Badania naukowe dowodzą, że w przeszłości umiejętnie wykorzystywano w budownictwie zalety konstrukcyjne drewna. Ale do naszych czasów nie dochowały się drewniane kopuły starsze niż z XVI wieku, ze względu na stosunkowo dużą łatwopalność i małą odporność biologiczną. Dopiero w ostatnim wieku obserwuje się ich rozwój wskutek opanowania produkcji drewna klejonego, połączeń mechanicznych oraz zabezpieczenia przeciwogniowego i przeciw korozji biologicznej.
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Scientific studies show that skilful use was made in the past of the structural advantages of wood in building. Today, however, there are no surviving wooden domes from earlier than the 16th century, owing to the material's relatively high flammability and poor biological resistance. Only in the past century has the development of such structures been observed, as a result of mastery of the production of laminated wood, mechanical joints and means of protection against fire and biological corrosion.
W pracy zaprezentowano oryginalne rozwiązania uniwersalnych struktur kratownicowych, nadających się na podparcia sklepień o założeniu centralnym. Koncepcja konstrukcji zrodziła się z potrzeby konserwacji i napraw sklepień, które zaprojektował włoski architekt P. Ferrari i nadzorował ich budowę w Wielkopolsce. Dla sześciu form geometryczno-konstrukcyjnych sklepień wytypowano w nich punkty podparcia, które posłużyły do ustalenia topologii siatek kratownic, uwzględniając ich geometryczną niezmienność. Podano trzy grupy struktur w zależności od potrzeby podparcia fragmentów sklepień. Wskazano rozwiązania techniczne punktów podparcia oraz możliwość jednoczesnego umieszczenia rusztowań personalnych. Uniwersalność konstrukcji pozwoli na zastosowanie ich do innych sklepień oraz kopuł o podobnych formach geometrycznych. Rozwój podanych koncepcji uzależniono od doświadczeń remontowych firm specjalistycznych, które zastosują podane propozycje struktur.
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In the work it was presented 3 types of universal rod structures using to support vaultings arched with four-side and eight-side abutment. In setting of typology of rod structures it was imperfed a minimal number of rods in a bow performing geometrical Constance; tautness all proposal supporting structures is able to increase by adding aditional rods.
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In ancient Greece the conviction about the ideal order of the universe stirred interest in geometry. The quest for ideal proportions led (i. a. thanks to observations of Nature, including the human body) to the creation of so-called canons in architecture and sculpture. In this respect the Greeks regarded as ideal all regular figures (primarily the circle and the square) as well as the sphere and regular polyhedrons. They devised the perfect, in their opinion, proportions of geometrical figures, such as the rectangle based on the so-called golden division. The practical Romans developed the technology of building roofs and domes, thus implementing the Greek ideal by creating centrally planned buildings, raised primarily for ideological and prestige reasons. The domes were a synonym of the heavenly vault, and stirred human imagination. During the Hellenistic period Greek colonisation encompassed the terrains of the later Eastern Empire - Byzantium, whose culture, including language, remained to a considerable degree under the impact of Greek tradition. In architecture, the new spirit of Christianity, permeating all spheres of Byzantine culture, obtained a "Greek" form - a church raised on the central plan of a Greek (i. e. an isosceles) cross, covered with a dome on the crossing of the naves. Up to this day, the Hagia Sophia, built in Constantinople, is recognised as one of the greatest masterpieces of world architecture. In north-western Italy, which remained under Byzantine influence, the sixth century witnessed the emergence of excellent examples of edifices of this sort (Ravenna, and subsequently Venice), which affected the development of European architecture. This model was revived during the period of Mannerism, i. a. in Poland, as illustrated by the collegiate church in Klimontów near Kielce. In Aquitaine, which retained contacts with Venice, the Roman style was used for the construction of several score so-called dome churches, preserved up to this day. The Renaissance in architecture denoted simultaneously a renascence of central buildings and domes. An example of an ideal centrally designed building is the Tempietto of San Pietro in Montorio (1502) in Rome, which D. Bramante intentionally granted the shape of an ancient Vesta temple. New structure of architectural forms and technologies of building domes did not appear until the twentieth century as a result of the invention of a new material, reinforced concrete.
The two-semester division of an academic year was reintroduced in the academic year 1997/98 at all faculties of Politechnika Świętokrzyska (Holy Cross Polytechnic) after a four-year-long experiment consisting in a trimestrial system of the first-year student education. This was the reason why the author taught the first-semester students at the Faculty of Civil Engineering basics of descriptive geometry according to the changed syllabus. The aim of this paper is to open a course syllabus and its realisation for an evaluation by specialists’ forum. In particular it relates to selecting and formulating developed catchwords for lectures and exercises as well as their methodical and organisational realisation.
In this work the topology of networks is presented of chosen polyhedrons generated by transformations from icosahedron. Thę ideas of the polyhedron and spherical network are introduced interchangeably because of the identity of polyhedron vertices and truss joints of the spherical network. Each of obtained networks is treated as a full one-layer structure. Then two one-layer networks are placed and nodes are properly connected and as the result the full two-layer structure is produced. In the Table I are placed the calculated spherical co-ordinates of nodes, necessary for further computation [4].
By dividing each side of the equilateral triangle being a face of a regular 20-hedron tnto f parts and clipping parting lines as in fig. l, wo get semi-regular 80-and 240-hedrons. Vertices of the two polyhedrons lie on the concentric sphere. Rectilinear sides of the lattice, i.e. the polyhedron's sides, form the broken line of chords replacing the sphere's circles. The given geometrical parameters and the topology of each polyhedron's lattice (see frg. 2 and 3) can be used in designing one-layerb ar space structures,e .g. cupolas. Two such lattices (as shown in fig. 4) may be connected in a way presented in fig. 5 to form a two-layer space strucfure.
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