Experimental determination of stress on an 11th century gypsum column in the crypt of an ancient German church

The four columns of the St. Ulrich's church in Rastede are thought to originate from the 11th century. A close look at the columns gave rise to reservations about stability. To verify the stability, the method of raising the capital with the supported vault to relieve the columns was sought. Test equipment including hydraulic jack set up at the point of measurement was used to raise the capital. Eight strain-gage measuring points evenly distributed around the circumference at the upper and lower ends of the approximately 1 m long column shaft measured the strain. Results show that despite the visible cracks and leaning attitude of the column under study, the measurements for the present loading conditions of the column do not give reason for suspecting any risk.