Source: https://www.eurocode.us/structural-design-eurocode-7/
Timestamp: 2018-12-13 01:58:12
Document Index: 620707166

Matched Legal Cases: ['art 1', 'arts 1', 'art 1', 'art 1', 'art 1', 'art 2', 'art 3', 'art 2', 'art 2', 'art 2']

Serviceability limit states are defined as States that correspond to conditions beyond which specified service requirements for a structure or structural member are no longer met Verification of serviceability involves checking that design effects of actions (e.g. settlements) do not exceed their corresponding design limiting values (i.e. limiting settlements). Verification of serviceability is expressed in Eurocode 7 by the inequality Ed < Cd EN 1990 exp (6.13) & EN 1997-1 exp (2.10) in...
Contents of the Eurocode
Eurocode - Basis of structural design2 is divided into six sections and four annexes (A-D), as shown in Figure 2.1. In this diagram, the size of each segment of the pie is proportional to the number of paragraphs in the relevant section. Figure 2.1. Contents of the Eurocode Figure 2.1. Contents of the Eurocode EN 1990 describes the basis for the design and verification of buildings and civil engineering works, including geotechnical aspects, and gives guidance for assessing their structural...
Fri, 07 Jul 2017 | Structural Design | 1 comment
Design by calculation involves the use of equations that relate soil and rock parameters to shaft friction and end bearing. Unfortunately, available calculation models do not reliably predict the ultimate capacity of piles, owing to the complex interaction between pile type, construction processes, workmanship, and group effects. Consequently, relatively large factors of safety (in the range 2.0-3.0) are applied in such calculations. The partial factors given in Eurocode 7 for pile resistance...
Design by testing involves using the results of static load, dynamic impact, or ground tests to define the total pile resistance. This approach can only work where trial piles are installed and the results of tests on these piles are used to design the working piles. Traditionally, on smaller contracts, pile testing is avoided by using a large factor of safety on the calculated capacity. Although EN 1997-1 emphasizes design by static load testing, for most contracts this is generally...
Design situations and limit states
9 of Eurocode 7 Part 1 includes a series of illustrations showing limit modes for gravity walls, including overall stability, foundation failure, and structural failure. Figure 11.2 gives examples of ultimate limit states that can affect mass gravity walls. From left to right, these include toppling, sliding, and bearing failure. Figure 11.2. Examples of ultimate limit states for mass gravity walls Figure 11.2. Examples of ultimate limit states for mass gravity walls fi.e. weaker strata are...
Rd And Ed In Structural Calculation
Figure 13.6 shows a single pile subject to an imposed vertical action T, which attempts to pull the pile out of the ground. The uplift force is countered somewhat by the pile's self-weight W and the total vertical tensile action that results is Ft. The characteristic value of Ft is given by permanent and variable components of T, respectively the symbol WGk represents the pile's characteristic self-weight (a favourable permanent action) and is the combination factor applicable to the ith...
In structural engineering, effects of actions are a function of the actions applied to a structure and that structure's dimensions, but not of material strength, i.e. where the notation E denotes that the design effect Ed depends solely on design actions Fdi and design dimensions adj. This holds true for linear elastic analysis of structures, but not for plastic analysis. An example may help to illustrate the ideas behind this equation. Figure 2.13 shows a simply-supported concrete beam subject...
Geotechnical investigation and testing reports Drilling and sampling reports
Sampling methods and groundwater measurements are covered by EN ISO 22475, details of which are given in Chapter 4. EN ISO 22475-1 sets out the requirements for reporting the results of drilling, sampling, and groundwater measurements. Figure 16.2 summarizes the common features of these reports. Figure 16.2. Contents of a drilling and sampling report Figure 16.2. Contents of a drilling and sampling report These reports are similar to those defined in Section 7 of BS 59302 and represent typical...
'Effects of actions' (or 'action effects') is a general term denoting internal forces, moments, stresses, and strains in structural members plus the deflection and rotation of the whole structure. en 1990 1.5.3.2 For most structural designs, verification of limit state STR involves action effects that are independent of the strength of the structural materials (see Chapter 2). However, in many geotechnical designs, verification of the STR and GEO limit states involves effects of actions that...
Difference Moderately Conservative And Characteristic Values
Values that are 'very unlikely to be exceeded' (but not worst physically possible) Safety factors applied to soil strength 1.0 (temporary works) 1.2 (permanent works) According to CIRIA 104's successor, CIRIA C580,15 soil parameters selected by this method are equivalent to representative values defined in BS 8002 (see Section 5.3.3) and to characteristic values defined in Eurocode 7 (Section 5.3.2). The difference between CIRIA 104's moderately conservative value and Eurocode 7's cautious...
