This paper presents a practical methodology for optimization of concentrically braced steel frames subjected to forward directivity near-fault ground motions, based on the concept of uniform deformation theory. This is performed by gradually shifting inefficient material from strong parts of the structure to the weak areas until a state of uniform deformation is achieved. In this regard, to ove...

One of the most important reasons for damages during earthquakes is the liquefaction of loose and saturated sand soils. However, in many regions with proper soil specifications, the large settlements have been observed in the ground surface. Loose sand layers buried in fine soils are one of the cases which may result in these problems and as a weak point during earthquake can cause this phenome...

Because of difficulty in inspection and retrofit of foundation in comparison with other elements, the common design philosophy is to avoid any nonlinear deformation in the foundation. This paper shows that by employing controlled foundation nonlinearity, in predetermined sections with arrangements for inspection and retrofit, it is possible to reduce seismic demand on superstructure. Localizing...

Dense continuously-operating networks of GPS receivers (CGPS) have been established in many parts of the world in order to monitor ground deformation due to earthquakes and other activities. However, it has been found that the CGPS is still NOT dense enough to monitor some phenomena, e.g. volcano and ground subsidence due to mining. Therefore the authors propose to combine GPS with radar interf...

The 2002–2003 Stromboli eruption triggered the failure of part of the Sciara del Fuoco slope, which generated a tsunami that struck the island and the northern coastline of Sicily. The Sciara del Fuoco is a very steep slope where all lava flows from the craters’ emplacement; most lateral eruptions usually take place from fissures propagating in this sector of the volcano. The eruption went on t...

We used satellite interferometric synthetic-aperture radar (InSAR) data to document ground deformation across North America suspected to be caused by human activities. We showed that anthropogenic deformation can be measured from space across the continent and thus satellite observations should be collected routinely to characterize this deformation. We included results from the literature as w...

In the last years, the Ground-Based SAR (GBSAR) technique has proved to be a reliable tool for deformation measurement and monitoring. Compared with other point-wise geodetic techniques it can provide “continuous” displacement measurements over areas of few squared kilometers, with a high spatial resolution and precision up to millimeter level. The process of estimating deformation from the GBS...

We propose a novel geodetic network design method for InSAR that determines the minimum number and optimal locations of in situ devices for monitoring a deforming area within desired quality constraints (precision, reliability, economy). From field experiments, the use of low-cost active radar transponders has been validated, and their measurement precision estimated. The proposed design algori...

In this paper, a ground-based SAR interferometry technology was used to monitor major engineering. This technology has been recognized as a powerful tool for terrain monitoring and structural change detecting. Deformation monitoring for large project has been a hot issue among them. According to GBSAR interferometry principle and characteristics of IBIS system, the authors analysis the error so...