DE112020007357T5 - A METHOD OF TESTING SOILS WITH A POLE - Google Patents

Abstract

The present invention relates to civil engineering, particularly to geotechnical and soil investigations, and can be used for field testing of soils using in situ piles carrying horizontal and moment loads. The method will be most relevant for testing soils using piles, which are structural elements of retaining walls, excavation supports, embankment supports and others, allowing soils to be tested using piles from the surface level rather than the base level of the excavation. The advantage of the method is the preliminary assessment of the stress-strain condition of the pile-soil-base system before starting the substructure of a building, which allows reasonable adjustment of the design of the structures, usually with a significant economic advantage.

Description

The present invention relates to civil engineering, in particular to geotechnical and soil investigations, and can be used for field tests by soils using in situ piles which are, for example, load-bearing structural elements of retaining walls, excavation supports, embankment supports and others which are mainly horizontal and Bear moment loads, are statically loaded.

In this industry, the standard and most commonly used test method is testing soils by static horizontal load using a pile [1], where the load is applied to the pile head using standard hydraulic equipment. When investigating soils with a pile, the stress-strain condition of the pile-soil base system is examined using both conventional deflectometers and state-of-the-art transducers and equipment, which determines the bearing capacity of a pile for horizontal loading [2] and/or the proportionality factor (rigidity factor) of the substrate [3] can be determined using various methods.

Field methods for testing soils using moment load piles are completely absent from regulatory documents. However, there are reliable theoretical methods in regulation and reference sources [3-7], proposed and tested in the Soviet Union and further improved by modern scientists today [8-11], with the help of which the stress-strain state of the pile -Soil base system is determined when the pile is also subjected to a moment load.

As of today, regulatory documents of various countries and Ukraine [6] allow the use of numerous calculation methods for structures and facilities in their interaction with the ground base using powerful design software packages. However, the regulations show that to determine the stress-strain state, appropriate models of the soil base must be used, the parameters of which have yet to be determined using laboratory or field test methods to ensure the reliability of the calculations [12].

The method that comes closest to the proposed method by indirect properties is the method of static load testing of piles in subsidence soil [13], where there is no contact (interaction) between the top part of the piles and the soil base.

The task given is to determine the stress-strain condition of the pile-soil base system below the base level of the excavation when the pile bears the horizontal load H ₀ and the moment load M ₀ at the base level of the excavation.

$$\text{M}={\text{M}}_0-{\text{H}}_0\cdot {\text{I}}_0,$$

wobei H₀ die horizontale Bemessungslast auf dem Pfahl in der Basishöhe der Baugrube ist, kN;
M₀ ist die Bemessungsmomentlast auf dem Pfahl in der Basishöhe der Baugrube, kN.m;
I₀ ist der obere Teil der Gesamtlänge I des Pfahls von der Oberflächenhöhe bis zur Basishöhe der Baugrube, entlang der kein Kontakt mit der Bodenbasis besteht, m.The task is solved by first excavating the soil around the pile from the surface level to the base level of the excavation and excavating the soil with the pile from the surface level by applying the horizontal load H to the pile head in the direction of the load H ₀ and the moment load M be tested in the opposite direction of the load M ₀ , which are equal to: $$\text{H}={\text{H}}_0;$$

$$\text{M}={\text{M}}_0-{\text{H}}_0\cdot {\text{I}}_0,$$

where H ₀ is the horizontal design load on the pile at the base level of the excavation, kN;
M ₀ is the design moment load on the pile at the base level of the excavation, kN.m;
I ₀ is the upper part of the total length I of the pile from the surface level to the base level of the excavation along which there is no contact with the soil base, m.

1 shows a schematic diagram of the method for testing soils from surface level 1 by the experimental horizontal load H and moment load M using the pile 2 around which the soil 3 from surface level 1 to the base level of the excavation 4 was excavated prior to testing, about the stress-strain state of the pile-soil base system below the base of the excavation under the design horizontal load H ₀ and moment load M ₀ acting on the pile 2, which act according to directions 5 and 6, respectively, at the base level of the excavation 4 , to determine.

The essence of the test method is that by testing soils with a pile from the surface height through the experimental horizontal load H and the moment load M, the real interaction (test) of the pile-soil base system below the base of the excavation is simulated, under action the design horizontal load H ₀ acting on the pile and the design moment load M ₀ , which act on the base level of the excavation.

Applying the method of soil test from surface level with a pile transferring the design horizontal and moment loads at the base level of the excavation allows an assessment of the stress-strain Condition of the pile-soil base system used to justify and adjust the construction of retaining walls prior to digging an excavation.

