SU1435702A1 - Method of thermal consolidation of swelling soil - Google Patents

Abstract

The invention relates to the field of construction, in particular to the strengthening of swellable soils, underlain by dust and other sand, thermal exposure, and is aimed at accelerating the process. This is achieved by the fact that in the well-known technology, including the formation of wells, the compaction of soil on their walls, the sealing of mouths, the generation of hot gases in the wells, the injection of the latter into the soil through the bottom of the wells and. heating the soil with its drying, before generating a stream of hot gases, drilling vertical holes between wells and their subsequent filling with drainage material. After the soil is heated, it is compacted around the estuaries, and the formation of wells is carried out over the entire depth of the swellable soil with their expansion upwards. 1 ill., 1 tab.

Description

four

from the next

. The invention relates to the construction, in particular to the strengthening of swellable soils, underlain by silt and other sands, thermal effects.

The purpose of the invention is to accelerate the process.

The drawing shows a diagram of the implementation of the method.

The method consists of the following operations.

The wells 1 are distributed together with the boreholes 2 evenly over the entire depth; the bin 3 of the swellable soil, and the walls 4 of the wells 1 are compacted with their 5 widening from the bottom 6 to the mouth 7 with known devices, and then the wells 1 are sealed with valves 8 with pipes 9 connected by valves 10 with generators 11 of hot gases. After that, the holes 2 are filled with drainage material 12, for example sand, the entire system is checked for tightness and hot gases are injected into the soil through the bottom of 6 wells 1, which are filtered and flow from the underlying horizon 3 through holes 2 through the drainage material 12 13 and directly through reinforced swellable soil 14 due to the pressure difference in the atmosphere. The soil 14 is heated to the evaporation temperature of the moisture contained in it and dried, which is set upon termination of steam generation from boreholes 2 to the atmosphere. Then the soil around the mouths of the 13 holes 2 is compacted, for example by tamping, and the soil 14 is heated until it reaches a predetermined temperature, for example 400-500 ° C, to eliminate the swelling of the soil 14, which is checked by the thermocouple readings 15 bore holes 2, and recording devices 16.

Uniform placement of wells and bore-holes ensures the symmetry of the gas and water flows, excluding the accumulation of moisture in local soil volumes and its uneven deformation. Cutting wells and sprues throughout the entire thickness of the swellable soil makes it possible to direct the flow of hot gases from the bottom up, using the filtration capacity of the underlying horizon, consisting of various sands, and create the largest pressure gradient for moisture migration from the massif to the drill holes. Filling the drill holes with drainage material ensures even suction of moisture from the massif, prevents the destruction of the structural bonds of the soil and local accumulation of moisture and prevents the walls of the drill holes from melting.

The conical shape of the wells provides an increase in the rate of hot gases to the bottom of the well 5

0 0 Q 5

0 g 0

This intensifies the process of carrying out and the subsequent heating of the soil, and the compaction of the walls reduces the filtration of gases into the soil mass. Sealing the surface of the soil around the hole mouths creates additional accumulation of thermal energy and eliminates heat loss to the atmosphere.

Such a technology of the proposed method allows to increase the pressure in the wells to 0.4-0.8 MNa and speed up the process of soil acceleration.

Example. At the construction site, thermal strengthening of the swellable soil — clay with a porosity factor of 0.83 and a plasticity number of 21, with a depth of 6 m — underlain by silt sand is carried out. Three massifs with a volume of 192 m are reinforced. In each massif four skaginas are drilled: and nine holes. The wells were made with a diameter of 0.2 m, the boreholes - 0.08 m. The wells were sealed with a tapered leader with a diameter broadening of 0.2 to 0.3 m at the top. Local sand is used to fill the holes. LBK-50 units, USV-600TM heaters with a maximum temperature of hot gases up to 600 ° C, thermocouples ТХА-УШ, devices ППГ1-9М2 are used for works. In the wells of the massifs, respectively, support excess LT, avle1; ne 0.4 --0.6-0.8 MPa.

The results of the work .ch their comparison with the parameters known about the method are given in the table.

Thus, the proposed method allows the use of thermal strengthening of soils to eliminate their swelling in the foundations of buildings and structures and speed up the process of strengthening the soil 1.2-1.6 times.

Claims (1)

Invention Formula The method of thermally strengthening the swelling soil, including uniformly compaction of the soil over the walls of the soil and sealing of the mouths, generating a flow of hot gases in the wells, forcing the latter into the soil through the bottom of the wells and heating the soil with its purpose process, before generating a stream of hot gases, vertical holes are drilled between the wells and their subsequent filling with drainage material, and after heating the soil nenie around the mouths of the holes, with the formation of the wells are in the full depth of swellable soil with their extension upwards. 9 - .- i