Hall Roof Research Articles

Numerical Analysis of Roof Wind Pressure Distribution in Renovated Historical Buildings: Preventive Protection Measures to Mitigate Typhoon Damage

Strong winds or typhoon disasters pose significant risks to historical buildings in many countries and regions. Although numerous researchers have discussed the damage caused by natural wind disasters, little attention has been paid to the potential impact of renovation and adaptive reuse strategies on the wind resistance performance of historical buildings—an avoidable human-induced factor. This study selected the representative ancestral hall building in Guangzhou, namely Lujiang Academy, for on-site investigation and Computational Fluid Dynamics (CFD) simulation analysis. It examined two renovation approaches: installing glass curtain walls around the courtyard and enclosing the top of the courtyard with a glass canopy. This study also assessed the roof wind pressure distribution in its unaltered state to evaluate the impact of different renovation strategies on roof wind load distribution. The results showed that installing glass curtain walls can effectively reduce the upward suction effect on the main hall roof, thereby improving its wind resistance performance. Conversely, enclosing the courtyard with a glass canopy may increase negative pressure on areas such as the eaves and corridor roofs, raising the risk of roof damage. This study systematically evaluated the renovation strategies for historical buildings, detailing the specific impacts of different retrofit measures on the wind resistance performance of building roofs. The methods and findings are significant not only for the renovation of ancestral hall heritage buildings in Guangzhou but also for providing practical scientific methods and technical strategies for the conservation and renovation of similar historical structures. This research demonstrates an effective approach to enhancing wind resistance and preventive protection for historical buildings.

An Investigation of a Post-tension Problem in a Conference Hall Roof

Introduction: Post-tensioning is a technique for strengthening concrete members by embedding tendons into the concrete before casting. When the concrete has acquired the desired strength, these tendons are tensioned using hydraulic jacks. This study deals with structurally analyzing and designing a 21 m × 25 m conference hall without interior columns contained within eleven stories building. Methods: The hall was located on the 9th floor. Many structural floor systems were proposed for the hall such as composite steel-concrete, waffle concrete, and post tensioned girder slab. The structural system of post-tensioned concrete girders with a top reinforced slab was chosen due to its advantages: low deflection and low risk of cracking, and increase of net floor height. Stressing of strands (live ends) was applied from the four sides of the concrete slab. Twenty-three live ends were placed in north-south direction and 20 live ends in east-west direction. Results: The ultimate strength of the stands was 1860 MPa. The jacking force, 209 kN, was applied in each strand which represented 75% of ultimate strength. The post-tension concrete slab was analyzed with Ram concept software, which revealed that the total elongation of strands in the E-W direction ranged from 116 mm to 152 mm, and the total elongation of strands in the N-S direction ranged from 120 mm to 172 mm. Conclusion: The problem of warping of nine live anchorage ends in the south-north direction was encountered during post-tensioning, which resulted in the movement of strands from their original locations. A rehabilitation plan was proposed to overcome the aforementioned problem.

Innovative design of a suspended large-span exhibition hall roof in Wuzhen, China

The 2019 Light of Internet Expo main exhibition hall in Wuzhen, China has an innovative roof system combining beam strings, multi-span suspended beams and redundant wind-resisting cables, covering an area of 90 m × 211 m. The suspended 200 mm deep beams form an undulating roof of 35.5 m to 48 m in span length. The novel design, which efficiently combines architectural aesthetics and structural force flow, needed to be completed and built in just 7 months for the exhibition. This paper focuses on structural design issues such as form finding, shape optimisation and structural analysis.

CROSS Safety Report: Collapse of unusual hybrid concrete-and-steel strand truss on school roof

This month we present a report about the collapse of a school hall roof, which resulted from the failure of one of a number of unusual hybrid concrete-and-steel strand trusses.

Soft touch temporary works: Westminster Hall roof lantern freestanding access, UK

The temporary access scaffold for refurbishing one of the Westminster Hall roof lanterns at the Palace of Westminster in London, UK, required a particularly sensitive approach. The only means of support, other than scaffold towers 38 m apart at ground level, were two awkward-shaped parapet walls. Removing the capping stones of these walls would be a health and safety risk and unsympathetic to the historic listed building. Standing over 45 m high with a main bridged span of 25 m, the scaffold was stabilised without the need for a single intrusive fixing. It was supported directly off existing parapet walls in such a way that no trace of the scaffold was left after 3 years in use.