CREDENTIALS

1. 1. DSTU B V.2.1-1-95. floors. field test procedure. Kiev: Ukrarkhbudinform 1997, p. 58 (in Ukrainian).
2. 2. DSTU B V.2.1-27:2010. piles. Determination of the load capacity of the results of field tests. Kyiv: Ministry of Regional Development and Construction of Ukraine, 2011, p. 11 (in Ukrainian).
3. 3. Guidelines for the design of bored pile support structures. Kiev: NIISK, 1985, p. 36 (in Russian).
4. 4. Guidelines for the design of pile foundations. NIIOSP named after NM Gersevanov, Gosstroy of the USSR. Moscow: Stroyizdat, 1980, p. 151 (in Russian).
5. 5. Pedestals, Foundations, and Underground Structures: The Designer's Reference Guide. Gorbunov-Posadov MI, Ilyichev VA, Krutov VI [et al.]; under the general editorship of Sorochan EA and Trofimenkov YG Moscow: Stroyizdat, 1985, p: 480 (in Russian).
6. 6. DBN V.2.1-10-2009 Revision 1. Bases and foundations of buildings. Main design rules. Kyiv: Ministry of Regional Development and Construction of Ukraine, 2011, p. 55 (in Ukrainian).
7. 7. DSTU-N B V.2.1-31:2014 Guidelines for the design of retaining walls. Kyiv:
   • Ministry of Regional Development of Ukraine, 2015, p. 86 (in Ukrainian).
8. 8th. Luchkovsky I.Ya. On the load-bearing capacity of flexible retaining walls. I.Ya. Luchkovsky, AV Samorodov, SV Yesakova. Municipal hospodarstvo mist. Kharkiv: OM Beketov National University of Urban Economy, 2012, Issue 105, pp. 62-68 (in Russian)
9. 9. Luchkovsky I.Ya., Yesakova SV The deformation methods for designing foundations. Kharkiv: Collegium, 2016. P. 196 (in Russian)
10. 10 Polyankin AG Studying the behavior of piles under horizontal and moment loads and improving the methods for designing the base of pile foundations: Summary of the dissertation for the Cand degree. the tech Sciences, AG Polyankin, Tyumen, 2014, p. 20 (in Russian)
11. 11. Gotman AL Research on the behavior of large bored piles under horizontal loads and their design. AL Gotman, AZ Gaysin. Bulletin of the Perm National Polytechnic Research University. construction and architecture. Perm: Perm National Research Polytechnic University. Issue 9, No. 3, 2018, pp. 14-27 (in Russian)
12. 12. Skochko LO Interactions between the multi-level retaining structures and the soil mass: summary of the dissertation for the degree Cand. the tech sciences. LO Skochko. Kyiv, 2018, p. 24 (in Ukrainian)
13. 13. Inventor's certificate SU 401409730, E 02 D 33/00. Procedure for the static analysis of piles in settlement soil. Reinforced concrete design bureau named after AA Yakushev and the State Institute of Urban Design (I.G. Ladyzhensky, V.S. Saburov). published July 15, 988, Bull. No. 26.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Non-patent Literature Cited

• DSTU B V.2.1-1-95. floors. field test procedure. Kiev: Ukrarkhbudinform 1997, p. 58 [0010]
• DSTU B V.2.1-27:2010. piles. Determination of the load capacity of the results of field tests. Kyiv: Ministry of Regional Development and Construction of Ukraine, 2011, p. 11 [0010]
• Guidelines for the design of bored pile support structures. Kiev: NIISK, 1985, p. 36 [0010]
• Guidelines for the design of pile foundations. NIIOSP named after N. M. Gersevanov, Gosstroy of the USSR. Moscow: Stroyizdat, 1980, p. 151 [0010]
• Pedestals, Foundations, and Underground Structures: The Designer's Reference Guide. Gorbunov-Posadov M.I., Ilyichev VA, Krutov V.I. [et al.]; under the general editorship of Sorochan E.A. and Trofimenkov Y.G. Moscow: Stroyizdat, 1985, p: 480 [0010]
• DBN V.2.1-10-2009 Revision 1. Bases and foundations of buildings. Main design rules. Kyiv: Ministry of Regional Development and Construction of Ukraine, 2011, p. 55 [0010]
• Luchkovsky I.Ya. On the load-bearing capacity of flexible retaining walls. I.Ya. Luchkovsky, A.V. Samorodov, S.V. Yesakova. Municipal hospodarstvo mist. Kharkiv: O.M. Beketov National University of Urban Economy, 2012, Issue 105, pp. 62-68 [0010]
• Luchkovsky I.Ya., Yesakova S.V. The deformation methods for the design of foundations. Kharkiv: Collegium, 2016. p. 196 [0010]
• Polyankin A.G. Studying the behavior of piles under horizontal and moment loads and improving the methods of designing the base of pile foundations: summary of the doctoral thesis for the Cand degree. the tech Sciences, A.G. Polyankin, Tyumen, 2014, p. 20 [0010]
• Gotman A.L. Research on the behavior of large bored piles under horizontal loads and their design. A.L. Gotman, A.Z. gaysin. Bulletin of the Perm National Polytechnic Research University. construction and architecture. Perm: Perm National Research Polytechnic University. Issue 9, No. 3, 2018, pp. 14-27 [0010]
• Skochko L.O. Interactions between the tiered retaining structures and the soil mass: summary of the dissertation for the degree Cand. the tech sciences. LO Skochko. Kiev, 2018, p. 24 [0010]

Claims (1)

Method of testing soils using a pile with a total length of I from the surface level, which transmits the horizontal design load H ₀ and the design moment load M ₀ to the soil base at the base level of the excavation to determine the stress-strain condition of the pile-soil base -System below the base level of the excavation to determine the pile-soil base system, which is characterized in that soil around the pile is first excavated from the surface level to the base level of the excavation, and the test is carried out from the surface level by the horizontal load H is applied to the pile head in the direction of the load H ₀ and the moment load M in the opposite direction of the load M ₀ , which is equal to: $$\text{H}={\text{H}}_0;$$

$$\text{M}={\text{M}}_0-{\text{H}}_0\cdot {\text{I}}_0,$$

where H ₀ is the horizontal design load on the pile at the base level of the excavation, kN; M ₀ is the design moment load of the pile at the base height of the excavation, kN.m; I ₀ is the upper part of the total length I of the pile from the surface level to the base level of the excavation along which there is no contact with the soil base, m.

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