International Standardization Organization ISO
The International Organization for Standardization (known as ISO, after the Greek word 'isos' meaning 'equal') was founded in 1947 to 'facilitate the international coordination and unification of industrial standards'.13 ISO is a network of national standards bodies from 158 countries (comprising 103 member bodies, 46 correspondent members, and 9 subscriber members). Figure 1.5 illustrates the current membership of ISO. Based in Geneva, ISO has almost 200 technical committees (TCs) which are...
Links between the Eurocodes
Figure 1.2 and Plate 3 (in the colour section) show the connections between the main parts of the Structural Eurocodes (in the style of the London Underground tube map). Only the main parts (not the sub-parts) of the Eurocodes are shown. Along the 'Central Line' (in red on Plate 3) are the ten parts (Parts 1) giving general rules and rules for buildings. For example, EN 1992-1 provides general rules for concrete structures. Around the 'Circle Line' (in yellow on Plate 3) are the six parts...
L. (2005) 'Evaluation of uplift and heave designs to Eurocode 7', Proc. Int. Workshop on the Evaluation of Eurocode 7, Trinity College, Dublin, pp. 147-158. 2. NA to BS EN 1997-1 2004, UK National Annex to Eurocode 7 Geotechnical design - Part 1 General rules, British Standards Institution. 3. Terzaghi, K. (1936) 'The shearing resistance of saturated soils', 1st Int. Conf. on Soil Mechanics, 1, pp. 54-56. 4. Terzaghi, K., and Peck, R. B. (1967) Soil mechanics in engineering...
Statistical methods for ground characterization
' Use of statistics demands a high order of statistical technique, available from very few designers who have committed their time to training and experience in geotechnical engineering.'24 The characteristic value of a material property Xk is defined in Chapter 2 as follows where mX is the mean of X, sX its standard deviation, and kn a statistical coefficient that depends on the number of samples n. This definition may be stated more simply as Characteristic value mean value + epistemic x...
The design of embedded walls to Eurocode 7 involves checking that the wall has sufficient embedment to prevent the wall rotating about a fixed point (for example, a point of fixity below formation or a single row of anchors), sufficient strength to mobilize resistance over the full length of the wall, and sufficient stiffness to keep wall displacements and settlement behind the wall within acceptable limits. The design must also demonstrate that the wall has sufficient bearing resistance to...
Verification of strength
'It is not possible to fight beyond your strength, even if you strive' - Homer (800-700 BC)1 Verification of strength to Eurocode 7 involves checking that design effects of actions do not exceed their corresponding design resistances. Verification of strength is expressed in Eurocode 7 by the inequality Ed < Rd EN 1990 exp (6.8) & EN 1997-1 exp (2.5) in which Ed the design effects of actions and Rd the corresponding design resistance. This requirement applies to ultimate limit state GEO,...
The worked examples in this chapter illustrate the way in which statistics may be used to determine the characteristic values of various geotechnical parameters the standard penetration blow count in Thames Gravel (Example 5.1) the undrained strength of London Clay (Example 5.2) and the angle of shearing resistance of Leighton Buzzard Sand (Example 5.3). Specific parts of the calculations are marked O, , , etc., where the numbers refer to the notes that accompany each example. 5.7.1 Standard...
Sun, 18 Jun 2017 | Structural Design
Figure 11.6 shows the pressures that act on a T-shaped gravity wall, assuming that a surcharge q exists at ground surface and the water table is located above formation level. The assumption is made that the wall's heel is wide enough for a Rankine zone to form within the backfill that sits on top of the wall's heel (see Section 11.4.4 for further discussion of this point). Figure 11.6 shows the pressures that act on a T-shaped gravity wall, assuming that a surcharge q exists at ground surface...
Wed, 16 Dec 2015 | Structural Design
EN 1997-1 Annex C provides a numerical procedure for determining active and passive earth pressure coefficients for use in retaining wall design, which is discussed in Chapter 12. The charts that follow show the variation in KaY and KpY (denoted Ka and Kp on these charts) with angle of shearing resistance 9, for different values of interface friction 5 (0 , 5 , 10 , 15 , 20 , 25 , and 30 ), for vertical walls (0 0 ). Each figure gives curves for different slope gradients tan p (flat, 1 10, 1 5,...
