Summary of the invention
Flexible retaining structure provided by the invention has following architectural feature: the bottom of retaining structure has permeable layer for the infiltration basal layer between retaining structure and excavation face, and this permeable layer is an one with the infiltration basal layer; Infiltration basal layer excavation down has sewer; Lay the muscle material in whole retaining structure, every layer muscle material all surpasses the width of retaining structure, and anti-package is to last layer, and is connected the earthen backfill compacting of being excavated of every layers of reinforcement material with the muscle material of last layer.
Excavation has catchwater on the side slope of retaining structure upper end, top domatic shop geomembrane water proof to the catchwater edge extent.
Best sloping top catchwater should be arranged on beyond the sloughing body, is not less than 5m apart from sloughing body edge.
Further, excavation has french drain below catchwater.
The job practices of flexible reinforcement retaining structure disclosed by the invention is:
(1) the clear square one-tenth flexible retaining wall of side slope is built work plane;
(2) foundation excavation and rolling carries out static pressure to the basis, compaction requirement 〉=80%;
(3) sewer excavation and waterproofing course are laid;
(4) build permeable layer and infiltration basal layer with rubble;
(5) lay the muscle material, after the anti-package length of reserving, launch, and its tensioning is fixed along cross-sectional direction;
(6) the paving and rolling of filler, degree of compaction need reach more than 80%.
(7) muscle material anti-package will also just be opened on the anti-package grid section edge side slope anti-package of reserving of fixing; The end of following layers of reinforcement material anti-package is connected with pitman with the appropriate location of upper strata grid; And filler paves and rolls same lower floor.
(8) repeat the height that above-mentioned (5) to (7) step to retaining structure reaches to be needed.
(9) at the top to the catchwater edge extent domatic shop geomembrane water proof, sloping top backfill non-expansibility clay;
(10) the sloping top of excavation catchwater.
Be used for (6) and the soil of (7) step backfill can be expansive soil.
Preferably cultivate the unexpansive soil of 30cm, and spread planting soil, green grass thereon on anti-package side slope surface.
Flexible retaining structure adopts the muscle material layering anchoring that paves, and unexpansive soil of backfill or expansive soil compacting form the flexible retaining wall of adequate thickness, and the draining that is aided with sealing, the wall back of the body and the substrate on top, slope is again handled and can be brought into play following effect:
(1) the muscle material and banket between the frictional force and the interlayer of snap-in force and grid connect, anti-package can provide enough shear strengths, makes reinforced earth body constitute the effect that an integral body is resisted side slope;
(2) flexible retaining wall allows slope soil to produce certain deformation can the dissipate most of stress and the expansion force of excavation slope, " defeating a force with a tenderness ";
(3) enough thickness of wall body can completely cut off and prevent the influence (greater than the effective mobile layer degree of depth) of weathering to sloping volume expansion soil, stop the crack to further develop and shallow top layer sloughing.
Adopt the muscle material to dispose the expansive soil cut slope, with respect to the rigidity retaining structure, one, cheap, low more than 25%; Its two, have environmental benefit, adopt geo-grid, help the greening of earthing up on domatic, and the other way of rigidity retaining structure needs be afforested selling at exorbitant prices.
Specific embodiment
One. material is prepared:
Be ready to required material before the slope construction in the requsst listed below:
1. geo-grid (muscle material): simple tension geo-grid TL-35, limit elongation are 10%;
2. geotechnological pitman: the wide 1.2m geotechnique pitman that Z-TEK company in Hubei produces;
3. sloping top geomembrane: dark polyvinyl chloride plastic film, tensile strength 〉=20Mpa, the elongation per unit length when breaking 〉=200%, serviceability temperature scope-15~60 (degree), frost resistance-25 (degree).Thickness 0.18~0.2mm;
4. sewer bottom of trench two cloth one film: ZFM250, product are that normal continent geosynthetics Co., Ltd produces; Or fabric heavy/film is heavy/fabric is heavy=200/80/200 (g), thickness 0.98mm, Xiang Tan, Hunan plastics plant.
Two, construction technology process
(1) side slope is square clearly: earlier the end, side slope slope is carried out just clearly, the end, slope,, clear side's horizontal width was a starting point from former design side slope toe, and end to side slope slump loose measure and sliding border clearly in the slump district.Calculate by design barricade width+0.5m (drainage blanket width behind the wall) slump is not regional, clear side's substrate should scrape out the inclined-plane that tilts in side slope, the inclined slope ratio is 4%, and the assigned address of roadbed 1 used in order to flexible retaining structure backfill near the expansive soil that digs out was put in.
