The method of composite earthwork synthetic materials reinforcement cushion soft soil foundation
The present invention relates to a kind of method of composite earthwork synthetic materials reinforcement cushion soft soil foundation.Be applicable to geotechnical engineering Soft Ground field.
Along with economic development and population increase, land resources contradiction in short supply is more and more outstanding, and reclaiming land around sea has all been carried out in coastal many areas.Facts have proved the use Tidal Flat Resources held water, scientific and reasonable carries out reclaiming land around sea planning and designing, not only can expand urban land, can also build new beautiful view, beautifying urban environment.Along with urbanization constantly advances, the newly-built development zone of reclaiming land around sea, Xincheng District and port district etc. are often taked in coastal area, and these all need the land to enclosing sea formation to carry out large area backfill and basement process.Backfill adopts layering hydraulic reclamation or throwing mode, and backfilling material has sand, earth, rubble or pool slag etc.Method for processing foundation is a lot, as consolidation (piling prepressing, vacuum preloading), compound foundation method (cement mixing pile, broken stone pile), foundation pile method (preformed pile, castinplace pile), but various adaptation of methods scope and economy different, need suit measures to local conditions.Consolidation, the consolidation of " piling prepressing+vacuum preloading ", the cement mixing pile composite foundation method of the consolidation that large-area soft ground process often adopts " plastic draining board or sand wick+sand or hardcore bed+preloading or surcharge preloading ", " plastic draining board or sand wick+sand or hardcore bed+vacuum preloading ", also to have on natural ground a directly backfill and do not process soft foundation.
Being no matter adopt consolidation or compound foundation method, is all to improve load-carrying capacity of soft soil foundation, eliminates in advance or reduces soft soil base sedimentation and differential settlement, but needs that the duration is longer, disposal cost is higher.And the general weak soil in coastal area deep (>=30m), cannot depth bounds process entirely, so cause settlement after construction or differential settlement larger, be difficult to meet relevant regulatory requirements, its reason is that soft foundation is under imposed load effect, water in weak soil is constantly discharged by plastic draining board, sand wick, bed course and backfill layer, and soft foundation constantly produces consolidation settlement.If the water in soft foundation can be stoped to discharge, make soft foundation not consolidation, consolidation settlement does not occur, then settlement after construction will not occur or greatly reduce, to meet relevant regulatory requirements.
Summary of the invention
The technical problem to be solved in the present invention is: for above-mentioned Problems existing, the method of the composite earthwork synthetic materials reinforcement cushion soft soil foundation of shorter, less engineering investment of a kind of duration is provided, to seal water in soft foundation, water is avoided to discharge from foundation surface, bed course or backfill layer, improve Soft Base Stabilization, reduce settlement after construction.
The technical solution adopted in the present invention is: a kind of method of composite earthwork synthetic materials reinforcement cushion soft soil foundation, is characterized in that comprising the following steps:
1, dig in composite earthwork synthetic materials reinforcement cushion treatment region surrounding the sealing ditch that the degree of depth and width are 1-2m;
2, first lay one deck geomembrane on soft foundation surface, geomembrane four limit is embedded in sealing ditch;
3, on geomembrane, lay the argillic horizon of a layer thickness 200-400mm, and it is closely knit to seal trench backfill with clay;
4, on argillic horizon, lay the non-woven fabrics of one deck 200g ~ 400g;
5, on non-woven fabrics, lay the high-strength geosynthetics of one deck;
6, on high-strength geosynthetics, lay the alternating layers of sand or rubble and high-strength geosynthetics, form reinforcement cushion, each alternating layers thickness 200-400mm, the gross thickness of reinforcement cushion is not less than 1m;
7, reinforcement cushion above using ballast aggregate as backfill layer until target elevation.
Described high-strength geosynthetics adopts inflection parcel in both side ends.
Described high-strength geosynthetics is geo-grid, Soil test, geotechnical grid or woven type geotextile.
On described backfill layer, ditch buried underground by reserved pipeline, and this is buried underground in ditch and installs pipeline.
Cement paste is poured in reinforcement cushion.