Verification by the partial factor method Partial factors on actions
Thu, 08 Oct 2015 | Structural Design
Representative actions (Frep) are converted into design values (Fd) by multiplying by an appropriate partial factor (yf) where yf takes account of uncertainties in the magnitude of the action, model uncertainties, and dimensional variations. For unfavourable actions, yf 1, whereas for favourable actions yf 1 and the previous equation is qualified as follows (see Figure 2.18) Values of yf and YF,fav for persistent and transient design situations are given in EN 1990 and vary between 0.9 and 1.5,...
Thu, 16 Feb 2012 | Structural Design
The requirement for a Ground Investigation Report GIR appears in EN 1997-2 The results of a geotechnical investigation shall be compiled in a Ground Investigation Report which shall form part of the Geotechnical Design Report. EN 1997-2 6.1 1 P The contents of the GIR are specified both in EN 1997-1 as an Application Rule and in EN 1997-2 as a Principle The Ground Investigation Report should normally consist of shall consist of, if appropriate a presentation of all available geotechnical...
Sat, 24 Sep 2011 | Structural Design | 2 comments
Limiting equilibrium methods are commonly used to assess the required penetration of embedded retaining walls, associated shear forces and bending moments in their cross-sections, and the forces in any props or anchors used to support them. Limiting equilibrium methods assume that the full strength of the ground is mobilized uniformly around the wall, so that the wall is at the point of collapse or 'limiting equilibrium' . Cantilever walls and walls propped near their top are statically...
Tue, 13 Sep 2011 | Structural Design
Design values of earth pressures for the verification of serviceability limit states must be derived using characteristic soil parameters, taking account of the initial stress, stiffness, and strength of the ground the stiffness of structural elements and the allowable deformation of the structure. These earth pressures may not reach limiting i.e. fully active or passive values. EN 1997-1 9.8.1 2 P, 4 , and 5 Calculations of wall movement are not necessarily required to verify the avoidance of...
TChoice made in Eurocode 7 Designers' Guide3 It is unclear whether this should be Yes or No tChoice made in Eurocode 7 Designers' Guide3 It is unclear whether this should be Yes or No 6.3.4 Choice of design approach by different European countries Eurocode 7 Part 1 allows each country to specify in its National Annex which design approach must be used within its jurisdiction. The choices made by the countries within CEN4 are summarized in Figure 6.18 for slopes and Figure 6.19 for other...
The Structural Eurocodes are a suite of ten standards for the design of buildings and civil engineering works, as illustrated in Figure 1.1 and Plate 2 in the book's colour section . These standards are divided into fifty-eight parts and are accompanied by National Annexes issued by the various European countries that have introduced the Eurocodes into their design practice. Figure 1.1. Standards within the Structural Eurocodes programme. See Plate 2 for colour version. Figure 1.1. Standards...
Comparison with existing practice
Tue, 30 Aug 2011 | Structural Design
The following sub-sections compare the Ground Investigation and Geotechnical Design Reports with traditional reports on these subjects. Current UK practice is specified in Section 7 of BS 5930,5 which defines the series of reports illustrated in Figure 16.7. Field reports cover all the information that needs to be obtained while working on site, e.g. the recording of in situ tests such as the standard penetration test, cone penetration test, pressuremeter, etc. and production of drillers' logs....
Sun, 28 Aug 2011 | Structural Design
Curve 1 on each graph shows the results obtained for a serviceability limit state calculation, with all partial factors set to 1.0 - i.e. with all parameters at their characteristic values. The depths of embedment needed to ensure stability for this situation are 9.63m and 7.00m respectively for the two walls. Curve 2 shows the results obtained when passive earth pressures are treated as an unfavourable action, as allowed by the Single-Source Principle discussed in Chapter 3. A single partial...
Reaction to the Eurocodes
Wed, 24 Aug 2011 | Structural Design
Unfortunately, many engineers' initial reaction to Eurocode 7 is a cross between The Eurocode Scream see Figure 17.1 and the natural instinct of an ostrich, which , when frightened, buries its head in the sand. However, when the shock of the new is overcome, views change as the benefits of the Eurocodes become apparent. The views of many engineers are based on limited knowledge of the Eurocodes and even less experience of using them in practice. Figure 17.2 summarizes some of the opinions that...
Mon, 08 Aug 2011 | Structural Design
'In dealing with real world problems, uncertainties are unavoidable'1 5.1 From test results to design Ground characterization is the process of deducing suitable values for geotechnical parameters from the results of field or laboratory tests. Ultimately, these values will be used in design calculations, after the application of appropriate partial factors to cater for uncertainties in the available data. There are three distinct steps in this process, as shown in Figure 5.1. Put simply,...
