بررسی رفتار واحد مسلح کننده سلولی (ژئوسل) تحت بار استاتیکی

Geological and site investigations in the world indicates that there are too many fields with soft soil. The existence of such soils in construction sites of buildings may create numerous problems for the foundations, for example the circumstances of roads, foundations and etc. Symmetrical and unsymmetrical settlement of foundations in soft soil areas may destroy even best constructions.

Three dimensional geosynthetics could significantly improve the performance of soil and reduce the costs compared with conventional methods. In this article the behavior of this system has been investigated under vertical load in granular soil for the gap between the applications and the design theories of reinforced base with geocell. Although the geocll system behavior and the effects of adjacent cells on central cell is one of the cases that has not been studied sufficiently.

In this article, the results of the plate loading tests on geocell reinforced sand bases have been studied, and the behavior of three dimensional cellular unit and the effects of adjacent cells have been considered as well. The effective parameters include the diameter and the number of cells. The test sample was a wooden box with 90 cm length and width and 60 cm height filled with poorly graded granular sand. In this study, geocells have been created by sewing the non-woven geotextile in a symmetrical pattern and dimension, and cells diameter were 12, 15, 17.5 and 22.5 cm. The strain gages were attached in order to eliminate measurement errors. The loading processes were carried out by a steel loading plate with 15 cm diameter.

In this investigation besides the considering the geocell behavior, the optional design parameter of this system has been considered with the purpose of decreasing the settlement. Also, the non-woven geotextiles has been sewed in a symmetrical arranged pattern and the behavior of one-cell and multi-cell geocell has been compared. In order to evaluate the failure mechanism of geocell, the novel method of strain gage installation in nonwoven geotextile has been used.

The results include the bearing capacity, the soil surface and cells deformations under a vertical loading. The results indicate that the cells which have a diameter equal to the loading plate have better performance than the others. Also it has been clarified that the existence of adjacent cells with the diameter of 0.8 times the diameter of loading plate, are more suitable for eliminating the settlement. It is also observed that the cells which are smaller than the loading plate, encountered more deformation than the bigger ones.

Also it has been proved that one-cell geocell with the diameter equal to the diameter of loading plate, improve the bearing capacity and base stiffness more than one- cell and nine-cell with diameter equal to 0.8 and 1.7 times of the loading plate diameter. It can be concluded that if the loading position was fixed, one-cell geocell wih diameter equal to foundation diameter is recommended. For moving loads (car load on road), geocell with diameter less than diameter of loading plate should be used.