geo5岩土工程设计手册2.pdf

E n g i n e e r i n g ma n u a l s P a r t 2 Engineering manuals for GEO5 programs Part 2 Chapter 1 - 12, refer to Engineering Manual Part 1 Chapter 13. Pile Foundations – Introduction . 2 Chapter 14. Analysis of vertical load-bearing capacity of a single pile 9 Chapter 15. Analysis of a single pile settlement . 21 Chapter 16. Analysis of vertical load-bearing capacity and settlement of piles investigated on the basis of CPT tests . 31 Chapter 17. Analysis of horizontal bearing capacity of a single pile 40 Chapter 18. Analysis of vertical load bearing capacity and settlement of a pile group 48 Chapter 19. Analysis of deformation and pile group dimensioning . 58 Engineering manuals for GEO5 programs - Part 2 www.finesoftware.eu 2 Chapter 13. Pile Foundations – Introduction The objective of this chapter is to explain the practical use of programs for the analysis of pile foundations in GEO 5. GEO 5 software contains three pile foundation analysis programs – Piles, Pile CPT and Pile Group. The text below contains closer explanation of which of the programs is to be used under particular conditions – individual programs are subsequently described in other chapters. Vertical load-bearing capacity of pile foundations is determined by various methods:  by a static pile test: these tests are directly required in some countries and a structural analysis functions only as a preliminary pile foundation proposal;  by an analysis based on soil shear strength parameters: using analysis methods NAVFAC DM 7.2, Tomlinson, CSN 73 1002 and Effective stress in programs PILES and PILE GROUP;  by an analysis based on the assessment of penetration tests: PILE CPT program;  by an analysis according to equations for regression curves obtained from the results of static loading tests (according to Masopust): PILES program; Vertical load-bearing capacity is determined from the pile loading curve for corresponding (allowable) settlement (CSN 73 1002 standard specifies the corresponding settlement value mms0 .25 lim ).  by an analysis based on Mohr-Coulomb parameters and stress-strain properties of soils: using the so-called Spring Method in PILES and PILE GROUP programs;  by numerical analysis using the Finite Element Method: the FEM program. It follows from this list that piles can be assessed using many ways and on the basis of different input parameters. It means that analysis results can be identical, but often they can significantly differ. Engineering manuals for GEO5 programs - Part 2 www.finesoftware.eu 3 The great advantage of GEO 5 is the fact that the user can try more variants and analysis methods, find the most likely behaviour of the pile foundation and subsequently determine the total bearing capacity or settlement of a single pile or a pile group. The vertical load-bearing capacity of pile foundations is assessed in GEO 5 programs (with the only exception: Pile Group – Spring Method) only for the loading by a vertical normal force. The loading by horizontal forces, bending and torsional moments has no influence on the analysis of the vertical load-bearing capacity of piles. The procedure of the vertical load-bearing capacity of a single pile analysis in GEO 5 – PILES is presented in Chapters 14 and 3, whilst the analysis for the same pile on the basis of CPT tests is described in Chapter 16. Horizontal bearing capacity of pile foundations: The result of the analysis for a horizontally loaded pile is the pile horizontal deformation and the curve for internal forces along the pile shaft. In the case of a single pile, its horizontal deformation and reinforcement depend on the calculated modulus of horizontal reaction of the sub-soil and the loading by the lateral force or the bending moment. The analysis procedure is explained in Chapter 17. The analysis for a pile group is presented in Chapter 19. Settlement of pile foundations: The actual load-bearing capacity of a pile is directly associated with its settlement because of the fact that virtually any pile settles under the action of loading and gets vertically deformed. The settlement of single piles is determined in the PILES program by the following methods:  according to Masopust (non-linear): the program analyses the settlement of a single pile on the basis of the regression coefficients along the skin and under the pile base.  according to Poulos (linear): the program analyses the value of the total settlement on the basis of the determined pile base bearing capacity b R and the pile skin bearing capacity s R. Engineering manuals for GEO5 programs - Part 2 www.finesoftware.eu 4  by means of the Spring Method: the program analyses the loading curve on the basis of set parameters of soils using the Finite Element Method. The PILES program constructs the loading curve (the so-called working diagram) for all of the methods. The settlement of a pile group is described in Chapter 18。