Abstract: The invention relates to a security barrier for stopping a vehicle, comprising a base (2) which is designed to lie on the ground, a frame (3) which extends above the base (2) and is designed to absorb the impact of the vehicle, and a pair of loading structures (4) which are designed to connect the frame (3) to the base, wherein each loading structure (4) comprises a spur (14) which is designed to contact the ground from the side opposite the impact of the vehicle and which is connected to the base (2) by means of at least one hinge (22) that has an axis (A), said axis sliding relative to the loading structure (4) in a direction which is inclined downwards from the frame (3) to the spur (14).