Environmental Pressures at Dirre Sheikh Hussein Sanctuary

Dirre Sheikh Hussein is a religious complex in Ethiopia that dates from the 12th century or earlier. An important focus for pilgrimage, it lies in an isolated part of Oromia State on poorly drained semi-arid lowlands. Significant architecturally and culturally, recent expansion and refurbishment of the major buildings led to structural issues, though these are now largely overcome through consolidation of the prayer hall roof, laying a stone walkway, digging drainage ditches etc. Current deterioration of the buildings can be seen as: (i) fading of colours, (ii) cracks in walls, roofs, and festive places, (iii) deposits of sand around walls and (iv) staining and drainage marks on the white painted surfaces. Heavy falls of rain overwhelm drainage and overfill storage pools. Meteorological observations are infrequent locally, so those made some 70–100 km away were used, along with regridded historical data, reanalysis and CMIP6 projections. These revealed increases in temperature, precipitation and humidity, and provided indications of long-term climate pressures at the site. Changing patterns of future precipitation, particularly heavy rain, may threaten the site. The relative humidity changes are small, though an increasing Scheffer index suggests potentially enhanced wood decay. Changes in soil moisture have the potential to disrupt the foundations. Very hot days may become a problem for the two annual celebrations at the site.

Effects of non-uniform temperature on closure construction of spatial truss structure

Due to exposure to the natural environment, the non-uniform temperature effect of a spatial truss structure that is under construction is the main factor that causes difficulties in closure construction; thus, the construction quality and efficiency will be directly affected. The standard hall roof of the Xi'an Silk Road International Convention and Exhibition Center is selected here as the research object to study the structural non-uniform temperature effect on closure construction. The structural temperature field and effect during construction are simulated by finite element methods based on the on-site monitoring of thermal boundary parameters. During the closure construction period, the temperature distribution is significantly non-uniform. Furthermore, the non-uniform temperature effect causes the alignment deviation of welded joints, the value of which can be up to 14.3 mm. The assembly quality of members and the structural connection accuracy have difficulty meeting the requirements at most times. After forming, the structural residual stress may reach 68 MPa, and nearly 6% of members experience residual stress of over 50 MPa. Construction suggestions for the welding time and sequence are proposed according to analysis of one-month's simulation results. The research method and conclusions of this paper can provide valuable references for the closure construction of a spatial trusses or similar structures.

A posteriori modelling of a fire spreading in selected types of industrial halls

Two different scenarios of fire development identified for two industrial halls are considered and discussed in detail. In both cases an attempt is made, using the appropriate numerical models, to describe a posteriori the spread of a fire that has already occurred in the past. The numerical model is implemented in a Fire Dynamic Simulator (i.e. FDS) computer program and used for simulation. The first considered hall is an one-storey two-aisled steel structure with an incomplete covering of its side walls. Recyclable materials were stored inside, mainly the plastic waste. The fire observed in this hall developed slowly, being repeatedly partly suppressed and then subjected to flashover again. The other building described in this contribution is an one-bay steel hall located in a transhipment terminal, in which the crude oil was stored in railroad tank cars. In this case, a fire initiated by the ignition of oil leaking from the damaged tank car and quickly intensified by the collapse of a part of the hall roof proceeded rapidly until the fuel supply ran out. The basic parameters of both models developed by the authors were calibrated on the basis of available material data as well as of the reports received from meteorological stations located in the vicinity of the destroyed halls.

Performance-Based Analysis of Older-Type Large-Space Hall in Fire

AbstractThe paper presents the example of performance-based analysis for the existing large-space steel structure raised in 1980s. Hall is used as a paper products warehouse. Advanced mechanical simulations are performed using Safir software. Factors that impact the final fire resistance of the structure are discussed. Local and global imperfections and possible ways of structure modelling are taken into account. For selected cases advanced fire scenario that considers both localised fire and possibility of further ignition of stored goods is prepared using Fire Dynamics Simulation software. The results obtained indicate that added imperfections have little impact on the fire resistance of the structure and older-type steel hall roof without any fire protection could survive 30 minutes of fire. Main failure modes and values of structure’s deflections are also presented. Finally, performed simulations show that even for large-space structure the flashover is possible in some special cases.

Estimation of the composition of the forced and free vibrations of the casing of the steel rope roof of Ukraine Cinema & Concert Hall located in Kharkov over the area of main line tunnel of working metropolitan railway

The paper discusses issues related to the dynamic parameters of the metro train influence on the building construction of Ukraine Cinema & Concert Hall complicated in terms of construction located in Kharkiv City. The hall roof is of peculiar complexity made in the shape of hyperbolic paraboloid hung to the cable roof system and supported by the inclining reinforced concrete arches. Using the equipment by DIAMEX 2000 LLC we have measured vertical and horizontal forced vibrations in the most relevant points of the casing. Natural vibrations were defined by creating dynamic impact of the falling load weighing 10 kg from a height og 2 m. The vibration parameter measurement was carried out by means of Ahat-M vibration analyzer. As a result we have obtained amplitude-frequency characteristics of the forced vibrations caused by metro train movements. The frequency of base and obertones is within 30-50 Hz. At the same time, vibration amplitudes is up 200-350 pm. Specific range of vibrations leads to the occurrence of the for framing roof framing (concrete and steel strand guy ropes), noise penetrating into the hall significantly worsens operating characteristics for the spectators. A special calculation of guy rope element taking into account fatigue factors has been made.

Akhet-Aten, The City of Akhen-Aten

Akhet-Aten took four years under construction before Amen-Hoteb IV announcement that the deity is “Aten”. That was manifested in the orientation of his temple to receive the sun rise on its longitudinal central part, on January the 2nd, in the fifth year of his reign. In that moment, Amen-Hoteb IV changed his name to Akhen-Aten. Almost the same concept – to have the sunrays enter the interior- was applied to the city house design, to let the sun's rays illuminate the central hall's alter all the day; and that required to have the square house design tilted to the north and, to have the central hall's roof higher.

The Skyshine Benchmark Experiment Revisited

With the coming renaissance of nuclear power, heralded by new nuclear power plant construction in Finland, the issue of qualifying modern tools for calculation becomes prominent. Among the calculations required may be the determination of radiation levels outside the plant owing to skyshine. For example, knowledge of the degree of accuracy in the calculation of gamma skyshine through the turbine hall roof of a BWR plant is important. Modern survey programs which can calculate skyshine dose rates tend to be qualified only by verification with the results of Monte Carlo calculations. However, in the past, exacting experimental work has been performed in the field for gamma skyshine, notably the benchmark work in 1981 by Shultis and co-workers, which considered not just the open source case but also the effects of placing a concrete roof above the source enclosure. The latter case is a better reflection of reality as safety considerations nearly always require the source to be shielded in some way, usually by substantial walls but by a thinner roof. One of the tools developed since that time, which can both calculate skyshine radiation and accurately model the geometrical set-up of an experiment, is the code RANKERN, which is used by Framatome ANP and other organisations for general shielding design work. The following description concerns the use of this code to re-address the experimental results from 1981. This then provides a realistic gauge to validate, but also to set limits on, the program for future gamma skyshine applications within the applicable licensing procedures for all users of the code.

The Design of the Westminster Hall Roof

Many attempts have been made to determine how the Westminster Hall roof works, and nearly as many different conclusions have been reached (Figs 1, 3, and 4). Some architects, engineers, and architectural historians have concluded that the principal support of the roof is provided by its great wooden arch. Some have argued that the roof functions like other hammerbeam roofs, but they have not been able to agree on how a hammerbeam roof works. Still others have held that so unprecedented a space could only have been spanned with wood by combining two different types of roofs — the hammerbeam roof and the arched roof. The Westminster Hall roof is so complex that it appears as if it might function in any one of these ways, but it cannot function in more than one.

The Westminster Hall Roof: A New Archaeological Source

Abstract The recovery in recent months of the complete set of large drawings, the ‘Schedules’, made by Sir Frank Baines in preparation for his restoration of the Westminster Hall roof (1913–22) is a major archaeological document that complements Baines's published Report to Parliament (1914). In addition to a painstaking record of earlier repairs to the timberwork, the ‘Schedules’, enhanced by colour and marginal comments, expand our knowledge of the original framing of c. 1395, especially the lower region of the truss. From the combined information of the Report and now the ‘Schedules’, further insight into Herland's technological perceptions are presented, in particular, the configuration of the masonry support for this immense roof of unprecendented clear span. This paper, therefore, concentrates on the portion of the roof occupying the space between the heraldic corbels and the top of the wall—an area that has caused some recent debate with regard to the overall structure of the roof The new archaeolo...

