Results 81 to 90 of about 205,187 (293)

Stratigraphy of Tithonian (Ohauan-Puaroan ) marine beds near Port Waikato, New Zealand, and a redescription of Belemnopsis aucklandica (Hochstetter). [PDF]

, 2001
Some 1500 m of marine Ohauan and Puaroan strata in the Port Waikato region of New Zealand are restudied in an attempt to resolve lithostratigraphic and biostratigraphic anomalies in published works.
Challinor, A.B.
core   +2 more sources

Probability prediction of true‐triaxial compressive strength of intact rocks based on the improved PSO‐RVM model

Deep Underground Science and Engineering, EarlyView.
In this work, we propose an improved particle swarm optimization (PSO) algorithm and develop an improved PSO‐relevance vector machine (RVM) model as a substitute for traditional true‐triaxial testing. The model's high prediction accuracy was validated through comparisons with two other machine learning methods and five three‐dimensional Hoek–Brown type
Qi Zhang, Maohui Wang, Ning Wang, Yixin Shen, Xuzhen He   +4 more
wiley   +1 more source

Effect of confining pressure on fracture characteristics and mineralogical behavior of tight sandstone specimens after hydraulic fracturing

Deep Underground Science and Engineering, EarlyView.
Hydraulic fracturing in tight sandstone and fracture propagation characteristics using backscattered electron‐scanning electron microscope (BSE‐SEM) images. Abstract This study focuses on hydraulic fracturing experiments conducted under triaxial conditions on tight sandstone specimens from Shivpuri district, Madhya Pradesh, India.
Pankaj Rawat, Narendra Kumar Samadhiya
wiley   +1 more source

Resonance‐induced restoration of rock permeability degraded by heavy components of crude oil

Deep Underground Science and Engineering, EarlyView.
Resonance‐induced changes occur in filtration properties of sedimentary rocks in crude paraffin oil flow under acoustic vibrations. Experimental data on (a) pressure drop; (b) permeability; (c) pressure at the rock inlet; and (d) pressure at the rock outlet are presented.
Evgenii Riabokon, Qian Yin, Mikhail Guzev, Mikhail Turbakov, Evgenii Kozhevnikov, Nadezhda Riabokon, Ivan Panteleev   +6 more
wiley   +1 more source

The 'Maagdentoren' of Zichem (Belgium) : damage assessment of ferruginous sandstone by X-ray tomography [PDF]

, 2010
The ferruginous sandstone of the gothic “Maagdentoren” is suffering from a specific biological deterioration process triggered by perforating activities of mason bees.
Boone, Matthieu, Cnudde, Veerle, De Clercq, Hilde, Dusar, Michiel, Hayen, Roald   +4 more
core   +1 more source

The Transformation of Sediment Into Rock : Insights From IODP Site U1352, Canterbury Basin, New Zealand [PDF]

, 2017
ACKNOWLEDGMENTS We thank the crew of the RV JOIDES Resolution for professional seamanship, excellent drilling, and the scientific support on board. GHB and SCG thank the Australia–New Zealand IODP Consortium (ANZIC), and KMM thanks the Consortium for ...
Browne, Greg H., Carson, David, Dinarès-Turell, Jaume, George, Simon C., IODP Expedition 317 Scientific Party, Jaeger, John M., Kemp, David B., Marsaglia, Kathleen M., Richaud, Mathieu   +8 more
core   +1 more source

Creep properties and constitutive model of diabase in deep water conveyance tunnels

Deep Underground Science and Engineering, EarlyView.
The axial and lateral creep characteristics of diabase were analyzed based on compression creep tests. The nonlinear viscoelastic‐plastic model capable of describing the whole creep process was established based on the fractional derivative and damage theories.
Zhigang Tao, Pengxiao Guan, Xiaojie Yang, Keyuan Liu, Mingjiu Cai, Hong Yang   +5 more
wiley   +1 more source

Failure characteristics and the energy criterion of rock with a through‐going joint under true‐triaxial unloading conditions: Insights from the DEM model

Deep Underground Science and Engineering, EarlyView.
The rock failure mode is significantly influenced by the contributing factors, such as the joint inclination, the initial confining pressure, and the unloading point. We found six typical rock failure modes after a large number of numerical tests. Abstract Excavation unloading damages rock masses, with preferential failure along geological defects in ...
Fei Liu, Changhui Liang, Sijia Liu, Yongjun Zhang, Luo Wang   +4 more
wiley   +1 more source

Cenozoic sedimentary and volcanic rocks of New Zealand: A reference volume of lithology, age and paleoenvironments with maps (PMAPs) and database. [PDF]

, 2015
This volume presents descriptive geological data and text about each Cenozoic sedimentary and volcanic geological unit to formation and member level (in some cases) exposed on land in New Zealand, including their lithology, stratigraphic age and inferred
Kamp, Peter J.J., Tayler, Michael J.S., Vincent, Kirsty A.   +2 more
core   +1 more source

Permeability evolution during progressive development of deformation bands in porous sandstones [PDF]

, 2003
[1] Triaxial deformation experiments were carried out on large (0.1 m) diameter cores of a porous sandstone in order to investigate the evolution of bulk sample permeability as a function of axial strain and effective confining pressure.
Antonellini, Antonellini, Aydin, Aydin, B. T. Ngwenya, Beach, Bruno, Caine, Crawford, Evans, Fowles, Gibson, Grueschow, Hippler, I. G. Main, Jamison, Knipe, Knipe, Knott, Main, Main, Main, Mair, Mair, Manzocchi, Menendez, Moore, Ngwenya, Ngwenya, Ngwenya, O. Kwon, Ogilvie, Popp, Ramsay, Rhett, Rojstaczer, Rudnicki, S. C. Elphick, Scholz, Scott, Shipton, Sibson, Sverdrup, Taylor, Tuefel, Underhill, Wong, Zang, Zhang, Zhu, Zhu, Zoback   +51 more
core   +3 more sources