the ditch inslot, box basis is hollow structure, the road bed cover in box basis's upper surface, the weight of road bed the weight that the road bed bore and box basis's weight sum with the soft soil weight that the slot part of soft soil foundation was dug out equals.
2. A soft soil foundation structure as claimed in claim 1, further comprising a partition plate disposed within the box-type foundation to enhance the structural strength of the box-type foundation.
3. A soft soil foundation structure as claimed in claim 2, wherein said partitions include a plurality of longitudinal partitions parallel to each other and a plurality of transverse partitions parallel to each other, said longitudinal partitions being perpendicular to said transverse partitions; the longitudinal clapboards and the transverse clapboards are arranged at equal intervals.
4. A soft soil foundation structure as claimed in claim 1, wherein the upper surface of said box foundation is 0.30 to 0.70m higher than the surface layer of said soft soil foundation.
5. A soft soil foundation structure as claimed in claim 1, wherein the box foundation is a reinforced concrete box.
6. A soft soil foundation structure as claimed in claim 1, wherein the cross section of the subgrade is trapezoidal, and the slope rate of the subgrade is 1: 1.5; the cross section of the box-type foundation is rectangular.
CN202022424307.8U 2020-10-27 2020-10-27 Soft soil foundation structure Active CN213804677U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202022424307.8U CN213804677U (en) 2020-10-27 2020-10-27 Soft soil foundation structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202022424307.8U CN213804677U (en) 2020-10-27 2020-10-27 Soft soil foundation structure

Publications (1)

Publication Number Publication Date
CN213804677U true CN213804677U (en) 2021-07-27

Family

ID=76962127

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202022424307.8U Active CN213804677U (en) 2020-10-27 2020-10-27 Soft soil foundation structure

Country Status (1)

Country Link
CN (1) CN213804677U (en)

Similar Documents

Publication Publication Date Title
CN107419630B (en) Soft soil foundation high-filling embankment capable of effectively controlling post-construction settlement and construction method
CN101250868B (en) Precipitation prepressing association motive power induration deep densification method
CN206902488U (en) A kind of soft soil foundation high-filled embankment of effectively control settlement after construction
CN101967786B (en) Airfield pavement structure with box-type shock-isolation foundation
CN210766223U (en) Roadbed structure capable of preventing settlement during drainage
CN109811748B (en) Freeway roadbed processing method in frozen soil area
CN104695419A (en) Soft soil roadbed construction method
CN102839683B (en) Granular pile-permeable concrete stake dual compound foundation and processing method
CN106836034B (en) High-fill cover plate culvert flexible load shedding system and construction method
CN213804676U (en) Soft soil foundation structure
CN112195701A (en) Soft soil foundation structure and construction method thereof
CN102296591A (en) Rapid drainage solidifying treatment method of soft soil foundation
CN102493485A (en) Method for building slope protection retaining wall during filling
CN213804677U (en) Soft soil foundation structure
CN203795260U (en) New roadbed and old roadbed combined road structure
JPH02504050A (en) Method for forming road and roadbed structures
CN1421575A (en) Light filled structure and its construction process
CN115652717A (en) High-fill roadbed construction method
KR20140114711A (en) Improvement Method for Base Ground of Pavement Block using Light-Weighted Foam Soil
CN202787211U (en) Low-strength rigid pile-permeable concrete pile novel dual compound foundation
RU2516603C1 (en) Road structure
KR100857922B1 (en) A sand mat execution method according to the cause that can make sand reduction through unnecessary section reduction for impeachment
CN113279290B (en) Construction method of railway waterproof roadbed structure in coastal high-water-level area
CN206127852U (en) Dark bridge of filling out bed course disconnect -type foundation structure is traded in adoption
CN1206423C (en) Constructing method for treating soft foundation of highway by cement, flyash and macadam

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant