The static load testing rig is a device used for static bending tests on railway bridges. Currently in use, Static Load Test Bench Most test beams are composed of upper and lower girders, with vertical tie-rod mounting holes provided at each end of every girder; the vertical tie rods must pass through the flanges of the test beam to complete the connection between the upper and lower girders. Test beams with different cross-sectional shapes require correspondingly different girders. Some static-load testing rigs are equipped with balancing bases beneath the bridge bearings, each balancing base supporting two reaction legs fitted with levers. The two reaction legs extend outward from the balancing base at their respective ends; the end farther from the bridge center is fitted with a load-transmission rod serving as the loading point, while the end closer to the bridge center is hinged to a balancing pad that bears the reaction force. A problem with this arrangement is that the balancing base is provided with mounting holes that match the reaction legs, and the reaction legs pass through these holes and are hinged to the balancing base. This articulated-lever configuration can generate lateral components of force during testing, causing the reaction legs to shift and resulting in significant errors and inaccurate load readings. Furthermore, the upper and lower girders of many static-load testing rigs are not suitable for conducting static-load tests on test beams with various cross-sectional shapes.

　　To address the shortcomings of existing technologies, technicians have developed a self-balancing system for experimental beams that requires no openings and delivers accurate loading forces. Static Load Test Bench To achieve the aforementioned objectives, the invention adopts the following technical solution: the static load testing rig comprises two laterally parallel end girders and two longitudinally parallel reaction girders. Under each end girder are provided two reaction lever mechanisms; each reaction lever mechanism includes a lever beam and at least one vertical tension rod. The first end of the lever beam is supported by a reaction support, while its second end is supported by an end support; the first end of the lever beam is connected to the lower end of the vertical tension rod. The two end girders are equipped, at corresponding locations, with at least three pairs of reaction girder mounting positions, with both ends of each reaction girder being mounted on a respective pair of such mounting positions.

　　Specifically, the reaction beam is a box girder, a truss, or a composite structure combining girders and trusses. When configured as a truss, it comprises two upper longitudinal girders and two lower longitudinal girders that define the four parallel sides of the truss; multiple transverse top girders arranged between the two lower longitudinal girders for connecting jacks; and multiple longitudinal girder bracings that connect the side members to provide structural stability. Each reaction beam is installed with two pairs of lug plates, the center-to-center distance between the two pairs of lug plates being equal to the center-to-center distance between the two lower longitudinal girders of the reaction beam; one end of each lower longitudinal girder is pivotally connected via a pin to one pair of lug plates.

　　Compared with the prior art, this Static Load Test Bench The advantages are as follows: 1. Through optimized design, a self-balancing closed-force system is achieved, consisting of the test beam and the static load testing frame; 2. The use of a bench-type lever-beam structure eliminates the problems associated with movable-lever designs, while also eliminating the need to drill holes in the reaction support, thereby enhancing its structural strength; 3. More than three pairs of reaction-beam mounting positions can be configured; by selecting different spacings for these mounting positions, static-load tests can be conducted on test beams with various cross-sectional dimensions, thus improving the versatility of the static-load testing frame; 4. The installation configuration ensures that, once the jack is aligned with the centerline of the test beam’s web, the lines of action of the resultant forces at both ends of the vertical tension rod coincide with the centerline of the test beam’s supports, resulting in a safe, reliable, and cost-effective solution with clear force transmission and enhanced market appeal.