Mon, 25 Jul 2011 | Structural Design | 3 comments
The worked examples in this chapter consider the design of a T-shaped gravity wall retaining dry fill under undrained conditions Example 11.1 the same wall under drained conditions Example 11.2 the same wall again, retaining wet fill under drained conditions Example 11.3 and a mass concrete wall retaining granular fill Example 11.4 . Specific parts of the calculations are marked O, , , etc., where the numbers refer to the notes that accompany each example. 11.11.1 T-shaped gravity wall...
Thu, 21 Jul 2011 | Structural Design
Eurocode 7 notes that, for anchored or strutted flexible walls, the magnitude and distribution of earth pressures, internal structural forces, and bending moments depend to a great extent on the stiffness of the structure, the stiffness and strength of the ground, and the state of stress in the ground. If structural stiffness is significant, soil-structure interaction analysis should be performed to determine the distribution of actions. The stress-strain relationships used in such analyses...
Fri, 15 Jul 2011 | Structural Design | 2 comments
A number of organizations are likely to be involved in the preparation of geotechnical reports design consultant structural or geotechnical site investigation contractor design-and-build contractor. Although this list may not include all parties that might be involved in a construction project, we will use it to illustrate the potential changes that Eurocode 7 will have on the production of geotechnical reports. The client is unlikely to be involved in the preparation of either the Ground...
QEk A A
Fri, 08 Jul 2011 | Structural Design | 1 comment
Where Vrep is a representative vertical action VGk, VQk, and WGk are as defined above A' is the footing's effective area defined in Section 10.4.2 and is the combination factor applicable to the ith variable action see Chapter 2 . If we assume that only one variable action is applied to the footing, this equation simplifies to since 1.0 for the leading variable action i 1 . The design bearing pressure qEd beneath the footing is then where yg and yq are partial factors on permanent and variable...
Fri, 08 Jul 2011 | Structural Design
The worked examples in this chapter consider the design of a pad footing on dry sand Example 10.1 the same footing but eccentrically loaded Example 10.2 a strip footing on clay Example 10.3 and, for the same footing, verification of the serviceability limit state Example 10.4 . Specific parts of the calculations are marked O, , , etc., where the numbers refer to the notes that accompany each example. Example 10.1 considers the design of a simple rectangular spread footing on dry sand, as shown...
Identification and classification of soil
Thu, 07 Jul 2011 | Structural Design
Identification and classification of soil is covered by International Standard EN ISO 14688, which is divided into three parts covering description Part 1 , classification Part 2 , and data transfer Part 3 .6 EN ISO 14688 is referenced extensively in EN 1997-2. Figure 4.6 illustrates the logic for identifying soils according to EN ISO 14688-1. The main soil types are divided into made ground, organic soil, volcanic soil, and very coarse, coarse, and fine soils. Very coarse soils are sub-divided...
Mon, 04 Jul 2011 | Structural Design
The Structural Eurocodes are based on limit state principles, in which a distinction is made between ultimate and serviceability limit states. Ultimate limit states are concerned with the safety of people and the structure. Examples of ultimate limit states include loss of equilibrium, excessive deformation, rupture, loss of stability, transformation of the structure into a mechanism, and fatigue. Serviceability limit states are concerned with the functioning of the structure under normal use,...
UkM rw h d yw d j
Thu, 30 Jun 2011 | Structural Design | 1 comment
D,dst Yg,dstYw y dj Yg,dstYw 1 d and, since this is a permanent destabilizing action, its design value is The characteristic vertical total stress acting on the same plane is and, since this is a permanent stabilizing action, its design value is Substituting these expressions into ud dst lt od stb and simplifying produces -1 hnL _ I j 0.33 - hnL 1.5 I 3 I 3.0 1. For this situation, we conclude that the partial factors specified for limit state HYD are equivalent to a global factor of 3.0 on the...
Wed, 29 Jun 2011 | Structural Design
The design is unacceptable if the degree of utilization is gt 100 Traditional factor of safety against piping The soil's critical hydraulic gradient is i crit - 1 Factor of safety on hydraulic gradient is F - 3.38 w 0 The degree of utilization using expression 2.9 a is close to 100 , whereas using 2.9 b it is less than 50 . Eurocode 7 does not explicitly state where the partial factors should be applied, which leads to the discrepancy between these expressions, which was not anticipated by the...
