There is disclosed a modular platform assembly including a plurality of legs (18), a plurality of floor beams (20a,b,c), and a plurality of connectors (24a,b,c,d) for connecting the legs (18) and the floor beams (20a,b,c). Each said connector (24a,b,c,d) comprises: a downwardly open blind recess (59) with a closed top end (60) and an open bottom end (62); and an upwardly open blind recess (64) with a closed bottom end (66) and an open top end (68). The legs (18) are mounted into the downwardly open blind recesses (59) of the connectors (24a,b,c,d) and the floor beams (20a,b,c) are mounted into the upwardly open blind recesses (64) of the connectors (24a,b,c,d) such that the legs (18) extend downwardly from the floor beams (20a,b,c).

A first beam (1) is inserted through a transverse opening (4) in a tubular second beam (2). A bolt (7) is inserted through unthreaded holes (9A, 9B) in the second beam. The bolt may be transverse to both beams. A wedge (5) is threaded onto the bolt inside the second beam (2). Tightening the bolt moves the wedge against a side of the first beam, forcing it against surfaces (11, 12, 13) of the transverse opening (4) opposite the wedge. The bolt counters the reaction to this force. The beams can be formed as extrusions. The joint only requires machining for the transverse opening (4) and smoothbore bolt holes (9A, 9B) for a single bolt. The second beam may have a rectangular cross section with relatively thicker corners (2A-2D) and thinner mid-walls (2E-2H).

A sound abatement system and method providing for assembly of stacked acoustic suppression walls is disclosed. The system incorporates vertical support members (VSM) and/or vertical I-beams (VIB) driven into the ground that support an acoustic suppression panel (ACP) array by virtue of diagonal fastening cables (DFC). The DFC in one preferred embodiment utilizes a combination of threaded J-hooks, cable loops, and angle iron to fix the ACP to the VSM/VIB by frictional contact.

A coupler device (10), for connecting two overlapping building elements (V, H) at substantially right angles. The device includes a main body (11) and two hingedly attached gate elements (12, 13) extending at perpendicular and offset axes from the body. Each gate element respectively includes an associated tightening mechanism, e.g. a rod (17, 20) with threaded end engaging with a nut (19, 22), for controlling closing force toward the main body and clamping a building element. In use, the respective tightening mechanisms (e.g. nuts on threaded rod) are accessible from substantially the same direction relative to the main body and not obscured by the two overlapping building elements when fixed in place. This may be achieved by the gates, compared to each other, having a reversed configuration of tightening mechanism extending between a distal end of the gate relative to a connection point on the main body.