Abstract: A cut-and-cover concrete tunnel structure (10) is provided with a lower concrete part (2) and an upper concrete or steel part (3) of the structure. The lower part (2) of the structure is constructed in unreinforced concrete, poured directly against and supported by a partly horizontal, partly inclined and approximately circular or elliptically shaped excavation surface (6?). The upper part (3) is arch shaped, constructed in reinforced (cast-in-place or precast) concrete or steel, and is of circular, elliptical or partly elliptical shape. This cut-and-cover structure allows a more efficient and less costly tunnel construction.

Abstract: An overfilled arch bridge system includes a composite arch which has a precast layer and a cast-in-place layer. The system further includes means for reducing bending moments within the overfilled arch. The means include customizing the arch end geometry and prestressing the arch prior to or during loading. The system can be used in connection with the overfilled arch system disclosed in co-pending patent application titled “Top Arch Overfilled System” filed by the same inventor on Mar. 22, 2002.

Abstract: A hybrid arched overfilled structure includes a combination of pre-cast side elements and at least one cast-in-place crown sector element. The side elements are pre-cast generally in a horizontal orientation and subsequently lifted into place. The crown sector element is cast in place between the side elements. In one form of the invention, each of the three sections makes up about one-third of the overall arch span.

Abstract: The top arch overfilled system defined in application Ser. No. 10/102,921 is formed of precast arch elements which are formed and shipped in a use orientation. The precast arch elements can include arch footings and the system can include a plurality of precast arch elements which can be tied together. The arch elements can also be prestressed.

Abstract: An earth overfilled arched structure includes a shallow arch spanning a clear space. The sides of the clear space are formed by curved or straight walls. Solidified zones of earth material (backfill or in situ) against the springs of the arch and/or behind the walls form foundation blocks which are in intimate contact via arch footings with the springs of the arch and/or with the upper part of the sidewalls in such a way that the arched structure delivers most or all of its support forces into the foundation blocks. These, due to their size and weight, transfer and spread the support forces to the subsoil so that displacements, especially in the horizontal directions, are minimal.

Abstract: An earth overfilled arched structure includes a shallow arch spanning a clear space. The sides of the clear space are formed by curved or straight walls. Solidified zones of earth material (backfill or in situ) against the springs of the arch and/or behind the walls form foundation blocks which are in intimate contact via arch footings with the springs of the arch and/or with the upper part of the sidewalls in such a way that the arched structure delivers most or all of its support forces into the foundation blocks. These, due to their size and weight, transfer and spread the support forces to the subsoil so that displacements, especially in the horizontal directions, are minimal.

Abstract: An earth overfilled arched structure includes a shallow arch spanning a clear space. The sides of the clear space are formed by curved or straight walls. Solidified zones of earth material (backfill or in situ) against the springs of the arch and/or behind the walls form foundation blocks which are in intimate contact via arch footings with the springs of the arch and/or with the upper part of the sidewalls in such a way that the arched structure delivers most or all of its support forces into the foundation blocks. These, due to their size and weight, transfer and spread the support forces to the subsoil so that displacements, especially in the horizontal directions, are minimal.

Abstract: A hybrid arched overfilled structure includes a combination of pre-cast side elements and at least one cast-in-place crown sector element. The side elements are pre-cast generally in a horizontal orientation and subsequently lifted into place. The crown sector element is cast in place between the side elements. In one form of the invention, each of the three sections makes up about one-third of the overall arch span.

Abstract: A hybrid arched overfilled structure includes a combination of pre-cast side elements and at least one cast-in-place crown sector element. The side elements are pre-cast generally in a horizontal orientation and subsequently lifted into place. The crown sector element is cast in place between the side elements. In one form of the invention, each of the three sections makes up about one-third of the overall arch span.

Abstract: An overfilled, pre-cast reinforced concrete arch bridge for supporting one pathway above a second pathway in which the projections of the pathways intersect at an oblique angle. The bridge includes a plurality of identically shaped arch elements that are offset from each other to form a staggered orientation whereby a skewed bridge is formed without specially shaped arch elements. Cover elements can be used to prevent migration of soil or water into the bridge and various forms of arch elements can be used in the bridge.

Abstract: A tunnelling machine for large cross-section tunnels (with a 12 m diameter and more), as well as for excavating loose rocks leading to groundwater, has a shield with a cylindrical case. A front section (1) of the case is rotary. The front face (3) of the rotary section is designed at least outside a central area (11) as a helical heading supporting surface at least approximately full when seen in the axial direction (6) of the tunnel. Preferably, the supporting surface is composed of several helical surfaces (4, 5) that supplement each other in the circumferential and/or radial directions. In the supporting surface is arranged at least one excavating shoulder (12, 13) whose surface is at an angle with respect to the supporting surface. An excavating device is preferably arranged on at least one excavating shoulder (12, 13). In the area of the supporting surface the earth or rocks are supported at the same time as they are excavated exclusively at the excavating shoulder(s).

Abstract: The front wall of an overfilled reinforced concrete arch is built from two prefabricated reinforced concrete elements, that are connected in the center by an on-site cast joint, which transmit the vertical loads acting upon them only to the foundation of the underpass, while the horizontal loads, brought about by the earth pressure from the overfill, are transmitted only at the outer edges to the wing wall and to the arch foundation, on one hand, and on the other hand to the arch from the apex portion. In the apex portion, these forces are transmitted from the front wall to the arch by means of metal rods, that transmit only horizontal stresses.

Abstract: An arch is formed of prefabricated reinforced concrete shells connected at the arch apex by an on-site cast concrete joint is built as a skewed underpass structure. In order to avoid complicated edge elements or a costly lengthening of the underpass, the individual reinforced concrete shells are formed to have their horizontal projection (in the horizontal projection of an assembled underpass) define a parallelogram which includes at least one acute angle which correspond to the acute angle formed by the intersection of the axis of the overpass traffic route with the axis of the underpass traffic route. Thus, edge elements are not necessary. An apex joint is formed of on-site cast concrete. Reinforcement rods extend into the apex joint and are arranged in an asymmetrical manner so that all elements can be designed and reinforced in the same manner with the reinforcement rods in the joint meeting directly.

Abstract: A method of recuperating heat in the partial range of the solar radiation spectrum including the step of mixing variously colored organic pigments into a fluid circulated through a hollow body, said fluid further including an antifreezing medium which is non-corrosive to the hollow body.

Abstract: A method of electroplating a crack-free hard chromium deposit comprises having present in the electroplating bath a complex halogen-containing compound which disassociates in an aqueous solution while maintaining the bond of a halogen in the complex. A plating voltage is used which periodically superimposes high voltage pulses on the base voltage.