One way to improve the properties of soils is their reinforcement by different geosynthetic materials. Difficulty an objective assessment of the effectiveness of the use of geosynthetics in construction is its one of the reasons preventing their wider application. Conducting research aimed at studying the work of geosynthetic materials in the construction of foundations and their interaction with the ground, is a very costly and time consuming practice. The tests of reinforced soil structures for transport construction, which are influenced by dynamic loads are particularly complex. Geosynthetics can significantly improve the deformation characteristics of reinforced soil bases. Therefore, the use of different express methods for determination of deformation characteristics of reinforced soil bases is very important. Method using the dynamic densitometer is a new express methods for determining the deformation characteristics of subgrade. «Meter ground dynamic modulus DPG-1.2» was used as an apparatus for determining the dynamic modulus of elasticity Ed on the ground surface Dynamic modulus of elasticity Ed has a correlation dependence with a coefficient of compaction and static modulus of elasticity Est . One application of geosynthetic material in road construction is their use in the construction of temporary roads. Therefore, the construction of temporary road, representing a layer of sand of various thickness on the reinforcing geosynthetic interlayer modeled in this work. The carcass geogrid KS-16 «Rossomaha» production on JSC ««Krasnokamsk Metal Mesh Works» «and geotextile Geospan TN-50 manufactured by Ltd «HEXA-woven materials» were used as reinforcing geosynthetics. This article presents the results of the determination of the static modulus of elasticity Est and dynamic elasticity modulus Ed soil reinforced by geosynthetic material and soil without reinforcement using DPG-1.2 device. As a result of the experiment shows that the modulus values obtained with the express method of using the device-DPG 1.2 are comparable with the values of data obtained by the laboratory method, the measurement error does not exceed 22 %. For backfill thicknesses h = 50 mm use the carcass geogrid KS-16 can increase Est by 23 % and Ed by 14 % compared with the unreinforced base. Using the geotextile Hexa TN-50 can increase Est by 15.5 % and Ed by 11 % compared with the unreinforced base. Increasing the thickness backfill h up to 100 mm is practically not reduce the effectiveness of the reinforcement carcass geogrid KS-16 «Rosomaha» - static modulus E st is increased by 22 % and dynamic modulus Ed by 14 % compared to the unreinforced base. And for the geotextile Hexa TH-50 at h = 100 mm reinforcement efficiency is greatly reduced - the value Est and Ed only increased by 2.5 % compared with the unreinforced base. This is probably caused by a significantly greater rigidity carcass geogrid KS-16 «Rosomaha» Thus DPG-1.2 device allows accurately measure the deformation characteristics of soil bases. The use of specialized carcass geogrids KS-16 «Rossomaha «more effectively in the construction of temporary roads in comparison with universal geosynthetics Hexa TN-50.
DETERMINATION OF DEFORMATION CHARACTERISTICS OF REINFORCED SOIL BASE BY EXPRESS METHOD USING DYNAMIC DENSITOMETER