Robertson et al (1986) and Robertson (1990) stressed that the CPT-based charts were predictive of Soil Behavior Type (SBT), since the cone responds to the in-situ mechani-cal behavior of the soil and not directly to soil classification criteria based on grain-size distribution and soil plasticity (e.g. Unified Soil Classification System, USCS).

The most used CPT soil behavior type (SBT) chart was suggested by Robertson et al. (1986), and the updated, dimensionless version (Robertson, 2010) is shown in Figure 22. This chart uses the basic CPT parameters of cone resistance, q t and friction ratio, R f = (f s /q t)100%. The chart is global in nature and can provide reasonable predictions ...

Extensive use is made of the normalized soil behaviour type (SBTn) chart based on normalized cone resistance (Qt) and normalized friction ratio (Fr). Updates are provided regarding the normalization proc-ess and its application to the identification of soil type.

referredtoasasoilbehaviourtype(SBT)classification.However,someconfusionexists,sincemostCPT-basedSBTclassification systems use textural-based descriptions, such as sand and clay. This paper presents an update of popular CPT-based SBT

Classification of soils according to Robertson (1986 or 2010) is based on the measured values of penetration resistance qc, local skin friction fs, pore pressure u2 respectively.

2019年12月2日 · Hence, a CPT soil classification chart is technically referred to as a Soil Behavior Type (SBT) chart. Most CPT soil charts are derived from tip resistance (or normalized tip resistance, Qt) and friction ratio data .

– SBTn charts and empirical correlations work well Soils with significant microstructure (K* G > 330) – SBTn charts and empirical correlations may not always apply & local modification may be needed – If fine-grained, Qtn –U2 chart may aid in identification of microstructure (U2 …

Many procedures have been published for estima... ... 1990 developed a chart to identify soil behavior type SBT based on normalized CPT parameters as shown in Fig. 1. The CPT …

Grain characteristics can be estimated directly from CPT results using soil behavior type (SBT) charts. The CPT SBT charts show a clear trend of increasing friction ratio with increasing fines content and decreasing grain size.

In general, CPT-based SBT classification charts obtained from Robertson (2016) show a good agreement with the visual observations. The Robertson (2016) SBT charts indicate that...