Response of structural elements of temporary wooden bridges subjected to contact detonation

The use of wood as a structural element is still commonly used in constructions, not only in civil engineering but also in military applications. The access to this material, its processing and the ability to create individual joins without advanced equipment are reasons why wood remains an important material in military operations. Another important argument is the use of wooden structures to build local crossings for the benefit of the state economy. The speed of construction and the cost of making for example a driving deck are many times lower. This is quite an important factor influencing the decision of local governments to rebuild temporary crossings. Moreover, the skilful use of this material can significantly help the army in terms of durability and effective manoeuvrability. Engineering troops can build shelters for people and equipment, as well as low-water and underwater bridges and crossings for armoured fighting vehicles from wood. Any destruction of wooden structures planned by the engineering troops must be based on calculations derived from knowledge and experience. This article presents experiments on contact explosions of wooden structural elements. Pine beams with an equal diameter of 23 cm were tested in the military field. The wooden log destruction has been inventoried and the damage to particular wooden tissues was quantified by using different amounts of explosives. Also, professional military analyses were conducted to determine the explosive mass to destroy such wooden logs. Later, the computed values were compared with the results obtained in the field experiment and a damage parameter of energy criteria for pine wood was determined for the constitutive model of wood including damage.