The advantages of the application of foam light soil for road expansion and expansion project are mainly reflected in the following aspects:
The expansion of subgrade can be vertically filled to save land resources and avoid or reduce the demolition of buildings.
2. The expansion of the embankment of soft foundation can greatly reduce the load, which can save the soft foundation of the expansion roadbed or reduce the soft base processing strength; It also effectively reduces the difference settlement of new old roadbed and the additional settlement of nearby buildings.
3. With the construction of the piping pump, the construction takes up little space, which does not affect the existing traffic, and maintains the existing road facilities (anti-collision bars, gutters, etc.).
4. The widening of the steep section of the mountain can avoid the stability problem caused by high filling and excavation, and can maintain the natural mountain form and protect the natural environment.
5. Convenient construction and short construction period.
Second, the bubble of lightweight soil used for soft foundation abutment back filling the abutment soft ground road station back in filled bubble light earth used in soft ground section of the abutment back in filling machine, the use of lightweight, independence after curing, can be to make the following optimization routine method:
1. Optimize the double-row pile bridge platform for single row piles;
2. Significantly reduce the soft base processing strength. After optimization, reducing settlement and uneven settlement, eliminate back the post-construction settlement of embankment filling itself, to avoid car bump and greatly reduce maintenance costs work background back and so on technical and economic advantages.
3. The foam light soil is used for the old road bridge jumping car to control the conventional road and pavement construction method to add new pavement to the original road surface to reduce the slope difference caused by subsidence. Due to the increased load, total settlement after a further increase of maintenance, is bound to in the subsequent need to return to the same in a certain time and pavement maintenance, will cause the after service and the vicious circle of post-construction settlement. Bubble of lightweight soil replacement method for the first time after maintenance are required for the original roadbed fill foam light soil in filling, the foundation soil in the over-consolidated condition, as a result, the subsequent post-construction settlement radically eliminate, need not again extensions in pavement maintenance, vehicle dumpping problem can be solved once and for all.
4. The foam light soil is used for the steep section of the mountainous area. When the highway route passes through the steep section of the mountainous area, the foam light geotechnical method has the following advantages:
1. Reduce load, reduce the sliding moment of roadbed itself and improve the anti-sliding stability of roadbed; Avoid the high difficulty and high cost of roadbed anti-slip design and construction.
2. Avoid the stability problems caused by high filling and the disadvantages of large amount of land resources.
3. Avoid the cost of high slope support and damage to the environment caused by high excavation.
Five, the bubble of lightweight soil used for Bridges across different abutment back filling machine to reduce the bridge, when crossing the road flyover is higher, the conventional method to solve the problem of front abutment cone put slope length, number and length of bridge spans normally with two front cone slope foot from net control basis for design, the result is a bridge across the road by presidents often greater than the required width, was 1 span bridge can solve 2 ~ 3 across the cross road problems needed to solve, such as using thin wall type abutment, due to their high after filling, earth pressure is big, the abutment quality risks; In order to resist the soil pressure, the pile foundation and the cost of the platform will be greatly improved. Using foam light soil filling the abutment back, after curing little lateral pressure on the structure and vertical filling, can solve the problem of earth pressure and the front cone slope slope and abutment optimization for simple single pile column type abutment and reduce for cone slope slope increased across the bridge, greatly reduce the project cost.
Six, foam light soil for underground structure load reducing the underground tunnel engineering, the tunnel structure design requirements for the covering load must be within the scope of the structure can withstand, as the actual soil load exceeds the capability of the structure, you must to relieving the overlying soil. If foam light soil is used to replace the design, it is easy and convenient to reinforce the underground tunnel structure, and it has obvious technical and economic advantages.
Seven, foam light used in foundation pit and underground pipeline backfill soil in civil engineering, for some narrow underground space, such as the construction of foundation pit and underground pipeline engineering surrounding space, due to mechanical and unable to work or work space is too narrow to backfill is close-grained, make the construction of a big difficulty. Using foam can be made of the hose pump light soil, casting ShiGongDian accounts for a tiny space, casting has high liquidity, after the casting can be cured and the advantages of without mechanical compaction or vibrating backfill these special hole, can achieve the construction is simple and the effect of density of backfill, to solve the problem of void backfill technology provides a brand-new. Especially the foundation ditch backfilling, can avoid traditional method of backfilling caused by imperfect hazard: in the wind load and earthquake load under the action of horizontal force, such as building may slip due to the lack of horizontal resistance level, lead to the unstability of the building.
Eight, foam light soil in the tunnel construction, tunnel import and export of filling the import and export of the tunnel location due to natural mountain shape is irregular, the larger bias existed during excavation, the mountain collapse easily. Therefore, the conventional method usually need to import and export of location and protection of slope excavation of tunnel engineering, this not only increased the difficulty of excavation, more important is destroyed the natural mountain form, interfere with the balance of natural geological geographical environment. If a certain form of foam light soil is preset in the position of import and export, the defects of conventional methods can be avoided. The advantages of foam light soil filling are: to relieve the confining pressure of the tunnel and to avoid the collapse of the mountain. Avoid the destruction of natural mountain form, maintain the natural geological environment balance as far as possible, the environmental protection advantage is obvious. The light soil fill can be used as an auxiliary structure for tunnel import and export. The construction is convenient and efficient and safe.
Nine, bubble of lightweight soil for engineering repair and emergency rescue Because the foam light soil has light weight, good construction and construction advantages of simple equipment, short construction period, is an ideal material to engineering emergency repair, especially for those who need to be filling, filling to restore emergency repair project, the advantage of the bubble of lightweight soil is more obvious.
10. Foam light soil for special section filling
1. The new expressway route will often cross the karst zone or the goaf zone in the light and soft soil karst area. To build embankments in these areas, especially the embankments, measures must be taken to avoid the collapse of karst or goaf. These measures include grouting, dynamic ramming, etc. But as a result of karst area, the complexity of the rules of distribution of underground cavity of mined-out area, the conventional method of processing or costly, or could not process completely, even with a bridge across the section, because of the complexity of the underground karst area, the goaf empty distribution, the quality of pile foundation construction is still there is a huge risk. While using foam light dirt road embankment, due to the load can be reduced to only about a third of the conventional embankment, the karst area and the bearing capacity of mined-out area can be greatly reduced, its corresponding treatment measures can greatly simplify or do not, and technical quality more secure, compared with the conventional embankment filling, provides a new technical means, so to speak.
2. Cold foam lightweight soil road embankment cold road, the prevalent form of permafrost roadbed and road surface pumping frost heave, the abutment damage caused by Taiwan back subgrade frost heaving damage, using foam light soil for subgrade filling, cold and use of lightweight soil contains a lot of bubbles, has the thermal insulation performance, can effectively keep the subgrade soil temperature difference within the scope of the permit, avoid seasonal changes alternately freezing and thawing of permafrost thawing settlement, frost heaving were formed by the road diseases.
