CN203212962U

CN203212962U - Expressway cut and fill subgrade on segment with less ice or more ice

Info

Publication number: CN203212962U
Application number: CN2013201993173U
Authority: CN
Inventors: 刘戈; 章金钊; 樊凯; 李金平; 符进; 朱东鹏; 袁堃
Original assignee: CCCC First Highway Consultants Co Ltd
Current assignee: CCCC First Highway Consultants Co Ltd
Priority date: 2013-04-19
Filing date: 2013-04-19
Publication date: 2013-09-25
Anticipated expiration: 2023-04-19

Abstract

The utility model relates to an expressway cut and fill subgrade on a segment with less ice or more ice. Cut sections of cut and fill transition sections can bring in heat in the cut construction process, thus affecting permafrost and destabilizing subgrades. The cut and fill subgrade is characterized in that a replacing gravel layer is arranged below a pavement structure layer of a cut section and is provided with a side slope and a cross slope on the bottom surface; a whole-section waterproof geotextile is arranged below the replacing gravel layer; steep slope steps are arranged in a height interval from a position 80cm below a pavement structure layer of a fill section to the intersection of a steep slope and a ground line; clean gravels or rock ballast fillers are arranged on the steep slope steps layer by layer; and a plurality of layers of geogrids are paved in the clean gravels or rock ballast fillers from top to bottom. The subgrade is a change of traditional cut and fill subgrade engineering measures, is low in construction cost, has long service life, strong bearing capacity and good water resistance, and effectively solves the subgrade defect problems of permafrost regions with less ice or more ice.

Description

A kind of few highway section speedway cut-fill subgrades of icing, ice more

Technical field

The utility model relates to a kind of roadbed, is specifically related to a kind of few ice, ices highway section speedway cut-fill subgrades more.

Background technology

Ever-frozen ground district roadbed design should adopt the principle of " rather do not fill out and dig ", as far as possible based on filled-up ground, and the design principles of adopt protection frozen soil, initiatively lowering the temperature and allowing frozen soil to melt.Several important highways that enter into Tibet such as existing Qinghai-Tibet Highway, blue or green Kanggong road, after all previous maintenance, reconstruction, reconstruction, at ever-frozen ground, particularly high ice content ever-frozen ground district all is to pass through with embankment basically.But, along with further going deep into of development of the West Regions, the further upgrading of country's road network, perfect, the area, Qinghai-Tibet Platean is because of demands such as national defense construction, economic development and tourism developments, need transform, upgrade original low-grade highway, in the build process of new highway, the excavation roadbed will inevitably occur, and between excavation roadbed and filled-up ground, will exist one to fill out longitudinally and dig changeover portion.

Fill out and dig changeover portion and have following problem, at first fill out the heat that the excavation section of digging changeover portion is brought in heat that the excavation construction process is brought into and excavation face put procedure, all can impact ever-frozen ground under the roadbed; Secondly also may cause rainwater to enter the soil body under the roadbed in the construction, water and heat enter lower floor's soil body, will cause the particularly acute variation of high ice content ever-frozen ground of ever-frozen ground, cause the subgrade soil temperature to raise, the upper limit descends, and influences subgrade stability.At last, the cross transition of embankment section and excavation section and the control of filler also affect resistance to overturning and the durability during the cut-fill subgrades operation, therefore, for ever-frozen ground district cut-fill subgrades, also do not have corresponding treatment measures.

Summary of the invention

The purpose of this utility model provides a kind of few ice, ices highway section speedway cut-fill subgrades more, can effectively avoid few ice, ice whole unstability that ever-frozen ground district abrupt slope roadbed may occur and along the slope or the soft layer band destruction of sliding more.

The technological means that the utility model adopts is:

A kind of few ice, ice highway section speedway cut-fill subgrades more, it is characterized in that:

The horizontal wall inscription that the back-up sand gravel bed arranges side slope and bottom surface is changed for changing the back-up sand gravel bed in the road surface structare layer below of excavation section; Change back-up sand gravel bed below and be full section water proof geotextiles;

The road surface structare layer of embankment section below 80cm arranges the abrupt slope step to abrupt slope and height interval, above-ground route intersection, successively be provided with clean gravel on the step of abrupt slope or rock ballast fills, and lays some layers of geo-grid from top to bottom during clean gravel or rock ballast fill.

The described thickness that changes the back-up sand gravel bed is 80cm, and its grade of side slope is 1:0.5, and the bottom surface horizontal wall inscription gradient is 2%.

Described geo-grid is provided with four layers, and orlop is arranged on abrupt slope roadbed embankment height 5m place, and each interlamellar spacing is 100cm.

The excavation step width of described abrupt slope step is 2m, to excavation face introversion 2%～4%.

Described road surface structare layer edge is provided with guardrail.

Described road surface structare layer goes up a slope and is provided with the dash sth. made by twisting.

The utlity model has following advantage:

The abrupt slope roadbed that the utility model is related is that construction cost is low to the change of traditional cut-fill subgrades engineering measure, long service life, and bearing capacity is strong, and good waterproof performance has solved few ice effectively, has iced the subgrade defect problem in ever-frozen ground district more.

