Spiral pile of large and small diameter in the construction

Screw anchor piles and may be used in various soil conditions except rock. They make it possible to avoid the time-consuming work on the digging of pits. Foundations of the screw and the anchoring piles compared with the conventional possess a number of significant advantages. The most important of which are low in material and labor, the complete absence of excavation, preservation foundation soils in the natural state, unstressed immersion, high precision installation in horizontal and vertical. Especially screw piles and anchors are suitable in flooded soils.

Screw piles are used in the foundations of power lines, poles contact network of railways, with the construction of cell phone towers in the construction of oil and gas pipelines in the wetlands, subsidence and heaving soils, with collapsible construction, temporary bridges and piers, as well as the foundations of low-rise buildings .

Experience of foundation on screw piles and anchoring demonstrated their reliability and high environmental performance, the possibility of year-round use of the construction works.

The institute of “Sevzapenergosetproekt” developed a model project “Screw piles, anchors and foundations on screw piles” [1].

Analysis of the experimental work in our country and abroad will develop recommendations for the design and manufacture of screw piles and anchors the optimal parameter immersed without prigruzhajut efforts. The optimal parameters of screw terminals.

Screw piles in construction

Picture 1. The machine UBM-85.

Currently, the technology of fabrication of welded screw tips and cast carbon steel VStZsp5, 09G2S and low YuhSND and 10G2SKH.

Tightening pile (anchor) of large diameter is recommended not less than 4.0 m for reasons of reliability. As for the piles of small diameter, dip them should take into account the depth of freezing, as well as the calculated bearing capacity.

The calculation of the carrying capacity of screw piles to compressive load and pulls us set out in the Interuniversity collection of Civil Engineering in 2006 pp. 37-41. [4]

With a small amount of work immersion screw piles can be carried out using a mechanical rope capstans winches skidders, trucks and mobile cranes.

Well established and gidrokabestany which are mounted as a removable equipment for excavators E-14 (E-18) with a bucket capacity of 0.5 m3 [3]. The most promising is the machine UBM-85, manufactured by JSC “Plant Stroydormash” [3].

The machine is designed to perform work on the foundation on screw piles, anchors and immersion drilling wells continuous screw diameters from 200 to 800mm and a depth of 6.0 m. The main units of the machine are:

  • three-piece telescopic boom with providing a range of missions working in the range of 1.8 to 12 m;
  • column installed on slewing bearings;
  • frame with hydraulic outriggers and the loading platform.

In the transport position dimensions of the machine allow it to move freely on public roads.

UBM-85 is equipped with electro-gidgavlicheskoy security system based on a microprocessor, which allows the operator to control the load in the process of screwing with the possibility of fixing options. The testing of the data and fixing the depth of immersion, the moment of resistance on the pile and its bearing capacity.

The technology of using UBM-85 is fundamentally different from that used by other devices for piling. The characteristics of UBM-85 – maneuverability and ease of use and high performance.

This machine is often used at different sites during the construction of foundations on screw piles of large diameter. Time screwing piles to a depth of 5-6m composes only 4-5 minutes.

Along with screw piles with welded screw tips [3] “Plant Stroydormash” manufactures screw piles with cast screw caps. General view of the pile is shown in Picture 2. The main parameters and dimensions of screw piles are shown in Table 1.

Screw piles in construction Screw piles in construction

Picture 2. Piles of steel screw with cast and tip) for thawed soils; b) for the permafrost.

Table 1.

Screw piles in construction
* Admission to the size of the requirements of GOST 8732 “Pipes steel seamless hot”.
** Determined calculations.

Screw piles for conventional (thawed) and permafrost are certified and can be widely applied in construction.

To install the supports of type POM-220, are in poor condition, in the design position and enable their further exploitation,

Screw piles advisable to use in the repair of bearings BL [1], especially in emergency condition. So on BL 220 kV Medvezhyegorsk – Onda (Karelenergo) repaired the foundations of metal poles POM-22C).

Screw piles in construction

Picture 3. Foundations on screw piles to support GTOM-220.

JSC “Institute Sevzapenergosetproekt” drafted a new foundation with metal screw piles and installation of its technology, which allows all the work without shutting down the power lines. New foundation of the SIP-220 and GYUM 220 ± 5 (Figure 3) is a structure of four screw piles (4), United raft consisting of two longitudinal beams which are rigidly attached to the screw piles and cross beam (6) attached bolted to the middle longitudinal bars. Belts are made of beams channels, struts – out of angles. All elements of the pile cap are interconnected by means of bolts. In the middle of the cross beam mounted hinge assembly (7), which provides turn support rack in which the axle beam in a plane perpendicular to the axis of the beam. Foundations are designed for load bearing POM-220 + 5 in the second set and the first wind gust district, which suspended wire brand ACO-400 and C-50 cable. Making foundations and screw piles was carried out in AT JUKES JSC “Karelenergo”.

