least one centerjoining plate for joining the substantially u shaped forms 10 a 10 b and 10 c together as a unit in this embodiment the center joining plate is in the form of a disc 20 preferably the forms 10 a 10 b and 10 c are fastened to the joining means below the upper transverse portions 12 of the forms 10 a 10 b and 10 c means such as an anchor plate 24 attached to the bottom of the substantially u shaped forms 10 a 10 b and 10 c can also be provided to anchor the substantially u shaped forms 10 a 10 b and 10 c to a support surface the u201c footprint u201d of the assembly is governed by the transverse cross sections of the substantially u shaped forms 10 a 10 b and 10 c and the number of such forms that are nested the forms are not limited to tubing of circular cross section but can be made of tubing of other cross sections including but not limited to square or rectangular cross sections fig3 a 30d and fig3 a 30d show fifth and sixth embodiments 110 and 110 u2032 respectively of a bollard in which the forms 110 a 110 b 110 c and 110 d are made of tubing having a square cross section each substantially u.