Recent Work on the Design and Construction of Air Inflated Structures

AbstractOver the last few years our practice has been responsible for the structural design of a number of lightweight structures that achieve their structural stability by inflating elements of fabric structure. The paper will explain the design rationale of key examples; describing the structural forms, methods of analysis and design, and the detailing, materials, and methods of fabrication. The largest and most complex of these structures to date is a demountable stage set structure for the Cirque du Soleil “Toruk: First Flight” show, comprising two 15 metre high and 20 metre wide structures. The stage set structures form ‘trees’ on which acrobats climb and perform. Each structure incorporates a high level access gantry with acrobat suspension and counterweight systems, as well as a secondary inflatable skin cladding. The entire primary structure and cladding system is constructed from inflated fabric elements using internal pressures ranging from 0.5 KN/m2 up to 90 KN/m2, and are deflated down to less than 5% of their erected volume for transport between venues. Other examples of our work described will include temporary pavilions with clear spans of up to 25 metres, using a combination of air tight and air permeable elements. Also a range of wide span structures that we describe as “semi-permanent” that are capable of resisting full environmental wind and snow loading, and that are fully demountable but that can also be erected for extended periods of time in a single location

The 20 most encountered InterPro accessions present in two <i>Hemideina</i> transcriptomes.

<p>The 20 most encountered InterPro accessions present in two <i>Hemideina</i> transcriptomes.</p

Positive selection within <i>Acp3</i>.

<p>Red line represents the mean posterior omega, and the blue line represents the probability of each codon being under positive selection. The values were calculated using a Bayes Empirical Bayes analysis under the M8 site-specific model in Paml. Codon position based on full-length alignment. The annotations identified using InterProScan and the position of the 24 bp indel are shown in relation to codon position.</p

Distribution of biological function annotation of two <i>Hemideina</i> transcriptomes.

<p>Green bars: <i>H</i>. <i>crassidens</i> and blue bars: <i>H</i>. <i>thoracica</i>.</p

Summary statistics of intra-specific sequence variation within three <i>Hemideina</i> species.

<p>Summary statistics of intra-specific sequence variation within three <i>Hemideina</i> species.</p

Likelihood ratio tests of positive section using PAML site-specific models.

<p>Likelihood ratio tests of positive section using PAML site-specific models.</p

Maximum likelihood phylogeny constructed using mitochondrial cytochrome oxidase subunit I (<i>COI)</i> DNA sequences from individuals representing three <i>Hemideina</i> and one <i>Deinacrida</i> species.

<p>Bootstrap support values greater than 0.5 are indicated. Scale bar represents the number of substitutions per site.</p

Candidate genes for downstream evolutionary analysis.

<p>Candidate genes for downstream evolutionary analysis.</p

Tajima’s D test results for three <i>Hemideina</i> gene <i>datasets</i>.

<p>Tajima’s D test results for three <i>Hemideina</i> gene <i>datasets</i>.</p