Investigation Of Surface Deformation Research Articles

An investigation of surface deformation over oilfield in Southwest Iran (2003–2010) using InSAR and physical modelling

ABSTRACT Land subsidence is one of the most hazardous phenomena. Rapid rate subsidence corresponds to human activities such as subsurface withdrawal. Therefore, local changes in surface elevation and its associated response has the potential to damage the industrial structures. In this research, the small baseline subset (SBAS) algorithm is applied to perform an Interferometric Synthetic Aperture Radar (InSAR) time series analysis within 2003 and 2010 over a giant oilfield located in the Zagros fold-thrust belt in southwest of Iran. Thirty-one interferograms are generated using 18 Envisat ASAR images. The mean velocity map obtained in the Line-Of-Sight (LOS) direction of satellite to the ground reveals the maximum subsidence on order of 17.3 mm per year over the field due to both tectonic and non-tectonic features. In order to assess the effect of non-tectonic features such as petroleum exploitation on surface displacement, the results of InSAR have been compared with the oil production rate. Also, a physical model of reservoir pattern has been developed using 2D seismic profiles as the way to estimate tectonic deformation which indicates the influence of depth variations of the Gachsaran salt decollement on structural style.

Investigation of Surface Deformation in Lower Jehlum Valley and Eastern Potwar using SRTM DEM

This study describes the surface deformation in lower Jehlum and eastern Potwar using remotely sensed Shutter Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) to identify regional uplift rates. Mapping of active surface deformations help to predict seismic hazards. DEMs are the fundamental input factors that identify the surface geometry and its belongings. These belongings include stream offset, elevation, and slope breaks within a contributing area. This study provides an evidence of tectonic activity and its impact on regional drainage network using SRTM DEM. Various indices including concavity and steepness were computed using power law in steady state conditions. We prepared the drainage network map of the study site showing uplift rates in mm/year. The deflection in stream network proves the existence of active fault in this region which controls the local drainage network. The results prove the relative uplift along Main Boundary Thurst (MBT) and the impact of active tectonic on evolving young organs.

Optimized SESAMs for kilowatt-level ultrafast lasers.

We present a thorough investigation of surface deformation and thermal properties of high-damage threshold large-area semiconductor saturable absorber mirrors (SESAMs) designed for kilowatt average power laser oscillators. We compare temperature rise, thermal lensing, and surface deformation of standard SESAM samples and substrate-removed SESAMs contacted using different techniques. We demonstrate that for all cases the thermal effects scale linearly with the absorbed power, but the contacting technique critically affects the strength of the temperature rise and the thermal lens of the SESAMs (i.e. the slope of the linear change). Our best SESAMs are fabricated using a novel substrate-transfer direct bonding technique and show excellent surface flatness (with non-measureable radii of curvature (ROC), compared to astigmatic ROCs of up to 10 m for standard SESAMs), order-of-magnitude improved heat removal, and negligible deformation with absorbed power. This is achieved without altering the saturation behavior or the recovery parameters of the samples. These SESAMs will be a key enabling component for the next generation of kilowatt-level ultrafast oscillators.

夹紧力作用下镜面变形及夹紧重复性研究

夹紧力作用下镜面变形及夹紧重复性研究

An investigation of surface deformation after fully mechanized, solid back fill mining

The surface deformation after fully mechanized back filling mining was analyzed. The surface deformation for different backfill materials was predicted by an equivalent mining height model and numerical simulations. The results suggest that: (1) As the elastic modulus, E, of the backfill material increases the surface subsidence decreases. The rate of subsidence decrease drops after E is larger than 5GPa; (2) Fully mechanized back fill mining technology can effectively control surface deformation. The resulting surface deformation is within the specification grade I, which means surface maintenance is not needed. A site survey showed that the equivalent mining height model is capable of predicting and analyzing surface deformation and that the model is conservative enough for engineering safety. Finally, the significance of establishing a complete error correction system based on error analysis and correction is discussed.

A numerical slipline field for the sliding cylinder problem

This paper presents a slipline field solution for a rigid cylindrical asperity sliding across an initially plane surface of a softer material. The numerical development of the model is described. The friction and strain pattern predictions of the model are tested against the results of experiments and finite element analysis. It is shown that the friction predictions of the model developed are in good agreement with the chord approximation model proposed by Challen and Oxley [J.M. Challen, P.L.B. Oxley, Slipline fields for explaining the mechanics of polishing and related processes, Int. J. Mech. Sci. 26 (6–8) (1983), 403–418]. Thus, it can predict well the friction coefficients measured from tests when a cylinder, whose trailing edge has been removed, slides across an aluminium alloy, as shown experimentally in Busquet and Torrance [M. Busquet, A.A. Torrance, Investigation of surface deformation and damage when hard cylindrical asperity slides over a soft smooth surface, Proc. 25th. Leeds-Lyon Symp. Tribol. (1998)]. However, this model is not suitable for predicting the friction coefficients when a full cylinder slides on aluminium. This has already been explained partly by the fact that the slipline field theory neglects elastic effects and also by the presence of detached particles trapped in the contact. The strain pattern calculated by the model presented here is much closer than the chord model of Challen and Oxley [J.M. Challen, P.L.B. Oxley, Slipline fields for explaining the mechanics of polishing and related processes, Int. J. Mech. Sci. 26 (6–8) (1983) 403–418] to visioplastic measurements of strain patterns produced by wedge-shaped asperities [Y. Yang, The prediction of the wear rates of ductile materials through their surface strains, PhD thesis, Trinity College, University of Dublin, September 1997], and this without strain-hardening. Furthermore, the morphology of the debris produced during wedge experiments has been explained to some extent by the model presented here without involving elastic effects.

The investigation of surface deformation: L. Grunberg, D. Scott and K. H. R. Wright, Brit. J. Appl. Phys., 12 (4), April 1961, 134–140

The investigation of surface deformation: L. Grunberg, D. Scott and K. H. R. Wright, Brit. J. Appl. Phys., 12 (4), April 1961, 134–140

The investigation of surface deformation

The methods for studying surface deformation used in the National Engineering Laboratory are described. Deformed metal surfaces show an enhanced photoelectric emission which is studied with the aid of open-ended Geiger-M?ller counters or electron multipliers. Oxide films stripped from deformed metal surfaces are studied by electron-microscopy and changes in chemical reactivity by radioactive tracers. Surface topography is an important factor in lubrication and wear research and is being studied with the aid of interferometry, phase contrast and electron microscopy. Replica techniques are often applied with advantage.