The average shear stiffness values of the bolted concrete blocks are 148.12 kN/mm, 150.42 kN/mm, and 170.95 kN/mm for shear plane angles of 63[degrees], 58[degrees], and 53[degrees], respectively.
As expected, the contribution of bolts to the postpeak shear behavior of the bolted samples is more significant as the bolt diameter increases, verifying the favorable effect of bolts on jointed rocks .
When a bolt diameter is small (no more than 2 mm), the residual shear strength envelope of the bolted concrete block overlaps with that of the nonbolted sample.
[14.] VDI 2230 Part-1, Systematic calculation of high duty bolted
joints with one cylindrical bolt, Verein Deutscher Ingenieure.
"Over the past 11 years on various projects under my supervision we have developed and implemented bolted joint assembly procedures that have incorporated the principles contained in PCC-1-2000 and the revision of that document, PCC-1-2010," Lowery said.
Project managers may even find they can negotiate a bonus based on reduced bolted flange joint leakage for the first five years of operation.
By applying these practices, they will come to be associated with producing good work and leak-free bolted flange joints.
The average person generally would blame vibration as the chief culprit, but several studies indicate the main reason is insufficient preload, allowing side-to-side slippage of bolt relative to the bolted joint members.
BOLTCALC, a Windows-based program, enables users to calculate bolt load, torque, and tension in bolted joints by selecting a basic joint specification and inputting only one of several critical fastening parameters.
Typically an average size oil, gas or petrochemical facility will contain in the region of 30,000 to 50,000 bolted joints, all of which have the potential to leak and create a risk to the plant, the environment and potential loss of life.
So how can the whole process around "Bolted Joint Integrity" be improved and implemented, to help reduce the risks and costs related to loss of life, assets, environmental issues and project completion delay penalties?
While the primary complaint against using torque wrenches is their cost, the accuracy the user buys pays off in greater reliability of bolted
joints and greater peace of mind.
Based on the test results, it was decided that areas with relatively high-rock strengths would be bolted
with a minimum of two rows of bolts at the crest installed on a 1.5 x 1.5-m pattern.