Creep, strength and other characteristics of Hawaiian volcanic soils

Abstract

Strength, creep and other properties of four volcanic soils from Hawaii were investigated under reconstituted triaxial conditions. The selected soils are of different geological origin and have contrasting index properties. Results from triaxial tests suggest that as clayey volcanic soils weather toward a siltier texture, their response to loading changes accordingly, with dilation at larger strains leading to an increase in strength. The frictional strength of two of these soils, a high-plasticity clay from Manoa Valley in Honolulu and a young ash soil from the Hilo area, does not correlate well with conventional empirical relations. In terms of creep behaviour, the response under constant stress conditions can be described, at least to a first order, with a simple rate process equation. A constant that is a measure of strain rate attenuation with time is observed to be stress level dependent at lower deviatoric stresses, but relatively constant at higher stress levels. This constant may be related to plasticity index, although such a correspondence is tenuous at best. Strength gain is observed in post-creep undrained tests, and is attributed in part to prior volume changes and in part to ageing. In terms of changes to the short-term failure envelope, the effect of a sustained creep phase of 100 days or longer is to shift the failure line upward, albeit at a constant angle.

Geotechnical Characterization of Quito’s North-Central Zone as Applied to Deep Excavation in the Urban Setting

“…With regard to the parameters obtained from the oedometric tests, the C c soil values in this study (0.06-0.36) are similar to those determined by Hürlimann et al [14] for the volcanic soils of Tenerife (Spain), where the value for this index was 0.287. Conversely, the C c value range of this survey is similar to the C c value of 0.22 obtained for volcanic soils identified as medium-plasticity red silt (ML) from Kapolei, Hawaii (USA), and much less than the C c value of 0.49 for the high-plasticity brown clay (CH) in this same zone obtained by Brandes and Nakayama [13].…”

“…This study's soil classification is consistent with the volcanic soil classifications of other researchers, as is the case with Hürlimann et al [14], who worked with soils in Tenerife, Canary Islands (Spain), and mainly identified them as silty sands (SM); Crosta et al [10], who investigated the volcanic soils of the Santa Tecla (El Salvador) zone and recognized the presence of low to high-plasticity silts (ML and MH), medium-plasticity clays (CL), and silty sands (SM); and Brandes and Nakayama [13], who studied the volcanic soils in the islands of Oahu and Hawaii (USA), which were identified as medium-to-high plasticity silts (ML and MH) and high-plasticity clays (CH) and silty sands (SM).…”

“…Volcanic soils constitute one of the most widely distributed groups in the world, especially in the Central and South American zones, Pacific Ocean islands, and the Caribbean, Africa, and Indonesia [9]. Thus, authors such as Bommer et al [9], Crosta et al [10], Gonzalez de Vallejo et al [11], del Potro and Hürlimann [12], and Brandes and Nakayama [13] have presented various detailed surveys on volcanic soils at the international level, in which they present the different characteristics of these soils, focusing mainly on their basic properties, soil classification, compression and strength properties. However, studies carried out by researchers such as Hürlimann et al [14], Moon et al [15], Avşar et al [16], and Okewale and Coop [17], in addition to the abovementioned properties, also include mineralogy and microstructure analyses.…”

Extended Residual-State Creep Test and Its Application for Landslide Stability Assessment

“…In the primary and secondary stages of creep, soil materials are in a stable condition, but they may collapse when reaching the tertiary stage of creep. Many extensive laboratory investigations have been conducted with triaxial apparatus and oedometers to examine the creep behavior of various kinds of soils [ 18 , 19 , 20 ], but almost all of them focus only on the pre-peak-state creep behavior of soil materials. Numerous theories, equations and models have been proposed to account for the creep behavior of clayey soils [ 21 , 22 , 23 ] and various geotechnical issues [ 24 , 25 ].…”

Weathering and soil genesis from the Nasinu Basalt, South-East Viti Levu, Fiji

“…Some research has been completed on the weathering of basalts in Fiji (Bonato and Morrison, 2012;Morrison et al, 1986Naidu et al, 1987), but few studies have looked comprehensively at the parent material chemistry, mineral transformations during weathering, and the resulting soil chemistry. There has also been ongoing interest in 'laterisation' (Brandes and Nakayama, 2010;Ollier, 1994;Schellmann, 1981), as this has been observed frequently in parts of the Fiji Archipelago, particularly associated with pedological studies, and the bauxite and manganese mining operations of the 1940s and 1950s (Colley, 1976;Morrison et al, 1987;Twyford and Wright, 1965). This study was initiated to examine the weathering products of the Nasinu Basalt, a relatively extensive area of basalt flows in south-east Viti Levu, the main island of the Fiji group to see if laterisation is occurring.…”