Description of drawings

Fig. 1 is the utility model structure chart.

Among the figure, 1-abrupt slope step, the clean gravel of 2-or rock ballast fill, the 3-geo-grid, 4-waterproof geotextiles, 5-guardrail, 6-change the back-up sand gravel bed, the 7-road surface structare layer, the 8-dash is twisted with the fingers.

The specific embodiment

Below in conjunction with the specific embodiment the utility model is described in detail.

A kind of few highway section speedway cut-fill subgrades of icing, ice more described in the utility model, be applicable to few ice, ice the operating mode that the transition highway section of partly digging is partly filled out in the ever-frozen ground district more, its concrete structure is: road surface structare layer 7 belows of excavation section are for changing back-up sand gravel bed 6, change the horizontal wall inscription that back-up sand gravel bed 6 arranges side slope and bottom surface, the thickness that changes back-up sand gravel bed 6 is 80cm, its grade of side slope is 1:0.5, and the bottom surface horizontal wall inscription gradient is 2%.Changing back-up sand gravel bed 6 belows is full section water proof geotextiles 4.The road surface structare layer 7 below 80cm of embankment section arrange abrupt slope step 1 to abrupt slope and height interval, above-ground route intersection, the excavation step width of abrupt slope step 1 is 2m, to excavation face introversion 2%～4%.Successively be provided with clean gravel on the abrupt slope step 1 or rock ballast fills 2, clean gravel or rock ballast fill to be laid four layers of steel from top to bottom and moulds geo-grid 3 in 2, and orlop is arranged on abrupt slope roadbed embankment height 5m place, and each interlamellar spacing is 100cm.Road surface structare layer 7 edges are provided with guardrail 5, and road surface structare layer 7 goes up a slope and is provided with dash sth. made by twisting 8.

Concrete job practices is as described below:

Step 1: change the back-up sand gravel behind the 80cm that backbreaks under the excavation section road structure layer, grade of side slope excavates into 1:0.5 when changing the back-up sand gravel, cutting depth is 80cm under the road surface structare layer, the bottom surface becomes 2% horizontal wall inscription, its underpart arranges one deck water proof geotextiles, and the water proof geotextiles is backfilling into the following 80cm height layer of road surface structare layer holostrome and lays digging step.

Step 2: the following 80cm of embankment road section surface deck digs step compacting successively to side slope and height interval, above-ground route intersection, step excavates from the bottom, the excavation step width is 2.0m, to excavation face introversion 2%～4% horizontal wall inscription, fill out and dig the every 1m of intersection and carry out tamping one time, compacting width 8m, laterally uneven because of sedimentation to reduce roadbed, all fill with clean gravel or rock ballast after digging step.

Step 3: cut-fill subgrades is when embankment height〉5m or when being in steep bank, to lay four layers of steel and mould geo-grid in that excavation step rolling layers is continuous from top to bottom, spacing is 100cm.The above roadbed of water proof geotextiles all fills with gravel.

Excavate again when preliminary preparation is made adequate preparation to change and fill out operation, should in time construct behind the excavation, forbid airing, stop to excavate excavation hole, back ponding.

It is cited that content of the present utility model is not limited to embodiment, and the conversion of any equivalence that those of ordinary skills take technical solutions of the utility model by reading the utility model manual is claim of the present utility model and contains.

Claims

Few ice, ice highway section speedway cut-fill subgrades more, it is characterized in that:

The horizontal wall inscription that back-up sand gravel bed (6) arranges side slope and bottom surface is changed for changing back-up sand gravel bed (6) in the road surface structare layer of excavation section (7) below; Change back-up sand gravel bed (6) below and be full section water proof geotextiles (4);

The road surface structare layer of embankment section (7) below 80cm arranges abrupt slope step (1) to abrupt slope and height interval, above-ground route intersection, successively be provided with clean gravel on the abrupt slope step (1) or rock ballast fills (2), clean gravel or rock ballast fill and lay some layers of geo-grid (3) in (2) from top to bottom.
A kind of few ice according to claim 1, ice highway section speedway cut-fill subgrades more, it is characterized in that:

The described thickness that changes back-up sand gravel bed (6) is 80cm, and its grade of side slope is 1:0.5, and the bottom surface horizontal wall inscription gradient is 2%.
A kind of few ice according to claim 1 and 2, ice highway section speedway cut-fill subgrades more, it is characterized in that:

Described geo-grid (3) is provided with four layers, and orlop is arranged on abrupt slope roadbed embankment height 5m place, and each interlamellar spacing is 100cm.
A kind of few ice according to claim 3, ice highway section speedway cut-fill subgrades more, it is characterized in that:

The excavation step width of described abrupt slope step (1) is 2m, to excavation face introversion 2%～4%.
A kind of few ice according to claim 4, ice highway section speedway cut-fill subgrades more, it is characterized in that:

Described road surface structare layer (7) edge is provided with guardrail (5).
A kind of few ice according to claim 5, ice highway section speedway cut-fill subgrades more, it is characterized in that:

Described road surface structare layer (7) goes up a slope and is provided with dash sth. made by twisting (8).