The invention has the beneficial effects as follows: soft-soil foundation treatment method of the present invention has easy construction, the duration is short, cost is low, bearing capacity is high, settlement after construction is little and the advantage such as energy-conserving and environment-protective.After the inventive method process, effectively can pin the moisture content in soft foundation, avoid water to discharge from foundation surface, bed course or backfill layer, improve Soft Base Stabilization, reduce settlement after construction.Reinforcement cushion and backfill layer are formed huge " aircraft carrier " that be docked on soft foundation, then build road and building etc. on " aircraft carrier ", safe, economical, reliable.
Accompanying drawing explanation
Fig. 1 is structural representation of the present invention.
Fig. 2 is A portion enlarged diagram in Fig. 1.
Detailed description of the invention
As shown in Figure 1 and Figure 2, the present embodiment is a kind of method adopting composite earthwork synthetic materials reinforcement cushion soft soil foundation, the specifically processing method of the soft foundation of a road.Composite earthwork synthetic materials reinforcement cushion is made up of geomembrane 1, argillic horizon 9, high-strength geosynthetics 7, non-woven fabrics 8, sand or rubble 10 etc., is formed and can play a part to stop water in soft foundation to discharge the bed course that can play again reinforced action.
Geomembrane 1 is laid immediately on soft foundation surface and geomembrane 1 surrounding is embedded in the sealing ditch 2 of foundation surface, and sealing ditch 2 degree of depth is not less than 1m.Geomembrane 1 is laid the argillic horizon 9 that a layer thickness is not less than 200mm, argillic horizon 9 is laid the above non-woven fabrics 8 of one deck 200g, non-woven fabrics is laid the high-strength geosynthetics 7 of one deck, this example adopts geo-grid.Geomembrane 1, argillic horizon 9 form the water-stopping structure with high strength, the argillic horizon 9 that geo-grid is laid and the above non-woven fabrics 8 of one deck 200g below jointly with non-woven fabrics 8, can be used for protection geomembrane 1 and are not punctured.The alternating layers of sand or rubble 10 and high-strength geosynthetics 7 above geo-grid, these alternating layers can have multilayer and form reinforcement cushion 6, cement paste can be poured in its medium sand or rubble 10, to improve rigidity and the intensity of reinforcement cushion 6, improve Soft Base Stabilization (this layer also can directly substitute with plain concrete), the thickness 200mm ~ 400mm of these alternating layers every layer.Reinforcement cushion 6 gross thickness is determined according to correlation computations theory and principle, is generally not less than 1m thickness.Using ballast aggregate as backfill layer 5 until road surface elevation on reinforcement cushion 6.Backfill layer 5 is reserved or excavates pipeline and bury ditch 4 underground, this is buried underground in ditch and installs pipeline 3.
The present invention also can directly use geomembrane+geo-grid composite material to replace geomembrane 1, argillic horizon 9 and geo-grid to be laid on soft foundation surface.The high-strength geosynthetics 7 that this example adopts adopts inflection parcel, to give full play to its reinforced action in its both side ends.
The concrete construction method of the present embodiment is as follows:
1, dig in composite earthwork synthetic materials reinforcement cushion treatment region surrounding the sealing ditch 2 that the degree of depth and width are 1-2m;
2, first lay one deck geomembrane 1 on soft foundation surface, geomembrane four limit is embedded in sealing ditch 2;
3, on geomembrane 1, one deck argillic horizon 9 is laid;
4, on argillic horizon 9, lay the non-woven fabrics 8 of more than one deck 200g;
5, on non-woven fabrics 8, lay the high-strength geosynthetics 7 of one deck, high-strength geosynthetics 7 both side ends adopts inflection parcel;
6, on high-strength geosynthetics 7, sand or rubble 10 and high-strength geosynthetics 7 alternating layers are laid in interval, and form reinforcement cushion 6, wherein high-strength geosynthetics 7 both side ends adopts inflection parcel, pours into cement paste in sand or macadam 10;
7, reinforcement cushion 6 above using ballast aggregate as backfill layer 5 until road surface elevation;
8, ditch 4 buried underground by reserved on backfill layer 5 or excavation pipeline, and this is buried underground in ditch and installs pipeline 3.