Geocell laying method

Preparation before construction:

一．Measurement, stakeout and site cleaning

1. Measure and stake out the construction site according to the construction specifications and design requirements.

2. The original ground shall be cleaned and rolled, and the base treatment shall be the same as that of the general roadbed filling construction. After the treatment is completed and the inspection is passed, the roadbed shall be filled in layers.

3. When the filling height reaches the designed height for laying geogrids and geocells, measure and lay out the lines on the filling surface that has passed the inspection, and determine the location of laying geocells according to the design requirements.

Laying and lap method:

1. Laying of the excavation base: Geocells should be arranged at the height of the excavation and filling in the half excavation and half filling section, and in the combined groove 10cm~20cm deep from the top surface of the road bed.

2. During construction, the geocells should be stretched first, and the side and end of the cable should be fixed with studs, and the adjacent cells should be connected by cell connectors, so that the cells are fully opened, and the center line of the cell coincides with the center line of the line.

3.Backfill the gravel in time, the type of filler: the particle diameter should meet the design requirements, and the filler should not contain sharp edges and corners and

other types of materials that damage the geocell

4.After backfilling, it should be paved and filled manually, and light-duty road rollers are used for rolling. When rolling, the roadside is rolled first, and then the center line

section is rolled, so as to ensure that the cell does not collapse.

5.When laying, use the plug-in connection method to connect the geocell units. When connecting, align the undeployed geocell plastic parts, align the corresponding

connecting plastic parts, insert special round pins, and then unfold.

points for attention：

The stability of geocells in the process of road construction has gradually emerged, and more and more construction companies have purchased this method of geocell reinforcement. In order to improve the construction quality and effectively exert the reinforcement effect of the geocell, it is very important to strictly control the construction process of the geocell, especially in the process of cutting, tensioning and filling of the geocell, pay attention to the following issues:

1. Geocell filler. After the geocell is laid, it shall be filled with materials within half a day and covered within one day to avoid embrittlement and aging of the cell materials caused by strong light and ultraviolet radiation. When filling geocell materials, mechanical and manual filling can be used to improve work efficiency. The materials can be piled into the cell by excavator, and then tamped and paved manually. After the cell is filled with materials, it shall be filled with 10cm thick medium coarse sand or gravel, and then covered with soil. In order to ensure that  the cell is not damaged, 70cm soil must be filled before the roller is allowed to roll and pave the road. In order to ensure the compactness of the fill, it is required to fill according to 3DCM.

2. Geocell cutting. The laying length of geocell must be larger than the subgrade width. When the length exceeds the subgrade width and needs to be cut, the materials in the cell must be filled first and then cut to ensure that the cell does not retract. During cutting, in order to ensure that the materials in the grid are not wasted and leaked, it must be cut along the blank space that has not been filled with materials outside the subgrade.

3. Geocell tensioning. Before on-site tensioning, it is necessary to check whether the geocell is of good quality and completeness, and if it is found to be broken, it should be replaced immediately. When the geocell is tensioned, the tension range should be controlled to ensure that the cell can be restored without being deformed or damaged.

In highway engineering, after the construction of the geocell, the engineering personnel surveyed the settlement results in four times, which lasted for 4 months.

According to the observation results, after setting the geocell as the transition section in the soft foundation treatment section, there is only a slight difference in settlement, which will not affect the subgrade damage. In addition to the settlement  observation, the engineers also conducted on-site observation of the stability of the

two bypass foundations. Through field observation, no cracking phenomenon was found on the top surface of the subgrade and at the corners of the subgrade, which

is basically consistent with the settlement observation results. The setting of the geocell makes the different soft foundation treatment sections settle evenly at the handover position, which ensures the stability and integrity of the roadbed. It can be seen that the geocell can effectively solve the problem of  uneven settlement of the roadbed.