Another example of the use of screw piles on BL 330 kV “Estonian TPP – Kingisepp” was to restore health emergency support by replacing fastening braces with anchor plates on the screw foundations.

Disabling BL 330 kV was due to breakage backstay support number 150 and its podhlestki the extreme phase. Prop – reinforced concrete at the intermediate single-shelf braces.

Immersion screw piles trunk diameter of 203mm and 800mm blade was made from ice rope Ratchet per shift, rewiring guys repair conductors – in two shifts. Production of devices for piling at the St. Petersburg company MEA took three shifts.

As a result, it did not need to pour banquette 15000 m3 in the reservoir and mount a new metal support tower using a plank on the foundations otsypnoy banquette dismantling supports in-ZZO. The cost of the new support would have been 500 thousand. Rubles.

Our colleagues in the Ukraine (the magazine “Elektrobud” the authors Pateyuk NG Ph.D., Eng. Kostikov VI) Recalling our development promoting the use of screw piles and anchors the company “A.V.Chance” multiturn piles of small diameter and drilling and crane equipment. However, it should be noted that the design of screw piles firm “A.V.Chance” is a far suboptimal and costly. Coils of 101-381mm diameter piles with a constant pitch, increases only strength, but not the load-bearing capacity of the ground.

Construction screw piles institute “Sevzapenergosetproekt” with spaced optimum value lopostyami increase the carrying capacity of the pile on the ground by 25-30%.

In our view, it is expedient to use in the construction of screw piles relatively large diameter in the range of 0.5 – 0.85 – 1.0 m.

Piles of small-diameter blade 300 mm and 108 mm barrel is very suitable for cottage and cottage construction, as they allow to screw them by hand four workers. Screw piles of this parameter are the best option for foundations timbered, panel and frame houses.

Foundations on screw piles of small diameter manages customer 1.5-2 times cheaper than tape, not to mention the monolithic slab.

Within one year, the foundations were built on stilts in the screw p.Melnichny Creek (Vsevolozhsk), in gardening near St. Petersburg in Baryshevo and other areas of the Leningrad region (Figure 4).

They can be used in berths in greenhouses foundations, various protections.

Screw piles in construction Screw piles in construction

Picture 4. Examples of application of the small-diameter screw piles in the construction of various objects.

Screw piles in construction

Conclusions:

  1. The use of screw piles and anchors in building appropriate. Screw piles significantly reduce the volume of construction and reconstruction work, especially in accidents and other emergencies.
  2. Screw piles in construction and cellular shall apply only large diameters. Screw piles of small diameter is useful for a relatively small loads (substations, the foundations of low-rise buildings, strengthening the foundations plank in the swamps and in other. Cases).
  3. In the manufacture can be used as a welded or cast construction screw piles.
  4. The new technology immersion of screw piles gidrokabestanami and special installations UBM-85 (plant “Stroydormash”), features technology using UBM-85 are the maneuverability, cross-country off-road and ease of use.
  5. At present, there is the need to develop a set of rules which set out a revised methodology for calculating the screw piles and anchors, reflecting the real work in soil conditions. This will eliminate the disadvantages of SNIP 2.02.03-85, and thus achieve a significant economic effect.

Literature:

  1. В.Н. Железков. Монография. Винтовые сваи в энергетической и др. отраслях строительства. Санкт-Петербург, изд. дом Прагма, 2004 г. – 128 с.
  2. С.Н. Петухов. Фундаменты на винтовых сваях для малоэтажного строительства. Отдельный выпуск.
  3. В.Н. Железков, Г.В. Сиволобов, Б.А. Иванов. Закрепление опор BJI и контактной сети железных дорог с применением винтовых конструкций в обычных и вечномерзлых грунтах. Основания и фундаменты: теория и практика. Межвузовский тематический сборник трудов. Санкт-Петербург, 2004 г., 67-76 с.
  4. В.Н. Железков, Л.H. Качановская. Винтовые сваи в строительстве. Геотехника: актуальные теоретические и практические проблемы. Межвузовский тематический сборник трудов. Санкт-Петербург, 2006 г., 37-41 с.

Comments are closed