BS 6031-2009 pdf free download

BS 6031-2009 pdf free download.Code of practice for earthworks.
The grouping of soils by particle size for testing purposes [see Table 1b) is significantly different to that used for soil particle size classification [see Table la)]. 85 1377-1 divides soil groups based on the soil sizes that are suitable for different forms of test.
Most soils consist of a principal and secondary fractions and are defined as “composite soil”, the identification of which is described at BS EN ISO 14688-1:2002, 4.3. A composite fine soil is one where the fines fraction determines the engineering properties of the soil (this can include relatively coarse soil where the fine matrix is sufficient to result in the soil being matrix dominated); where the fines fraction is insufficient to determine the engineering properties the soil is a composite coarse soil. To fully classify the soil consideration is given to other factors including plasticity of the fines fraction (test carried out on <425 pm material). However, the principles for classification of soils set out at BS EN ISO 14688-2:2004 is useful in assessing likely earthworks behaviour.
In the field of earthworks the assessment of whether the fines fraction (i.e. passing a 63 pm sieve) is sufficient to determine the engineering properties of the soil will differ between two major cases:
• where a soil is considered as an engineered fill, where all fills with> 15% fines are classified as cohesive; and
• soil assessed for geotechnical design (e.g. slope stability, settlement or bearing capacity) where generally fine (cohesive) soils are likely to include> 35% fines.
Therefore, in accordance with industry practice, the soils described in this standard as “coarse/granular”, “intermediate” or “fine/cohesive” contain different percentages of fines depending on the context in which the descriptions are used [see Table lc)J. Table ic) also provides a simplified summary of the BS EN ISO 14688-1:2002 approach to illustrate that both approaches fit within that framework.
In composite soils the assessment of the “dominant soil fraction” which will determine the engineering properties of the soil requires consideration of a variety of soil characteristics (particularly plasticity grading and soil fabric). Within the intermediate zones illustrated in Table ic) experience shows that seemingly similar soils can behave differently with relatively small differences in these soil characteristics. These variations are very notable in glacial till as described in CIRIA
C504 [81.
Note that Table la) and Table 1 b) are presented based on particle sizes, while Table ic) shows percentage passing the 63 pm sieve.BS 6031-2009 pdf free download.