Application of Expressway Reconstruction and Widening Roadbed Geocell
Abstract: plastic geocells for sale is a new type of geosynthetic material with a three-dimensional structure. In rock engineering, it is combined with soil, sand, stone and other fillers to form cushions with different visual cohesion, different reinforced strength, and different depths. These cushions can be placed in the required position according to the requirements of the project, to reinforce the roadbed, slope protection, construction of retaining walls, etc., and to realize the ecological restoration function along the road to achieving the purpose of greening and beautifying the environment.
Keywords: expressway; reconstruction and expansion of widened roadbed; plastic geocells factory price; application
1. Introduction
The plastic geocells manufacturers are made of high-strength polyethylene sheets and joined by ultrasonic welding. The three-dimensional grid structure that is honeycombed after the expansion is a special geosynthetic material. Its biggest feature is that it can complete a variety of difficult problems that are difficult to handle in conventional methods in rock engineering, such as bridgehead jumping, soft foundation subsidence, tumbling, landslides, etc. It has the characteristics of light material, abrasion resistance, aging resistance, chemical corrosion resistance, wide temperature range, high tensile strength, good rigidity, good toughness, strong impact resistance, relatively stable size, and convenient transportation.
At present, the proportion of new roads in the district is decreasing year by year, and the reconstruction and expansion projects are increasing. The Qingyin high-speed reconstruction and expansion project applies the plastic geocells factory price to the new and old subgrade connections for the first time to deal with the uneven settlement of new and old roadbeds and the filling of high-filled roadbeds. Provided technical support for the better and faster completion of the Qingyin high-speed reconstruction and expansion project. In order to improve the national highway network, implement the strategic deployment of the western development, and complete other renovation and expansion projects in the region, it has played a guiding role. The technical strength of Ningxia Road and Bridge Engineering Co., Ltd. has made outstanding contributions.
2. Basic overview
Ordinary plastic geocells manufacturers is a new type of geosynthetic material made by high-frequency welding of HDPE broadband. It uses its three-dimensional confinement principle and is suitable for foundation reinforcement, cushion, and surface protection. It is a three-dimensional structure and is changed by The combination of depth and hole type allows for a rigid or semi-elastic plate that greatly enhances the load-bearing capacity of soft, loosely-packed materials.
The method of conventionally treating the roadbed in the project aims to improve the shear resistance and friction of the foundation material. It reduces or delays the ability of the foundation material to move under the pressure or vibration of the load. Therefore, there are many strict restrictions on the material requirements in the project. If the required materials cannot be obtained nearby, it is necessary to purchase these materials and purchase the materials. Costs and shipping costs account for a significant portion of the overall project cost. With plastic geocells factory price, materials can be taken locally or nearby, and even materials that are not normally used can be used, thereby significantly reducing material purchase costs and shipping costs. In short, the plastic geocells manufacturers has the comprehensive effect of cushioning, reinforced, drainage, regulating stress and deformation, and improving the impermeability of the soil.
3. Scope of application
high quality plastic geocells can be widely used in railways, highways, deserts, swamps, tidal flats, airport soft foundation treatment, and slope protection, and can also be used to control landslides, retaining wall construction, abutment jumping, and can also be used in cities. Greening vegetation protection. In the 4th contract section of the Qingyin Expressway Reconstruction and Expansion Project, in addition to the low-filling section, the filling height is less than 6m, and a layer of steel nails is inserted into the integral plastic geocells manufacturers, and the filling height is more than 6m. A layer of integral high-strength high quality plastic geocells is laid on the next step. Soft soil and collapsible loess widely exist in the construction of highway engineering in our district. The application of the fourth contract section of the Qingyin expansion and expansion project has played a leading role in other projects.
4. Application instructions:
4.1 Materials
The 4th contract section of the Qingyin Expressway is made of high-density polyethylene as a raw material, which is extruded into a sheet and welded into a three-dimensional network structure. High-density polyethylene HDPE is a kind of polymer material with good performance. Compared with low-density polyethylene (LDPE), it has the advantages of high crystallinity, high softening point, high modulus, and high strength. Its low-temperature performance is especially outstanding. It maintains its flexibility in a cold environment of -60 °C.
