--- wildboarwrote: > Thanks for your informative reply. We do realize > that there is "settling" > of structures that would produce cracks, etc. > However, the mine was dormant > for several years and development pursued. Some > even suggest that there > were some back-alley deals made in the what was > believed to be a period when > the mine was no longer in use. Evidence of large > cracks, pictures falling, > wells going dry, ....and most influential is a > letter from the State Fires > Marshall's office declaring that it is their opinion > that the blasting > causes "harm to life and property". Pretty > damaging. > > So, we are attacking this at all angles. The > monitoring suggestions you > have will be a benefit to us all. Thanks. > > Patrick Wilber > > ----- Original Message ----- > From: "Doug Crice" > To: > Sent: Wednesday, July 25, 2001 12:52 PM > Subject: Re: Hello > > > > There is a special class of seismographs used for > "blast monitoring" > > manufactured by Geosonics http://www.geosonics.com > , Instantel > > http://www.instantel.com/ , Vibratech and Thomas > Instruments > > http://www.vibration.com/index.htm > > > > These instruments use geophones as the basic > sensor, monitored > > continuously electronically, and they > automatically digitize and save > > any data with a vibration event. They are about > the size of a brick, > > and connect to a laptop. Software provided by the > companies analyzes > > the data for peak particle velocity, spectra, and > of course time of > > occurance. > > > > The basic units cost a few thousand dollars, and > they can be rented for > > some fraction of the cost. While it is possible > to construct your own > > device to measure these vibrations, it is highly > unlikely that the data > > would stand up in court. Whether you could rent > one and put together a > > credible case is also unlikely, since you would be > testifying against > > experts. Some of the companies listed above > provide the service. > > > > If you really want to attack this problem, the > surest approach is to > > hire your own consultant, preferably one smarter > and more prestigious > > than the one used by the mining company. The > mining company consultant > > may or may not be right. I should caution you also > that a lot of blast > > damage is imaginary. Cracks appear in houses and > sidwalks for a variety > > of reasons and they always get blamed on blasting > when there is some in > > the area. > > > > > wildboar wrote: > > > > > > Dear Folks, > > > > > > I am new to this site and my knowledge of its > contents is limited. > > > The reason I am interested is that our community > lives near a mine > > > that blasts to recover product. The land use > has changed considerably > > > over the last 10 years (from agricultural to > > > ag-residential/residential/commercial) and we > are experiencing damage > > > due to the blasts. > > > > > > The "governing" authority for mines is the State > Fire Marshall...and > > > the laws governing mining are full of loop holes > at best. The > > > immediate problem is that the mine self-monitors > their blasting > > > activities through a subcontractor. First, many > in the community do > > > not believe that the mine always makes aware the > State when they are > > > to blast and second, we do not believe the > reported results are > > > accurate. > > > > > > What type of equipment could a home owner put in > place that could > > > monitor such activities, be defensible in court, > and be not to pricey? > > > > > > Thank you for your responses. > > > > > > Sincerely, > > > > > > Patrick Wilber > > > > -- > > Doug Crice http://www.georadar.com > > 19623 Via Escuela Drive phone 408-867-3792 > > Saratoga, California 95070 USA fax 408-867-4900 > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with > > the body of the message (first line only): > unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger http://phonecard.yahoo.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>