Blast Induced Damage and Dynamic Behaviour of Hangingwalls in Bench Stoping

This paper presents the results of a comprehensive monitoring program designed to investigate the extent of blast induced damage experienced by rock masses extracted by bench stoping methods. An array of triaxial geophones and extensometers were used to monitor blast vibration attenuation and measure hangingwall deformations during stope extraction. In addition, pre and post surveys of the hangingwall rock mass were conducted using a TV borehole camera and cavity survey instrumentation. These surveys were later used to calibrate damage profiles into the stope hangingwalls.

Peak particle velocity, hangingwall deformation measurements and stope surveys were used to develop a site specific damage model that allowed engineers to asses drilling and blasting configurations to minimise the extent of pre-conditioning and damage. In addition the study included the analysis of the frequency response, displacements and accelerations experienced by the excavation as extraction and mine filling progressed. This work aimed at improving our understanding of the influence of blasting on the dynamic behaviour of stope hangingwalls.

The study demonstrated that estimates of the maximum extent of rock mass pre-conditioning and/or damage made through the application of the Holmberg-Persson approach compared well with measured results. In addition, the study found that dynamic loading imparted on an exposed hangingwall from subsequent stope blasting was also expected to contribute to rock mass weakening and that mine filling was crucial to arrest further deterioration. Hangingwall accelerations were used to demonstrate that larger openings may be more susceptible to dynamic loading.     

Active faulting at the Eurasian, North American and Pacific plates junction

The active faults known and inferred in the area where the major Pacific, North American and Eurasian plates come together group into two belts. One of them comprises the faults striking roughly parallel to the Pacific ocean margin. The extreme members of the belt are the longitudinal faults of islands arcs, in its oceanic flank, and the faults along the continental margins of marginal seas, in its continental flank. The available data show that all these faults move with some strike-slip component, which is always right-lateral. We suggest that characteristic right-lateral, either partially or dominantly, kinematics of the fault movements has its source in oblique convergence of the Pacific plate with continental Eurasian and North American plates. The second belt of active faults transverses the extreme northeast Asia as a continental extension of the active mid-Arctic spreading ridge. The two active fault belts do not cross but come close to each other at the northern margin of the Sea of Okhotsk marking thus the point where the Pacific, North American and Eurasian plates meet.     

Pollution history and recovery of a boreal lake exposed to a heavy bleached pulping effluent load

We examined the effects of heavy pulp mill discharges on the Lake Lievestuoreenjärvi ecosystem and the later recovery of diatom and chironomid communities from age-dated short core samples. Beginning in 1927 the lake received a heavy effluent load from a sulphite pulp mill. Except for the recession during the Second World War and the temporary closure of the mill from 1967 to 1971, the industrial load, containing large quantities of nutrients, organic matter and toxic compounds, increased continuously. In the early 1980s, laboratory documents were falsified by the directors of the mill and the systematic illegal effluent overload led to a collapse of the whole lake ecosystem. In 1985, the outdated plant was finally closed down. Based on the assessment of chemical properties and biological remains of the sediment, we distinguished five developmental phases in the ecological state of the lake. In the pre-industrial phase, the pelagic and profundal benthic communities were dominated by species preferring ultraoligotrophic or oligotrophic lakes. Concomitant with the increasing discharge and deposition of chlorine compounds, resin acids, and mercury, as well as strong acidity and hypolimnetic and epilimnetic anoxia, the ecological status changed in a short period from excellent to bad. Finally, in the early 1960s, the majority of the lake was virtually dead and the aquatic life survived only in the uppermost littoral zone. Since 1985, a fast recovery in the water quality has led to a strong, but temporary eutrophy in pelagic communities. The main peak of eutrophication was caused by the invasion of a species new to the lake,Aulacoseira granulata var.angustissima. Later, the pelagic communities shifted towards oligotrophy, but the original, pre-industrial status has not been re-established. The profundal benthic communities have not achieved the pre-industrial structure, but at present indicate mesotrophy.     

A macroscale analysis of coastal steepening around the coast of England and Wales

Coastal steepening potentially presents an array of management issues in the form of financial implications of sea defence degradation, increased risk posed to the hinterland as wave attenuation is reduced, 'coastal squeeze' and statutory requirements in the light of the Habitats Directive. The extent to which coastal steepening has occurred throughout England and Wales has been investigated through use of a GIS and dataset based on historical Ordnance Survey map information. Data were collected along 1084 selected profile lines, positioned so as to be geomorphologically representative of the coast. Features recorded from each map year included the positions of mean high water (MHW) and mean low water (MLW), the relative movements of which infer changing intertidal gradients. The results presented in this paper are on a subject and scale not previously published. It is revealed that 61% of the coastline studied has experienced a tendency towards steepening. Of the remainder, 33% has flattened, and 6% has experienced no rotational movement. This tendency towards steepening has been the dominant movement on each of the west, south, and east coasts.     

Automatic Road Change Detection and GIS Updating from High Spatial Remotely-Sensed Imagery

This paper presents a tramework for road network change detectlon In order to upctate the Canadian National Topographic DataBase (NTDB). The methodology has been developed on the basis of road extraction from IRS-pan images (with a 5.8 m spatial resolution) by using a wavelet approach. The feature matching and conflation techniques are used to road change detection and updating. Elementary experiments have showed that the proposed framework could be used for developing an operational road database updating system.     

Data Fusion in Distributed Multi-sensor System

This paper presents a data fusion method in distributed multi-sensor system including GPS and INS sensors“ data processing. First, a residual X^2-test strategy with the corresponding algorithm is designed.Then a coefficient matrices calculation method of the information sharing principle is derived. Finally, the federated Kalman filter is used to combine these independent, parallel, real-time data. A pseudolite (PL) simulation example is given.     

Changes in soil organic carbon and other physical soil properties along adjacent Mediterranean forest, grassland, and cropland ecosystems in Turkey

Cultivation, overgrazing, and overharvesting are seriously degrading forest and grassland ecosystems in the Taurus Mountains of the southern Mediterranean region of Turkey. This study investigated the effects of changes on soil organic carbon (SOC) content and other physical soil properties over a 12-year period in three adjacent ecosystems in a Mediterranean plateau. The ecosystems were cropland (converted from grasslands in 1990), open forest, and grassland. Soil samples from two depths, 0–10 and 10–20 cm, were collected for chemical and physical analyses at each of cropland, open forest, and grassland ecosystems. SOC pools at the 0–20 cm depth of cropland, forest, and grassland ecosystems were estimated at 32,636, 56,480, and 57,317 kg ha⁻¹, respectively. Conversion of grassland into cropland during the 12-year period increased the bulk density by 10.5% and soil erodibility by 46.2%; it decreased SOM by 48.8%, SOC content by 43%, available water capacity (AWC) by 30.5%, and total porosity by 9.1% for the 0–20 cm soil depth (p<0.001). The correlation matrix revealed that SOC content was positively correlated with AWC, total porosity, mean weight diameter (MWD), forest, and grassland, and negatively with bulk density, pH, soil erodibility factor, and cropland. The multiple regression (MLR) models indicated that any two of the three ecosystems and one of the two soil depths accounted for 86.5% of variation in mean SOC values ((p<0.001).