The formation of a pile in the existing foundation and soil creates a new foundation construction which has a structure of foundation-pile-soil. This construction must be able to transfer loads from the foundation to the pile and from the pile to the soil.
The pile structure has to transfer an imposed load. From the point of view of continuum mechanics determination of the capacity of such a system is preceded by the analysis of contact problem of three contact surfaces. Each of these surfaces is determined by different pairs of materials. The pair which creates a pile anchorage is a material from which the foundation is built (structure of stone and grout, brick and grout, concrete or reinforced concrete and grout. The pile structure is formed by grout and steel rebar. The pile formed in soil is created by a pair of grout and soil. What is important is that on contact surfaces the materials adhering to one another are subjected to different deformation types that are controlled by mechanical properties and geometry of these surfaces.
In the paper, additional conditions that should be fulfilled for the foundation-pile-soil system to make load transfer from foundation to soil possible and safe are presented. The results of research done by the author on foundation-pile contact surface are discussed. The tests were targeted at verifying the bearing capacity of anchorage and deformation of piles made of grout and other materials from which foundations are built. The specimens were tested in tension and compression. The experiments were conducted on the amount specimens which is regarded as small sample to enable the statistical analysis of the results.
 PN-EN 1997-1:2008, Eurocode 7 Geotechnical Design, PKN, Warszawa, Poland.
 PACHLA H., Kotwienie pali iniekcyjnych w betonowych fundamentach, Geoinżynieria drogi mosty tunele, 2011, 31(2), 40-43.
 PACHLA H., Kotwienie niskociśnieniowych pali iniekcyjnych wciskanych w grunt w wykonanych z cegły, Geoinżynieria drogi mosty tunele, 2014, 46(1), 52-54.
 PACHLA H., Deformacja i nośność zakotwienia niskociśnieniowych pali iniekcyjnych w betonowym fundamencie przy obciążeniu wciskającym pal w grunt, Geoinżynieria drogi mosty tunele, 2014, 47(2), 28-32.
 PACHLA H., Zakotwienie wyciąganych z fundamentu niskociśnieniowych pali iniekcyjnych, Geoinżynieria drogi mosty tunele, 2014, 48(3), 48-52.
 HODUREK C., SZYPROWSKI A., Projekt konstrukcyjny wykonawczy: Rozbudowa sklepu IKEA w Krakowie, 2009.
 GWIZDAŁA K., Fundamenty palowe: tom 1, Technologia i obliczenia, Wydawnictwo Naukowe PWN, Warszawa, 2010.
 CHOI CH., CHO SAM-DEOK, Field verification study for micropile load capacity, 10th International Workshop on Micropiles, Washington D.C., United States, 2010.
 WILDER D., CADDEN A., TRAYLOR R., Comprehensive Load Transferring Micropiles Through Concrete Footings: A Full Scale Test Program, ADSC The International Association of Foundation Drilling, Dallas, 2005.
 SCARBOROUGH J.A., NEWMAN F.B., Compressive Strength Testing of Micropile Grout, ADSC The International Association of Foundation Drilling, Dallas, 2004.
 BRUCE D.A., JURAN I., Drilled and Grouted Micropiles: State-of-Practice Review, ADSC The International Association of Foundation Drilling, Dallas, 1997.
 WEINSTEN G.N., Long-Term Behavior of Micropiles Subject to Cyclic Axial Loading, ADSC The International Association of Foundation Drilling, Dallas, 2008.
 ARMOUR T.A., GRONECK P., KEELEY J.N., Micropile Design and Construction Guidelines Implementation Manual, ADSC The International Association of Foundation Drilling, Dallas, 2000.
 SABATINI P.J., TANYU B., ARMOUR T.A., Micropile Design and Construction Guidelines Reference Manual, ADSC The International Association of Foundation Drilling, Dallas, 2005.
 BRUCE D., RICHARDS JR. T. D., ARMOUR T., Micropile Guide Specification, ADSC The International Association of Foundation Drilling, Dallas, 2003.
 RODRIGUEZ-MAREK A., MUHUNTHAN B., Seismic Behavior of Micropiles, ADSC The International Association of Foundation Drilling, Dallas, 2005.
 MASSOUDI N., Some Observations on Micropile Inspection and Testing, ADSC The International Association of Foundation Drilling, Dallas, 2005.
 CADDEN A.W., BRUCE D.A., BEAN J.J., The Field Inspection and Documentation of Micropile Works, ADSC The International Association of Foundation Drilling, Dallas, 2005.
 SHEFFFIELD P., LI XIAN-XING, RAMIREZ D., Micropile bearing plates: are they necessary? 7th International Workshop on Micropiles, Schrobenhausen, Germany, May 3-7.
 VELUDO J., JÚLIO E.N.B.S., PINTO P.L, Bond strength of micropile (grout) concrete interfaces in RC footings strengthened with micropiles, 9th International Workshop on Micropiles, London, United Kingdom, May 10-13.
 MARQUES D., VELUDO J., SANTOS P., The influence of hole surface treatment and confinement level in the connection capacity between RC footings and strengthening micropiles, International Workshop on Micropiles.
 VELUDO J., JÚLIO E.N.B.S., DIAS-DA-COSTA D., Compressive strength of micropile-to-grout connections, Construction and Building Materials, 2012, 26, 172-179.
 VELUDO J., DIAS-DA-COSTA D., JÚLIO E.N.B.S., PINTO P.L., Bond strength of textured micropiles grouted to concrete footings, Engineering Structures, 2012, 35, 288-295.
 GÓMEZ J., CADDEN A.W., TRAYLOR R.P., BRUCE D.A., Connection capacity between micropiles and existing footingsbond strength to concrete, [in:] D.A. Bruce, A.W. Cadden (eds.), Geo3 GEO Construction Quality Assurance/Quality Control Conference Proceedings, TX: Dallas/Ft. Worth, 2005, 196-216.