A secondary or supporting stroke center may not meet all of the requirements of. a Primary Stroke Center (PSC) to deliver acute stroke treatment capability 24/7. but must meet all of the following requirements and submit a plan that.
The most common causes of subsidence are as follows: 1. Settlement of old mine workings, often at great depth, resulting in damage to structures on the surface. These may often be a long way from the cause of the damage. Access shafts are notoriously difficult to identify as mine operators rarely kept good records of these points. 2. Damage to subsoils caused by water flowing through them. This may be from naturally occurring ground water or leaking drains and water mains.
The resultant surface impacts and damages can be similar, however the mechanisms that trigger the subsidence are dramatically different. In abandoned mines, troughs usually occur when the overburden sags downward due to the failure of remnant mine pillars, or by punching of the pillars into a soft mine floor or roof.