A mounting bracket assembly comprising: a mounting bracket capable of extending laterally across a top surface of a trench-forming assembly, wherein the trench-forming assembly includes a longitudinal form body in engagement with a pair of opposed longitudinal frame members; and a pair of hook members capable of being carried by the mounting bracket, wherein each hook member is capable of removably engaging a downwardly facing surface of a respective frame member of the trench-forming assembly, wherein each hook member includes a hook portion each of which hook portion faces the other such that the hook members are capable of engaging the downwardly facing surfaces of the frame members, wherein each hook members includes an arm portion and defines a slot extending lengthwise along said arm portion; characterized in that the mounting bracket assembly further comprises a pair of wedge members capable of extending through the slots to thereby secure the hook members in engagement with the downwardly facing surfaces of the frame members, wherein the mounting bracket assembly is structured such that when the wedge members are extended through the slots, the respective upper ends of the slots ride up on the angled edge of the wedge members, as the hook portions of the hook members are urged upwardly toward and into contact with the downwardly facing surface of a respective frame member of the trench-forming assembly, wherein the arm portions extend at least partially through a respective aperture defined by the mounting bracket and are disposed at an acute angle relative to the mounting bracket directed away from the respective frame member, such that the hook portions of the hook members move towards each other as the wedge members are extended through the slots. a mounting bracket capable of extending laterally across a top surface of a trench-forming assembly, wherein the trench-forming assembly includes a longitudinal form body in engagement with a pair of opposed longitudinal frame members; and a pair of hook members capable of being carried by the mounting bracket, wherein each hook member is capable of removably engaging a downwardly facing surface of a respective frame member of the trench-forming assembly, wherein each hook member includes a hook portion each of which hook portion faces the other such that the hook members are capable of engaging the downwardly facing surfaces of the frame members, wherein each hook members includes an arm portion and defines a slot extending lengthwise along said arm portion; characterized in that the mounting bracket assembly further comprises a pair of wedge members capable of extending through the slots to thereby secure the hook members in engagement with the downwardly facing surfaces of the frame members, wherein the mounting bracket assembly is structured such that when the wedge members are extended through the slots, the respective upper ends of the slots ride up on the angled edge of the wedge members, as the hook portions of the hook members are urged upwardly toward and into contact with the downwardly facing surface of a respective frame member of the trench-forming assembly, wherein the arm portions extend at least partially through a respective aperture defined by the mounting bracket and are disposed at an acute angle relative to the mounting bracket directed away from the respective frame member, such that the hook portions of the hook members move towards each other as the wedge members are extended through the slots.