(2) geo-grid flexible retaining wall foundation excavation and rolling: geo-grid 2 flexible retaining wall foundation excavations to former roadbed changed fill out the position, want all clear clean if loosening the soil appears in basic part, up to hard soil layer, adopt road roller that static pressure is carried out on the basis then, compaction requirement 〉=80%.In the foundation excavation process if cause the loosening slump of the top soil body in foundation ditch, must loosening the soil in the foundation ditch is clean clearly.
(3) 3 excavations of the sewer under roadbed and the geo-grid flexible retaining wall and waterproofing course are laid: according to design drawing, adopt artificial or excavator excavates vertical sewer, the sewer top is positioned at roadbed to be changed and fills out gravelly soil bottom, performs antiseepage work in sewer bottom and side laying " two cloth, one film ".
(4) under roadbed and the geo-grid flexible retaining wall sewer gutter 4 arrange and ditch in the filling of rubble: arrange vertical Φ 10cm PVC gutter with holes as the longitudinal drainage passage in the sewer bottom, and rubble filled in the ditch.During construction, require that bottom of trench is smooth to be provided with the bottom of trench longitudinal gradient by excavation middle part to both sides, guarantee that current are unimpeded, outlet is established a word wall delivery port with reference to sewer outlet form under the catchwater.
On sewer, lay infiltration basal layer 9
With reference to figure 2, top, slope catchwater 5 and its sewer 6 down adopt hand excavation's foundation ditch, press shop, design drawing position geomembrane, spread cast-in-place C15 at the bottom of the sewer, lay flexible porous tube 7 (pipe that the permeable geotextiles of steel loop outsourcing forms) and backfill rubble after concrete is fixed, cast-in-place C20 catchwater is built in backfill hillside, sewer top topsoil (red residual soil) compacting back.Slope top sewer and catchwater should be arranged on beyond the sloughing body, be not less than 5m apart from sloughing body edge, and sewer and the catchwater bottom of trench is smooth, smooth and easy, the ponding not of current in the ditch, the bottom of trench longitudinal gradient is not less than 0.5%, sewer rises, terminal is established two one word wall delivery ports, in time discharges underground water.
(5) unwrapping wire: before every layer of geo-grid 2 paves, measure unwrapping wire, and mark side slope line and geo-grid bound edge line with pulverized limestone according to design drawing.To guarantee the realization of the straight of side slope and design ratio of slope.
(6) staple, grid are opened the preparation of tool and pitman: purchase pitman in special-purpose producer; Become 50cm long φ 6 reinforcing bar severings, curve the U sprig; With φ 10 reinforcing bars self-control grid stretch-draw instrument, in order to the usefulness of fixing and tensioning geo-grid.
(7) geo-grid 2 cuttings: with bundled geo-grid 2 by flexible retaining wall that the design width+1.5m length is carried out cutting is standby.The length of every layer of geo-grid 2 cutting must be carried out according to specific design figure.Cutting length is the design width+1.5m anti-package length of flexible retaining wall, near the assigned address of the roadbed standby geo-grid that cuts is positioned over.
(8) grid overlap joint: in order to guarantee the globality of grid along road center line direction, need overlap joint between two width of cloth grids, lap width is 5cm; And fix at overlapping part with staple, after afterbody was fixing, the spacing of middle part staple was 1.5m.
(9) preparation of expansive soil filler: according to the principle of getting material nearby, the expansive soil (rock) that slope excavation comes out is stacked at assigned address, and with the bulldozer crawler belt big particle diameter mud stone is crushed, the lumpiness of strict control filler is not more than 10cm.
