【正确答案】MEMO
To Philip Green, Managing Director
From Ronald Young, Property Manager
Date 13 May 2002
Subject GEOPHYSICAL SURVEYS
I have just read some material on geophysical surveys, and I think we should start taking this matter seriously and include them in all our development plans. Like most companies, we are now spending only 0.2 percent of the total contract value on ground investigation; yet this is the most unpredictably variable in any building work as there are often nasty and expensive surprises.
You may recall the incident in Bury thirty years ago, when a housing project was disrupted by the discovery that old chalk mines were collapsing underneath the site. In a more recent example, a factory building had to be demolished for building on unstable rubbish tip. Imagine the impact on our reputation and our profit should our company be in such a situation.
Most of our urban developments are on brown field sites and I think it is vital for us to know how previous constructions have affected the land. Traditionally we have resorted to trial pits and bore holes to determine the stability of building land. But now these techniques are outdated as they may stir up some harmful deposits (chemical, heavy metals, etc.) underground.
The new technology-tomography-sends electromagnetic radiation or electricity into the ground and interprets the reflected signal. These systems are now available on a commercial basis and I really think we should start getting some quotations. I do not think it will be cheap, as we will need to hire equipment as well as a geotechnical specialist; however, investment in this is worthwhile considering the possible disastrous consequence of not conducting ground survey properly.
I have the names of several companies which offer this service and I intend to gather more information. Perhaps we could arrange a time to discuss this further.