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In order to evaluate the mechanical condition and working performance of a rigid frame bridge after reconstruction and extension, the mechanical performance of the bridge was analyzed by static load test. Static load test is the test of stress at each section of main beam under the action of partial load and medium load. The results show that, under the action of each load, the check coefficient of strain and deflection at each measuring point of the box girder does not exceed the standard limit value 1, the relative residual strain or deformation at each measuring point does not exceed the standard limit value 20%, the stress condition of the tested section of the box girder is normal, and the structure is under the normal stress state under the action of the test load.

In order to evaluate the stress state and working performance of a rigid frame bridge after reconstruction and extension, load test and transverse load distribution were carried out. Static load test is the test of stress at each section of main beam under the action of partial load and medium load. Dynamic load test is used to test the inherent fundamental frequency, damping ratio and impact coefficient of the bridge through pulsation test and sports car test. The results show that the first order vibration of the bridge is mainly transverse vibration from the measured modal parameters, which is consistent with the characteristics of higher pier and greater flexibility. The vibration characteristics of the bridge structure are low frequency and small damping vibration, the value of which belongs to the normal range among similar bridge structures, the overall stiffness of the bridge structure is normal, and the measured impact coefficient during the test of sports car is less than the design impact coefficient, indicating that the dynamic stiffness of the bridge meets the design and specification requirements.

Pain in the thyroid gland is rarely present in Graves’ disease. We describe a 32-year-old female hyperthyroid Graves’ disease patient with an initial manifestation of painful goiter. On physical examination, the thyroid gland was diffusely enlarged and tender. The laboratory examinations showed high serum thyroid hormone and low thyrotropin values. Serum inflammatory markers, including C-reactive protein and erythrocyte sedimentation rate, were elevated. Thyroid ultrasound revealed multiple focal hypoechoic areas. All these findings gave an initial impression of an acute inflammatory and destructive process in the thyroid gland. However, subsequent thyroid scintigraphy demonstrated a diffuse radioactive iodide uptake pattern with positive serum thyrotropin receptor antibodies. Fine-needle aspiration cytology showed only the presence of lymphocytes. She was diagnosed as having Graves’ disease and was treated with propylthiouracil, and prednisolone was given for neck pain. Within a few days, the thyroid tenderness dramatically improved, and the erythrocyte sedimentation rate progressively normalized. However, follow-up thyroid function tests still showed high serum thyroid hormone levels. The possible etiologies of a painful thyroid gland in Graves’ disease will be discussed.