STRESS STATE OF THE SOIL BASIS FOUNDATION, FIXING SOIL-CLAY-CEMENT PILES, BY RESULTS OF NUMERICAL SIMULATION

Today's interaction buildings with soil base is receiving increasing attention, while considered working together elements of the system "soil - foundation - building" taking into account the geological features of the construction site. In work results of numerical simulation fixing of the soil basis foundation with jet grouting technology. The calculations were performed using the ASSR ?VESNA? using a nonlinear model of soil environment. Were considered soil conditions presented by sandy and clay soils in water-saturated condition before and after fixing of the soil-clay-cement piles. Almost 90% of Ukraine exposed to difficult geological conditions of construction, including about 70% of the territory occupied by subsidence soils. Under construction in special soil conditions understand the range of activities related to research, design and installation of bases and foundations on saturated clay and weak peat soils, peat and muds, subsidence, swelling and saline, and uneven compressible soils, loose sand and silt , mines and karst areas in view of seismic and dynamic action. The opportunities of numerical simulation ability at the design stage caused by the settlement system, choice of models of soil environment that most accurately describe the properties and behavior of the soil and make it possible to take into account the hydrogeological aspects of the construction site. The purpose of the work was fulfill the evaluation of the stress state of soil base foundation strengthening soil-clay-cement piles, the results of numerical modeling. In work Strip foundations shallow low-rise buildings with frameless design schemes. In the paper the tape foundations shallow low-rise buildings with frameless constructive scheme. Short description of buildings: floor height of no more than 3 m; foundations rubble a laying of strip with a monolithic plate part depth of 1 m; walls made of brickwork, span up to 6 m; overlapping and coating of hollow plates; roof roll combinations. Depending on the number of storeys of buildings, the following options for per unit length load on the foot of the basement: 200 kN/m, 300 kN/m and 400 kN/m. Calculations performed by finite element method in the flat setting using ASSR ?VESNA?. The work had examined to basics with saturated loam and sand. As the area was considered a possible flooding in case the entire array of water saturation of the soil. This assumption is oriented to the worst combination of factors allows for water saturation foundations rain and meltwater, due to raising the level of ground water soaking emergency basis for the leaking of vodonesuchyh networks. Numerical simulation of stress-strain state of the system "soil - foundation" has shown that the arrangement soil-clay-cement piles at two-side strengthening can reduce the value of stress under the sole foundation for possible water saturation of soil base to 5 times for little loaded foundations (200 kN/m), up to 8 times for medium loaded foundations (300 kN/m), up to 10 times for strongly loaded foundations (400 kN/m). Numerical simulation makes it possible to predict the expected effect of strengthening the foundation by the arrangement soil-clay-cement piles.