4.2 Construction process
4.2.1 Preparation before laying out
(1) The purchased high quality plastic geocells material must have a factory certificate and test report. Every 5000m3 should be randomly sampled for strength index test, and the results must meet the design requirements. The design of the fourth contract section of Qingyin’s expansion and expansion requires the fracture force of the unit width of the plastic geocells manufacturers to be 16KN/10cm, the fracture tension of the joint between the chambers is 16KN/10cm, and the joint resistance of the joint is ≧16KN/10cm. Level and compact the roadbed to the required degree of compaction as required by the construction code.
(2) U-shaped nails are manufactured, the diameter of the U-shaped nails is mm2.5mm, and it must be galvanized and treated.
4.2.2 Layout and hanging network
(1) The connection between high quality plastic geocells: Before the plastic geocells factory price is untensioned, connect the cells with cell connectors.
(2) Pull the cell to make the cell in a tension state, and do not allow a feeling of relaxation.
(3) At the beginning of laying the plastic geocells for sale, the prepared U-shaped nails are driven into the subgrade by the hammer according to the size of the plastic geocells for sale, the cell height is 50mm, the grid size is 40×40cm, and the U-nail is not exposed. The height of the room.
(4) The width of the plastic geocells for sale is laid according to the design requirements.
(5) Pull the connected plastic geocells factory price to the specified size and use U-shaped nails or manual fixing to prepare the fill. After the plastic geocells for sale is laid, it should be filled immediately on it, and it is strictly forbidden to expose it.
4.3 Filling
(1) Fill the soiled cell room in the tension direction from the transverse end of the cell. When filling the soil, it should be noted that the dump truck is strictly prohibited to travel above the plastic geocells manufacturers without filling. Check the cell for damage before filling. If it is, it should be disposed of immediately.
(2) The thickness of the dummy fill of each layer of filler is not more than 30cm, but it should not be less than 25cm. After the filler is leveled, it can be crushed, and the packing compaction degree is controlled by 93%. When filling the loader, the thickness of the loader must be more than 10 cm above the cell to prevent damage to the cell.
(3) Restoring the pile in the route, determining the embankment filling boundary according to the design chart and the actual ground elevation (to ensure the road shoulder compaction degree, each side is widened by 30-50 cm), and determining the thickness of the filling layer according to the corresponding looseness coefficient. Piles (pitch 20m, gradient segment encryption), the layer thickness is marked on the side piles and connected with nylon rope to control the filling width and layer thickness.
4.4 leveling and rolling
Rolling: Check the thickness, flatness and water content of the looseness before rolling, and quickly carry out the rolling after meeting the requirements. When rolling, it should be followed by light and heavy, first stabilized and then oscillated, first low and then high, first slow and fast and the wheel track overlap, etc., from the two sides to the middle longitudinal advance and retreat, the transverse joints generally overlap 1/3 of the wheel tracks The adjacent sections should be longitudinally overlapped by 1.0 to 1.5 m. No leakage, no underpressure, no dead ends.
4.5 Inspection and acceptance
Check the filler thickness, flatness, and fill boundaries as required by the design.
5. Characteristics of construction methods
(1) The method has a wide application range, simple construction method, a wide range of raw materials, easy control of quality and strong operability.
(2) Lightweight, abrasion resistance, aging resistance, chemical corrosion resistance, wide temperature range, high tensile strength, good rigidity, toughness, strong impact resistance, relatively stable size, and convenient transportation.
(3) The connection is simple and easy to construct during construction, and the construction method is simple plastic geocells for sale, thereby simplifying the construction process and improving the construction speed, and it can be used repeatedly.
6. Construction reminder:
(1) The tension of the cell during the laying process is the key. Make sure that the cell is in tension and there is no slack.
(2) Determine the quality of the compaction of the filling to meet the specifications.
(3) If it is a soft base, make sure there are drainage facilities.
Conclusion
With the rapid development of highway construction in our district, the construction technology of using plastic geocells factory price to treat soft soil and collapsible loess foundation will be more widely used in the whole district. Under certain conditions, geotechnical chambers are superior to conventional shallow foundation treatment methods in dealing with soft soil, collapsible loess foundation labor intensity, construction progress, and treated foundation technical properties, saving time and effort. And can greatly reduce the project cost. Through other similar projects and the practice of this project, it is proved that the use of high quality plastic geocells to treat soft soil and collapsible loess foundation and control the construction quality, in order to solve the problem of the foundation bearing capacity reduction caused by differential settlement of soft foundation, will be A scientific, efficient, economical, environmentally friendly and feasible construction technology program.