(10) filling of permeable layer 8: adopt the artificial or mechanical gravelly soil that excavates being filled between the side slope face of the wall back of the body and basis or the clear Fang Suocheng of sloping body to carry on the back permeable layer 8 to form wall by wide 50cm * high 25cm, also can adopt treat down that one deck geo-grid is laid before, with excavator or the artificial ditch that excavates dark 50cm in clear side's side slope one side, fill out crushed stone soil layer then and form wall back of the body permeable layer, notice that cutting depth should guarantee to join with the permeable crushed stone soil layer of following one deck.For preventing that slope underground water from infiltrating roadbed, at shop, the geo-grid bag gravelly soil side slope outside, flexible retaining wall bottom one deck two cloth one film.(see figure 1)
(11) paving of first floor geo-grid: the grill reinforce district may require the residue position also to carry out decking and rolling simultaneously by the corresponding filler of the direct backfill of design drawing greater than the paving width of design grid with the square clearly formed new side slope line in basis.Geo-grid is launched toward the roadbed side slope direction from bound edge line place along cross-sectional direction after reserving 1.5 meters anti-package length, and with the U sprig its tensioning is fixed.By that analogy, the grid of first order barricade is all carried out as stated above.The grid of second level barricade is pressed design drawing and is carried out.The residue position of the formed new side slope line in the clear side of the grill reinforce district of second level barricade and side slope is equally by the corresponding filler of requirement backfill of design drawing.
(12) by first floor filler on the design drawing: the expansion earth material (or gravelly soil) that will get ready with loader or excavator is placed in the zone that reaches need backfill behind on the geo-grid.
(13) the paving and rolling of filler: it is flat to adopt bulldozer that filler is pushed away, and rolls with baby roller after reaching the planarization requirement; Number of rolling should in time be adjusted according to actual conditions.Notice that construction machinery must not directly be walked on geo-grid.
(14) go up second layer filler: directly the soil layer of first floor compacting with the soil of charge make-up area or side slope above landslide soil as second layer filler, paving and leveling also rolls.
(15) unwrapping wire: the ratio of slope by design drawing is measured unwrapping wire.
(16) repair the slope: the two-layer soil after employing manually will be filled and roll is accomplished the slope ratio of 1:1.5.
(17) first floor geo-grid anti-package: will also just open on the anti-package grid section edge side slope anti-package of reserving of fixing.
(18) paving of second layer geo-grid: paving of second layer geo-grid carried out in the requirement by design drawing and (11) bar, grid is reserved the bound edge length of 1.5m, and off-the-shelf one section geo-grid is launched toward the roadbed side slope direction from bound edge line place along cross-sectional direction;
(19) grid connects and overlap joint: the end of lower floor's grid is connected (being advisable with its end after the grid tensioning of upper strata) with the appropriate location of upper strata grid with pitman near the bound edge line, in order to guarantee the globality of grid along road center line direction, need overlap joint (width of grid is 1.3m) between two width of cloth grids, lap width is 5cm;
(20) stretch-draw and fixing: bilevel geo-grid is connected with pitman, instrument with a band row hook is held grid, manually strain grid along vertical road center line direction and produce 1%~2% elongation rate, pitman must firmly be clamped by two-layer geo-grid up and down, and uses " U " sprig with grid fixedly on the soil layer immediately.For preventing grid, need add nail " U " sprig along the middle part of vertical road center line direction in lap-joint because of falling local products change shape or fold;
(21) repeat (11) to (20) step, up to the top of barricade.
(22) part that needs backfill to fill is pushed up on the slope: press design drawing and carry out.The soil layer compacting can be adopted machinery or baby roller.The side slope ratio of slope adopts 1:1.5.
(23) side slope binds: above backfill and the expansive soil slope top lay geomembrane, lay width (hole to bench edge distance is from the catchwater distance) and be not less than 5m, the top is handled and press the design drawing execution.Geo-grid flexible retaining wall top domatic shop geomembrane water proof to the catchwater edge extent, and spread the thick planting soil of 30cm thereon, green grass before the geomembrane of shop, repair domaticly, clogs the crack.
(24) protection of domatic anti-package grid: cultivate 30cm on anti-package side slope surface unexpansive native 10, and along with construction progress from bottom to top bankets and makes real, to prevent the influence of ultraviolet ray to the grid life-span.And spread planting soil, green grass thereon.
Three, quality requirement and detection
After the clear side of side slope finished, whether the measurement that should carry out an acceptance inspection immediately met design requirement with check ratio of slope and clear side's width.
Each fill stratum loose laying depth is not more than 30 centimetres.Adopt the random sampling pattern excavation to detect 4 points, require minimum and maximum thickness to be no more than 5 centimetres, do not reach requirement, need carry out grading operation again, until reaching requirement as testing result.
Appropriate filler compaction determines according to the field conduct situation analysis.