Landslides caused by a low magnitude earthquake swarm (2.8?≤?M?≤?3.6) in 2012 were documented at the Santa Rosa Canyon in northeastern Mexico. Disrupted landslides from falls and slides, in both rocks and soils, were identified based on fieldwork and high-resolution satellite imagery along stream banks from natural cliffs and along the road cut in the epicentral area. Most of the landslides occurred on slopes greater than 40°, where geological features played a key role in triggering slope instabilities. The maximum distance limit for disrupted slides from the epicentral area was 7 km. The area affected by landslides during the early stage of the seismic sequence (July through August 2012) was 90 km2. Landslide identification was limited in some areas by the resolution of the satellite imagery and dense cloud coverage. Both the epicentral distance and the area affected by landslides are above the global bounds reported in literature. The final landslide inventory is the first documented case of earthquake-induced landslides in northeastern Mexico. 相似文献
This paper presents a simple hypoplastic constitutive model that describes the essential features of the material behaviour of partially saturated clayey soils observed in oedometric compression tests. The model is formulated in terms of net stress and degree of saturation. The total strain rate is decomposed into a portion related to the changes in saturation and a portion for the evolution of net stress. However, no distinction is made between plastic and elastic strains. With this strain rate decomposition, the maximum swelling strain/stress are obtained by simulating wetting processes under constant stress/strain conditions. In addition to the void ratio, the model includes two scalar variables to track the loading history (preloading). The calibration of the model constants using common laboratory tests is discussed. Confined and unconfined swelling tests under oedometric conditions with subsequent loading and unloading phases carried out on three different materials were satisfactorily simulated by the model. Its promising results call for an extension to a 3D formulation.
Acta Geotechnica - This paper presents an approach for the automatic parameter calibration (AC) of a hypoplastic constitutive soil model. The calibration software developed in this work simplifies... 相似文献
The precise delineation of coastal areas subject to past, present, and future erosive processes plays a fundamental role in coastal risk management. Within this framework, satellite data represent a valuable synoptic and multi-temporal information source. Therefore, this research integrated remote sensing and GIS techniques for mapping and modeling shoreline evolution through time. Long-term shoreline’s proxy rates of advance and retreat were determined using Landsat data from the mid-1980s to 2011 and subsequently, a short-term scenario (3 years) was predicted and validated. Two different coastal environments, Oceanic and Mediterranean, were investigated. In the first, different proxies were analyzed, thereby enabling a multi-proxy analysis. Findings showed that the method provided more accurate results in higher energy environments (Oceanic) and where the coastline is not urbanized. Results also highlighted the importance of performing multi-proxy analyses in given study areas, to more reliably define shoreline modeling. Importantly, during the analyses, particular attention was given to assessing uncertainty, which is crucial when outcomes of scientific research are considered for management. 相似文献
Particularly in arid and semiarid areas, more and more populations rely almost entirely on imported water. However, the extent to which intentional discharge into transiting river
systems and unintentional leakage may be augmenting water resources for communities along and down gradient of the water transfer scheme has not previously been subject to research. The objective of this study was to assess both the potential of a large-scale water
transfer (WT) scheme to increase groundwater availability by channel transmission losses in a large dryland aquifer system (2,166 km²) in Brazil, and the capability of the receiving streams to transport water downstream under a prolonged drought. An integrated surface-water/groundwater model was developed to improve the estimation of the groundwater resources, considering the spatio-temporal variability of infiltrated rainfall for aquifer
recharge. Aquifer recharge from the WT scheme was simulated under prolonged drought conditions, applying an uncertainty analysis of the most influential fluxes and parameters. The annual recharge (66 mm/year) was approximately twice the amount of water abstracted
(1990–2016); however, the annual recharge dropped to 13.9 mm/year from 2012 to 2016, a drought period. Under similar drought conditions, the additional recharge (6.89 × 106 m³/year) from the WT scheme did not compensate for the decrease in groundwater head in areas that
do not surround the receiving streams. Actually, the additional recharge is counteracted by a decrease of 25% of natural groundwater recharge or an increase of 50% in pumping rate; therefore, WT transmission losses alone would not solve the issue of the unsustainable management of groundwater resources.
Predictive models for estimating strong-motion duration in sites characterized by soft-soil profiles are presented in this paper. The models were developed using a strong-motion database that includes observations from subduction interface earthquakes that occurred from 1989 to 2020 and recorded in Mexico City, which is located at source-to-site distances up to 600 km. A linear mixed-effects regression model, which is a statistical fitting procedure that allows to consider the correlation structure of grouped data, was used to develop the predictive models. Relative significant duration was selected to measure strong-motion duration. This measure can be directly associated with the accumulation of energy of the ground movement. The proposed predictive models relate relative significant duration with moment magnitude, either hypocentral distance or closest distance to the rupture plane, and dominant period of the soil. Regression analyses were performed grouping the ground-motion data by both seismic event and site class. Model assumptions, such as homoscedasticity, normality, and linearity of effects, were verified from residual analyses. From the results, the expected value of the natural logarithm of relative significant duration was found to be ~1.2 times greater for an earthquake with a moment magnitude equal to 8.0 than for one of 6.0. An insightful discussion about the sources and character of the uncertainties detected in the proposed predictive models is also presented in this study. The predictive models proposed in this paper are of valuable application in seismic and structural engineering because they allow to circumscribe properly the dimension and randomness of strong-motion duration. 相似文献
Natural Hazards - After an earthquake, a business often stops operating temporarily or permanently due to direct effects on the building (Initial security protocols and Physical damage to building... 相似文献
Natural Hazards - Disaster response involves the planning, coordination, and distribution of supplies in an effective manner to people in need. Recent natural hazards, such as hurricane Harvey,... 相似文献