In order to design civil structures that are supported by soils, the shear strength parameters of soils are required. Due to the large particle size of coarse-grained soils, large direct shear tests should be performed. In this study, large direct shear tests on three types of coarse grained soils (4.5 mm, 7.9 mm, and 15.9 mm) were performed to evaluate the effects of particle size on the shear...

By installing FBG sensors on the geogrids, smart geogrids can both reinforce and monitor the stability for geogrid-reinforced slopes. In this paper, a geogrid-reinforced sand slope model test is conducted in the laboratory and fiber Bragg grating (FBG) sensing technology is used to measure the strain distribution of the geogrid. Based on the model test, the performance of the reinforced soil sl...

The geogrid-reinforced soil structures play important roles in the reinforcement applications since 1980s. Generally in design of the geogrid-reinforced soil structures, the soil-geogrid interaction behavior is not directly considered. Instead, the interaction strength is represented by the consolidation drained strength of soil commonly. However, neglecting the effect of compaction and suction...

The increase of shear strength in soil, reinforced with the geogrid (alternate reinforcer), is resulted from an increase of modulus of soil hardness, and also from the tensile strength of reinnforcer. The shear strength of contact surface in soil appears due to both the friction strength against the contact surface, and the passive strength formed in front of the elements of the geogri...

In this paper, an experimental and numerical study was adopted to investigate the effect geogrid soil reinforcement prestressing on the pressure settlement relation of sand bed supporting a strip foundation. The studied parameters include foundation depth and pre-stress ratio for the cases of one and two pre-stressed reinforcement layers. The study reflected that pre-stressing of soil reinforce...

In the present study, physical model tests were conducted to investigate the effect of the geogrid reinforcement on the reduction of the differential settlement in widening of a highway embankment. A water bag filled with water and placed beneath an embankment was used to simulate the soft foundation of the widened portion of the embankment in the physical model test. Water from the water bag w...

This paper tries to study the effect of geosynthetic inclusion on the improvement of the load-settlement characters of two layered soil. In addition, the effect of geogrid and geotextile in reduction of the required thickness of subbase layer in unpaved roads is studied. Considering the vast application of bearing ratio tests in road construction projects, this test is used in present investiga...

abstract: this paper presents the results of pullout tests on uniaxial geogrid embedded in silica sand under monotonic and cyclic pullout forces. the new testing device as a recently developed automated pullout test device for soil-geogrid strength and deformation behavior investigation is capable of applying load/displacement controlled monotonic/cyclic forces at different rates/frequencies an...

in this research, failure mechanism, soil deformation and effect of reinforcement below a strip foundation were studied using physical modeling and piv method. for this purpose, a comprehensive set of tests were undertaken on dense and loose sands and different geosynthetic materials such as geotextile and geogrid for soil reinforcing. in each step of loading, digital image of deformed soil was...

The stability of geogrid-reinforced soil structure is closely related to the interface characteristics between geogrid and soil. However, creep behavior soil–geogrid still unrevealed. In this study, using a modified stress-controlled pullout device, influence normal pressure, dry density, water content on compacted loess high-density polyethylene (HDPE) investigated. A three-parameter empirical...