SU1006608A1 - Method for thermally consolidating soil - Google Patents

Abstract

A THERMAL METHOD IS STRENGTHENED BY THE 1ST SOIL, including the formation of the main and auxiliary wells, sealing the wellhead of each well, evacuating the wells to remove water from the reinforced soil mass, burning the combustible mixtures in the main well and pumping hot gases through it into the ground while simultaneously maintaining the vacuum auxiliary wells before the appearance of steam in them, characterized in that, in order to increase productivity, the formation of wells is carried out in the form of slots of rectangular cross section with parallel The longitudinal axes of the cross sections, after the formation of each auxiliary well, seal its wall, which is oriented outward from the reinforced massif, and after the occurrence of steam in the auxiliary wells, combustible mixtures are injected and hot gases are injected into the soil. About to about SH)

Description

The invention relates to the construction and can be used in the strengthening of the foundations of buildings and structures by thermal exposure of the soil, as well as in the construction of retaining and other walls, mainly in bonded soils. The known method of thermal soil stabilization includes the formation of main and auxiliary wells, blowing soil with compressed air, supplying combustible mixtures to the main well, burning them and pumping heated gases into the soil 13. The disadvantage of this method is inefficient use of energy and time to remove from the array gro that moisture. The closest to the invention is a method of thermally strengthening the soil, including the formation of primary and auxiliary wells, sealing the mouth of each well, evacuating wells with removing water from the reinforced soil mass, burning in the main well of combustible mixtures and forcing hot gases through it into the soil while maintaining a vacuum in auxiliary wells until steam appears in them 2. However, the method has a relatively long duration of thermal strengthening due to the small heat transfer surface through the walls of the main well and forced suction of moisture from the soil mass outside the auxiliary wells, which slows down the strengthening process. The purpose of the invention is to increase productivity. This goal is achieved in that according to the method, including the formation of primary and auxiliary wells, sealing the mouth of each well, evacuating wells with removal of water from the fortified soil mass, burning in the main well of combustible mixtures and forcing hot gases through it into the soil while maintaining vacuum in auxiliary wells before the appearance of steam in them, the formation of wells is carried out in the form of slots of rectangular cross section with a parallel arrangement of longitudinal. After the formation of each auxiliary well, the axes of the sections are sealed off its wall, facing outward from the reinforced massif, and after the appearance of steam in the auxiliary wells, the combustible mixtures are burned in them and the hot gases are injected into the soil. FIG. Figure 1 shows the wells, the reinforced soil massif, the network layout and equipment layout; FIG. 2 - the same plan. The technology of the method is as follows. First, the main 1 and auxiliary 2 wells are formed in the form of semi-angular sections of the slots, that is, the location of the subsequent rows of wells 1 and 2 is determined from the ratio,, (1) where d is the soil roasting rate, m- / h; T - the duration of firing, h; H is the depth of the wells, m, 8 is the width of the slots of the wells, m. Then the outer walls 3 of the auxiliary wells 2 are sealed. For example, soil compaction. Synthetic and other materials can be used as sealants. After that, wells 1 and 2 are sealed with valves, with nozzles 5 placed on them, intended for connection to external networks and installation of burners. Vacuum lines 6 are connected to nozzles 5 with vacuum pump 7 and the reinforced soil massif 8 is drained by removing water from it through the main 1 and secondary 2 wells, until the soil moisture is reduced to the limit at the border of rolling out, which is determined by testing selected from the reinforced array of 8 soil samples. Then, the main 1 is disconnected from the vacuum line 6 and the nozzle 5 of the gate 4 is equipped with a burner, fuel is supplied through the well 1 from the tank E and compressed air from the compressor 10, the resulting combustible mixture is burned and the hot gases are injected into the reinforced soil mass 8, continuing simultaneously evacuating from auxiliary wells 2 until steam generation begins in them. After that, the nozzles 5 valves k on% auxiliary wells 2 are also equipped with burners and combustible mixtures are burned in auxiliary wells. The injection of heated gases into the ground is stopped after the pressure, when at the least heated points of the reinforced soil massif 8 the temperature does not reach the calculated one. This moment is determined with the help of thermocouples mounted on the soil massif 8, connected with self-recording instruments (not shown -). Replacing the cylindrical shape of a well with a rectangular one increases the surface of transfer of heat energy to the ground, and the area of vacuuming of moisture and its vapors increases through the main 1 and auxiliary 2 wells. Sealing the outer walls of the auxiliary wells 2 makes it possible to reduce the suction of moisture from the soil outside the reinforced array 8 during the period of vacuuming through the auxiliary wells 2, and during the injection of hot gases through them, their output beyond the boundaries of the strengthened array B decreases. ground. The use of auxiliary wells 2 for burning the soil after the removal of moisture from them evacuation reduces the duration of thermal strengthening. Example. Thermal reinforcement of cover loam with a capacity of 8 m, natural moisture content of 0.32 was produced at the experimental work site. According to the experiments, the speed of pressing is 0.6, the limit of rolling of the pile is 0.1. At two sites, plots are made in plots of width m. At each of them, two main and four auxiliary wells are made in the form of slits 0.2 m wide, 2 m long, with distances between a number of wells equal to 1.1 The drilling operations are carried out with the help of mounted equipment; 1 the equipment to the excavator E-1254. After that, the soil on the external walls of the auxiliary wells is compacted with a mechanical device, the wells are sealed and connected to the HB-50 vacuum pump. The evacuation of air and water from the array of soil lead 10-12 hours, until the soil moisture reaches 0.1. Then, vacuuming is continued only from auxiliary wells, and the main ones are connected to sources of fuel and compressed air. Liquid fuel is burned with a heat of combustion of 40 mJ / kg in a mixture with compressed air supplied from a Mill-55 compressor with an overpressure of 0.120, 25 MPa. At the same time, the evacuation of the auxiliary wells continues. After 4 hours, vapor release begins. After this, auxiliary wells will be converted to heating wells and the process of thermal strengthening of the soil continues simultaneously from all wells for 5-6 hours, until thermocouples TXA-USh installed in the soil massif, connected to XA type recording instruments, accuracy class 0.5, will not show minimum temperature of heating. The final work, including the drilling of wells with soil, takes about 8 hours at each site. At the same time, the work is carried out under similar conditions and by the known method. The analysis is shown in the table.

. The total duration of the process, h, including: the formation of wells

vacuuming

34

37 7

ten

12

10066086

firing without vacuum

filling wells5 The application of the proposed method in practice will reduce pro- /

The continuation of the table is the duration of thermal soil stabilization by 1.3-1 times.

BUT.

 FIG. 2

Claims (1)

METHOD FOR THERMAL STRENGTHENING OF THE SOIL, including the formation of the main and auxiliary wells, sealing the mouth of each well, evacuating the wells with removing water from the reinforced soil mass, burning combustible mixtures in the main well and injecting hot gases through it into the soil while maintaining the vacuum in the auxiliary wells until a pair of them, characterized in that, in order to increase productivity, the formation of wells is carried out in the form of slots of rectangular cross section with parallel with the position of the longitudinal axes of the cross sections, after the formation of each auxiliary well, its wall is facing outward from the array being strengthened, and after the appearance of steam in the auxiliary wells, combustible mixtures are burned in them and hot gases are injected into the ground. SU „„ 1006608 1006608 2