Analysis of cyclic swelling of mudrocks

Pejon, Osni José; Zuquette, Lázaro Valentin

doi:10.1016/s0013-7952(02)00147-3

Cited by 48 publications

(14 citation statements)

References 9 publications

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“…An important additional factor to note is the presence of small amounts of swelling clays in the Keuper shales (based on x-ray fluorescence/x-ray diffraction tests that are approximately 4 percent by volume, with a total clay amount of 25 percent to 30 percent). Kühnel (2002) described the importance even of small amounts of swelling clays, and cyclic swelling and shrinking is in such materials a dominant degradation process (e.g., Pejon and Zuquette, 2002).…”

Section: Parameters Controlling Weatheringmentioning

confidence: 99%

Predicting Rock Mass Decay in Engineering Lifetimes: The Influence of Slope Aspect and Climate

Huisman¹,

Hack²,

Nieuwenhuis

2006

Environmental and Engineering Geoscience

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Following the initial stress release after excavation of a road cut, weathering and erosion processes will start acting on the newly exposed slope material. As field observations show, the resulting degradation may have significant effects well before the envisaged engineering lifetime of the slope ends. The data set obtained by 12 years of fieldwork by the International Institute for Geo-Information Science and Earth Observation and Delft University of Technology was used to assess and quantify the time-related degradation of rock masses by weathering. The results of a bootstrap analysis of the data show a close relationship between the weathering rates, the slope aspect, and the prevailing wind directions during rainfall events. For the study area around Falset it can be concluded that in shales, marls, and similar materials containing clays (especially swelling clays), weathering rates are highest in slopes facing the prevailing winds during rainfall because of more frequent and intense cyclic wetting and drying. The same holds true for more resistant materials such as limestones, which are interbedded with weak materials such as shales and marls. In soluble materials such as the gypsum unit investigated here, water retention in slopes sheltered from the winds facilitates chemical weathering, and it is in these lee-side slopes that the highest weathering rates are found. These relations can be used to predict weathering rates and, therefore, also weathering degree as a function of time. With the use of a probabilistic slope-stability assessment method, the time-related slope stability can also be predicted.

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Section: Parameters Controlling Weatheringmentioning

confidence: 99%

Predicting Rock Mass Decay in Engineering Lifetimes: The Influence of Slope Aspect and Climate

Huisman¹,

Hack²,

Nieuwenhuis

2006

Environmental and Engineering Geoscience

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“…For example, Huggett () considers wetting and drying to be more or less synonymous with ‘slaking’, which refers to clay mineral hydration, whereas others (Yatsu ; Bland and Rolls ) note that wetting and drying may cause rock degradation even in rocks that contain little or no clay minerals. Although the mechanics of wetting and drying are not completely understood, studies have shown that rocks inundated in water will increase their dimensions over the period of a wetting event (Pejon and Zuquette ; Gonzalez and Scherer ), lending credence to the idea of hysteresis (Hall and Hall ).…”

Section: Introductionmentioning

confidence: 99%

“…For example, Wells et al . () saturated samples for over 5000 cycles, but Pejon and Zuquette () used a maximum of only 11 cycles. Sumner and Loubser () saturated the samples for 52 cycles, with Hall and Hall () applying 140 cycles.…”

Section: Introductionmentioning

confidence: 99%

Weathering of basalt and sandstone by wetting and drying: a process isolation study

Loubser

2013

Geografiska Annaler: Series A, Physical Geography

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Loubser, M.J., 2013. Wetting and drying weathering of basalt and sandstone: A process isolation study.ABSTRACT. Rock samples from Marion Island in the SubAntarctic and from the Drakensberg, South Africa were divided into sets and subjected to wetting and drying at two different moisture amplitudes to determine changes in physical rock properties. The rock samples were subjected to a total of 105 wetting and drying cycles. Rock porosity and water absorption capacity was determined both at the beginning and at the end of the experiment and compared. Results varied from set to set, but not as a result of variations in moisture amplitude. Three key findings are presented. First, it seems that the number of wetting and drying cycles is a more important factor than the degree to which the samples have been saturated. Second, changes in rock properties were detected for the control samples as well as the field samples, suggesting that the experimental techniques used for determining the rock properties have themselves affected the samples. Third, samples that outwardly appeared very similar have responded differently to wetting and drying. This implies that even small changes in internal rock structure can have a profound effect on the ultimate nature of the weathering taking place.

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“…In a tunnel, Butscher et al (2011a, b) concluded that excavation-induced groundwater inflow into anhydritic layers and caused rock swelling. Pejon and Zuquette (2002) and Moosavi et al (2006) indicated that deformation of a roadway in swelling soft rock depended on mineralogy, lithology, ground characteristics, hydrology, stress state, and weathering conditions. In addition to this, using an artificial neural network, Doostmohammadi et al (2008) investigated the swelling potential of mudstone.…”

Section: Introductionmentioning

confidence: 99%

Effect of bolting on roadway support in extremely weak rock

Shi

Qin

2016

SpringerPlus

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In mine roadway support operations, floor bolting not only played a role in floor heave control, but also in reinforcing roof and its two sides. Correspondingly, bolting of roof and two sides also played a part in floor heave control. To quantify the effect of such bolting, based on roadway support in extremely weak rock, three physical models were produced and tested in laboratory. Through comparison of their displacements in three physical simulation experiments, the reinforcing effect of bolting in extremely weak rock roadways was quantified. Reinforcing coefficients was defined as displacement ratio between original support and new support regime. Results indicated that the reinforcing coefficients, for bolting of roof and its two sides, on floor, two sides, and roof reached 2.18, 3.56, and 1.81 respectively. The reinforcing coefficients for floor bolting on floor, two sides, and roof reached 3.06, 2.34, and 1.39 respectively. So in this extremely weak rock, the surrounding rock should be considered as an integral structure in any support operation: this allows for better local strength improvement, and provided future design guidance.

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Analysis of cyclic swelling of mudrocks

Cited by 48 publications

References 9 publications

Predicting Rock Mass Decay in Engineering Lifetimes: The Influence of Slope Aspect and Climate

Predicting Rock Mass Decay in Engineering Lifetimes: The Influence of Slope Aspect and Climate

Weathering of basalt and sandstone by wetting and drying: a process isolation study

Effect of bolting on roadway support in extremely weak rock

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