Wed, 29 Jun 2011 | Structural Design | 1 comment
Eurocode 7 discusses three types of anchorage test investigation, suitability, and acceptance. An investigation test is a 'load test to establish the ultimate resistance of an anchor at the grout ground interface and to determine the characteristics of the anchorage in the working load range'. This definition is identical to the one given in EN 1537. EN 1997-1 8.1.2.5 Investigation tests are performed, before working anchorages are installed, to establish the anchorage's ultimate pull-out...
Material properties and resistance Resistance
Fri, 24 Jun 2011 | Structural Design
The resistance of a structural member is defined as the capacity of a member or component, or cross-section of a member or component of a structure, to withstand actions without mechanical failure In structural engineering, resistance is a function of the structure's material strengths and its dimensions, but not of the magnitude of any actions applied to the structure, i.e. where the notation R denotes that the design resistance Rd depends solely on design material strengths Xdi and design...
Limit state EQU
Fri, 24 Jun 2011 | Structural Design | 1 comment
Limit state EQU, dealing with static equilibrium, is defined as Loss of static equilibrium of the structure considered as a rigid body, where minor variations in the actions or their distribution are significant, and the strengths of materials are generally not governing. Limit state EQU does not occur when the destabilizing design effects of actions Ed,dst are less than or equal to the stabilizing design effects Ed,stb Ed, dst Ed,stb EN 1990 x 67 Ed, dst Ed,stb EN 1990 x 67 Figure 2.6....
Deriving geotechnical parameters Overview
Tue, 21 Jun 2011 | Structural Design
The derived value of a geotechnical parameter is defined in Eurocode 7 as the value obtained by theory, correlation or empiricism from test results EN 1997-1 1.5.2.5 amp EN 1997-2 1.6 3 As the flow-chart of Figure 5.2 illustrates, test results may be converted into derived values X by use of correlations such as that between cone penetration resistance and angle of shearing resistance in sand , theoretical considerations such as conversion of triaxial compression into plane strain strengths for...
Sat, 18 Jun 2011 | Structural Design
Eurocode 7 - Geotechnical design, Part 2 - ground investigation and testing2 is divided into six sections and twenty-four annexes, as illustrated in Figure 4.1 and Plate 6 in the book's colour section . 2 Planning of ground 1 General Investigations 3 Soil and rock Figure 4.1. Contents of Eurocode 7 Part 2. See Plate 6 for a colour version. 2 Planning of ground 1 General Investigations 3 Soil and rock Figure 4.1. Contents of Eurocode 7 Part 2. See Plate 6 for a colour version. EN 1997-2 provides...
Supervision monitoring and maintenance
Mon, 04 Apr 2011 | Structural Design
Eurocode 7 has specific requirements to ensure the quality and safety of a structure the construction processes and workmanship shall be supervised the performance of the structure shall be monitored during and after construction and the structure shall be adequately maintained. EN 1997-1 qualifies this requirement by saying these tasks should be undertaken 'as appropriate'. Thus, if construction does not need supervising, or the structure does not need monitoring or maintaining, then the...
Actions and design situations Design situations
Actions combinations and effects
Basis of design - 2 3
Case studies selecting characteristic values
Changes made in the UK National Annex
Construction Products Directive CE
Design of anchorages
Design of embedded walls
Design of slopes and embankments
Design situations and limit states - 2 3 4
E EKllG sin
E Q sin a
Emirates Stadium Pile Tests
Execution of geotechnical works
Footings subject to horizontal actions
Footings subject to vertical actions
Ground investigation for anchorages
Ground investigation for embedded walls
Ground investigation for gravity walls
Identification and classification of rock
Info Qur 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128
Info Vrn 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
Introducing reliability into the design
L - 2 3 4 5 6
Limit state STR
Medium dense gravelly SAND grSa
N i N - 2 3
National standards bodies NSBs
Notes and references - 2 3 4 5 6 7
Notes on the worked examples
Obtaining the characteristic value
Plate Summary of ground characterization
Principles and Application Rules
Pv psinesh
R - 2 3 4 5
Reinforced fill structures
Role of Eurocode in UK practice
Scope of Eurocode Part
Simplified verification of serviceability
Slope stability design charts
Stability of an infinitely long slope
Structural analysis and design by testing
Structural design - 2
Summary of key points - 2 3 4 5 6 7 8 9 10 11
Supervision monitoring and maintenance - 2
Walls and steep slopes
Worked examples - 2 3
Zi mz - 2 3
YBNY qult cN qN
Za d and za m
Za t m
Retaining Wall Design Example Eurocode