Concerning the stipulation and statement for empirical formula and revised index in pointloading strength test there are still some uncertainties in related specifications and manuals.
Through the X-ray diffraction analysis and pointloading strength test, intrinsic causes for the rockburst in some sandy mudstones in Erlang mountain highway tunnel has been ascertained.
Measures to improve the properties of PVC pipes were introduced. The excellent impact property, anti-fracturing property, anti-pointloading capacity and weldability of PVC-M pipes were introduced.