Journal Papers by Jan D. Nieuwenhuis
Earth Surface Processes and Landforms, 36 (13), pp. 1705-1714, 2011
Due to various decay processes associated with weathering, the stability of artificial slopes in ... more Due to various decay processes associated with weathering, the stability of artificial slopes in weak rocks may be affected well within their envisaged engineering lifetime. Conceptually, the decay following the initial stress release after excavation can be described as a process seeking equilibrium between weathering and erosion. The extent to which such an equilibrium is actually reached influences the outcome of the weathering‐erosion decay process as well as the effects that the decay has on the geotechnical properties of the exposed rock mass, and thus ultimately the stability of slopes affected by erosion and weathering. This paper combines two conceptual models for erosion and weathering, and derives a numerical model which predicts the resulting slope development. This can help to predict the development of a slope profile excavated in a weak rock in time, and can be extended with the addition of strength parameters to the weathering profile to enable prediction of slope stability as a function of time.
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Environmental & Engineering Geoscience. 12 (1), pp. 39-51, 2006
Following the initial stress release after excavation of a road cut, weathering and erosion proce... more 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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Papers by Jan D. Nieuwenhuis
Engineering Geology, 1990
Abstract Nearly 10 years of observations and monitoring of several small landslides in varved cla... more Abstract Nearly 10 years of observations and monitoring of several small landslides in varved clays in the French Alps near La Mure have demonstrated that classical plane stability cannot explain their behaviour. The limited, seasonal movements of the slides are controlled by blocking mechanisms originating from the movements themselves. Of the three dominant mechanisms assumed to act here, viz., heaping up of slices near the lower edge of the slide, seasonal variations of the shear strength along the major slip plane and essentially convergent flow in the slide, the last mechanism is discussed in this paper. Both simple 3-D stability analysis and convergent plastic flow are shown to be capable of explaining the divergence between 2-D stability analysis and actual behaviour of the slide.
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After excavation of a road cut, weathering and erosion processes will start acting upon the newly... more After excavation of a road cut, weathering and erosion processes will start acting upon the newly exposed slope material. Field observations show that the resulting degradation caused by stress release, weathering and erosion may have significant effects well before the envisaged end of the engineering lifetime of the road cut. Since 1990 a road cut in Upper Muschelkalk limestone was monitored to study these effects. The classifications and laboratory test results show that degradation of the rock material and rock mass has progressively continued throughout this period, and threatens the stability of the current slope by causing a notable decrease of the bedding plane's friction angle. The test results also show the limited usefulness of shear box testing for slope stability assessment. The small size of shear box samples can lead to both a serious over- and underestimate of the in-situ shear resistance.
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Environmental and Engineering Geoscience, 2006
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Earth Surface Processes and Landforms, 2011
Skip to Main Content. Wiley Online Library will be disrupted 2 July from 10-12 BST for monthly ma... more Skip to Main Content. Wiley Online Library will be disrupted 2 July from 10-12 BST for monthly maintenance. ...
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Journal of Hydrology, 2005
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Journal Papers by Jan D. Nieuwenhuis
Papers by Jan D. Nieuwenhuis