Soil proﬁles (section through boreholes) are extremely helpful in enabling the designer to visualize the ground
conditions. This valuable aid is, in the authors’ opinion, too often given inadequate attention in site investigations.
Many foundation failures can be traced back to faulty visualization of the ground conditions due to inadequate soil proﬁles or misinterpretation of them. A typical soil proﬁle is shown in Fig. 3.7.
Most experienced designers would tend to study the soil proﬁle ﬁrst before reading the site report, studying the test results and checking other data. This makes for efﬁciency, better assessment of site conditions, improved judgement of data, it warns of problems and can indicate the need for possible further investigation.
Some typical misinterpretations or inadequate data leading to false conclusions and similar errors are shown in Fig. 3.8 (see also Figs 2.28, 2.29 and 2.31).
Fig. 3.7 Soil proﬁle for a typical site.
Fig. 3.8 Misinterpretation of soil proﬁle