RU2039158C1 - Method for erecting piles in permafrost ground - Google Patents

Abstract

FIELD: civil engineering; building construction. SUBSTANCE: method involves drilling a well, inserting a pile into the well, filling the space between the pile and well walls with frozen water-saturated pieces of soil. The next step involves melting the upper portion of the space until the level of ground mass arisen as a result of melting exceeds the level of pieces of frozen soil. EFFECT: enhanced stability and simplified construction process in building structures on permafrost ground. 4 dwg

Description

 The invention relates to construction and can be used in the construction of pile foundations for buildings and structures and the installation of anchor devices for securing pipelines in permafrost soils.

 A known method of construction of piles in permafrost soil, including drilling a well, installing a pile shaft in it with filling the space between the wellbore and the walls of the well with water-saturated soil, followed by freezing it.

 This method is the closest to the proposed and adopted as a prototype.

 The disadvantage of this method is the presence of "wet" processes associated with the delivery to the place of work of warm water, crushed soil and mixing them to the required consistency at the construction site and pouring into the well, which is time-consuming at low temperatures during work in permafrost soils.

The objective of the present invention is to remedy these disadvantages, namely: increasing productivity by saving thermal energy with incomplete thawing of pieces of frozen soil;
the exclusion of "wet" processes for the preparation and filling of the soil solution into the well;
elimination of the need to develop and grind the soil for the preparation of soil mortar;
exclusion of transportation costs for the delivery of crushed soil from the quarry to the place of work.

 In FIG. 1 shows the initial stage of well drilling; in FIG. 2 well with a pile shaft installed in it, in section; in FIG. 3 the same, with the filling of the space between the wellbore and the walls of the well with pieces of frozen, water-saturated soil; in FIG. 4 the same, thawing of the upper part of the space between the wellbore and the walls of the well.

 The method is as follows.

 Screw 1 of a drilling rig in a permafrost soil drills a well 2, into which a shaft 3 of a pile is lowered. The space between the barrel 3 and the walls of the well 2 is filled with pieces of frozen water-saturated soil 4. Then, the upper part of the indicated space is thawed with steam supplied through a steam needle 5 to exceed the level of the ground mass released during thawing over pieces of frozen soil.

 In the process of thawing pieces of frozen soil in the upper part of the space between the pile shaft and the walls of the well, a thawed water-saturated ground mass is formed, which flows down, penetrating between pieces of frozen unfrozen soil. Warm water, which was formed during the condensation of steam, also flows down. Gradually, a water-saturated ground mass fills the voids between incompletely thawed pieces of frozen soil throughout the depth of the well and rises above their level. Exceeding the level of soil mass released during thawing over pieces of frozen soil is a control indicator for completing work.

The restoration of negative temperatures in thawed soil (freezing) occurs within 2-3 days. During this time, the following processes occur:
thawing of pieces of frozen soil in the lower part of the well continues under the influence of heat transfer from the upper layers of thawed soil with the formation of an additional volume of thawed soil;
water-saturated ground mass is consolidated with mineral particles settling down and free water being pushed up;
in the lower half of the well, a structure is formed from thawed soil of plastic and fluid consistency with inclusions of frozen pieces of soil that have not had time to thaw completely.

 After freezing the soil, pieces of frozen soil are frozen into a water-saturated soil mass. Due to this, the volume of soil to be frozen is significantly reduced and, accordingly, the time of freezing is reduced. This allows you to use the method for the construction of piles in plastic frozen soils.

 The method is especially effective in the construction of linear structures in frozen ground, for example, for dipping anchors and piles when laying pipelines and building power lines.

Claims (1)

 METHOD FOR PILING IN A PERMANENTLY FROZEN SOIL, including drilling a well, installing a pile shaft in it with filling the space between the well and the walls of the well with water-saturated soil, followed by freezing it, characterized in that the space between the well and the walls of the well is filled with pieces of frozen and saturated water, then thawing of the upper part of the space to exceed the level formed during thawing of the soil mass over pieces of frozen soil.

Images