1.The utility model relates to the technical field of bridge construction, specifically a steel girder assembling pre-arch degree adjustment device. BACKGROUND TECHNOLOGY: 2. With the rapid development of the construction market, the construction of highways, high-speed railways and other projects has also ushered in a new peak of development.

The present invention relates to a composite machining method for micro-components and falls within the field of mechanical processing technology. Background: Micro-components are characterised by their small size, thin walls, thin sheets and micro-holes.

The present invention relates to ships, and in particular relates to a method of modifying the structure of a ship. BACKGROUND TECHNOLOGY: 1. The hull structure needs to be modified during the construction of a ship, and it is common to divide a modification area in the hull and remove the original structure in the modification area