The Westminster Hall Roof: A Historiographic and Structural Study

The great hall roof of the medieval palace at Westminster, which now adjoins the British Houses of Parliament, was erected c. 1395 by Hugh Herland and stands as one of the great achievements of English monumental carpentry. When the roof was built to span the vast un-aisled interior of nearly 68 feet, it was 50 percent wider than any previously known hall in England. Hence, this unique framing of unprecedented scale has long been regarded as a technological tour de force uniting engineering skill and visual elegance. For the last century and a half, Herland's framing, combining a great arch with a "hammer-beam" bracket, has been discussed for its remarkable structure, and a number of ideas have been suggested by English and Continental experts concerning how the great weight of the roof is sustained and which members of the truss are structural as opposed to those which are mainly decorative. Yet, despite recent analyses by prominent engineers, there is no consensus of opinion as to how the frame actually carries its load. From a review of the major literature, which forms the first part of our study, a number of important questions arise concerning the nature of the timber frame, the function of its primary members, and, particularly, the precise structural relationship between the roof and its supporting masonry. In order to address and resolve the major structural and historiographical issues, we have undertaken a new and more complete study of the Westminster roof that combines archaeological and historical research with two types of interactive model analyses. The initial model was carefully constructed of timber at 1:10 scale to conform as closely as possible to a transverse frame of Herland's truss. This model, instrumented with electric-resistance strain gauges, was used to determine the general behavior of the truss under loading and with three kinds of support conditions, corresponding to the conflicting theories examined in the literature. Using the data from the timber-model testing as a guide, we then refined the analysis with a numerical (computer) model. Our results have clearly resolved the major questions raised by previous studies and indicate that the roof derives its primary support from the masonry wall at the level of the heraldic corbels, upon which rest the massive timber wall posts. The load of the roof is carried nearly halfway down the walls by the combined action of the heavy hammer posts and the great arch rib. We also found that the angel hammer beams are in tension and that they function, significantly, to take horizontal forces off the top of the wall. Moreover, these findings are consistent both historically and structurally with other examples of English carpentry that preceded Herland's brilliant design for Westminster Hall.

The Westminster Hall Roof and Its 14th-Century Sources

The great angel roof of Westminster Hall, London, erected for Richard II in 1395-1396, remains the consummate achievement in medieval open-timber roofs. The framing, which has an exceptional single span just over 67 feet, is a multitiered construction that combines two major truss types: the hammer beam, and the arch-brace-and-collar roof. The architectural background of the Westminster Hall roof has generally been confined to precursors of the hammer beams that visually dominate the interior and are certainly a major aesthetic if not structural element. When the prominent role of the arch-brace and related decorative detail are recognized, however, a different set of prototypes emerges, principally the chapel at New College and the great hall at Windsor, whose connection with Westminster Hall is more immediate and compelling because of the documented relationships between patrons, craftsmen, and court. Finally, the interaction between late-14th-century carpentry and masonry charts a shift in stylistic values that is critical to understanding English Late Gothic.

Repair and Restoration of Assembly Hall Roof

During the early expansion of western America a group of Mormon pioneers came to the Great Salt Lake valley in covered wagons, arriving in July of 1847. Here they began to build a city. In the center of the city they established a Temple Square, on which a building called the “Assembly Hall” was built in 1877. After 100 yr of service life three of the six roof trusses failed for no apparent reason. After much study, it was determined the unique structure could be restored without destroying its artistic or historic value. Under a construction management program, a select group of experienced and skilled craftsmen completed the restoration. The unique and indeterminate roof structures had failed in the heel joints and main tensile members. The general solution was to replace the failed connections and members with steel straps and heel connections. Bob beams and structural diaphragms were constructed to upgrade the safety of the structure, all as part of the restoration. The project proceeded on time and w...

Trial excavation for underground caverns at Dinorwig power station

At the start of construction of the nine main caverns for the Dinorwig power station, a heavily instrumented trial opening of one section of the Machine Hall roof was excavated under controlled conditions as part of the overall design of the rock-support measures. Following excavation, incremental reductions in the installed support loads were made to provide data for assessing support pressures. Observations of rock-mass behaviour were compared with the results of theoretical studies. The results of the trial were used to assist in the assessment of the design of the remainder of the caverns; they enabled significant economies to be made by increasing the rate of excavation and by reducing the overall quantity of support required. Lors du commencement des travaux pour construire les neuf cavernes principales pour la centrale électrique de Dinorwig, un agrandissement d'essai, équipé d'une gamme grande d'instruments, d'une section du toit de la Salle des Générateurs comme faisant partie de l'ensemble du projet de soutènement des roches. Après l'excavation, des réductions incrémentales ont été faites par les charges de soutien installées, afin d'obtenir des données pour l'évaluation des pressions d'appui. Les observations du comportement des masses rocheuses ont été comparées avec les résultats d'études théoriques. Les résultats de l'essai ont été utilisés pour determiner les hypothèses de calcul des autres cavernes, de sorte que des économies importantes ont pu être réalisées en augmentant la vitesse d'excavation, tout en réduisant la quantité totale des appuis nécessaires.

WESTMINSTER HALL ROOF.

WESTMINSTER HALL ROOF.

The Old Deanery, Salisbury

An inspection of the Old Deanery in 1948 failed, for some reason unknown, to disclose the early date of the building. Neither the medieval form of the plan nor the antiquity of the Hall roof were recognized. In default of any clear case for preservation on archaeological grounds, and though the case on scenic grounds was very strong, the decision was made to demolish the building to make way sooner or later for the development of a Ladies' Training College, despite pleas for preservation from the Local Planning Authority and from Mr. H. de S. Shortt, Curator of the Salisbury Museum.