In order to better study the creep deformation characteristics of rock under different stresses, the generalized Burgers model was used as the basic model after analyzing the creep characteristics of rock and its relationship with stress and strain, and its application scope was verified. Based on the damage mechanics theory, a viscoplastic body considering aging damage was established, which was connected with the generalized Burgers model in series. A new nonlinear creep constitutive model was obtained, which was extended to three dimensions. In addition, the relationship between model parameters and damage variables was established by introducing damage variables that considered damage effects. The unsteady creep constitutive model of rock is obtained, and the correctness and rationality of the model are verified by test data. The results show that this model not only accurately reflects the creep characteristics of attenuation and steady creep stage but also overcomes the defect that the generalized Burgers model is difficult to describe the accelerated creep. Considering the deterioration of creep parameters with time, the creep damage process of rock under different stress states can be better described, which provides a new idea for establishing unsteady creep model and determining model parameters.

The East Tianshan contains many late Paleozoic magmatism and polymetallic deposits, and recent studies demonstrate that the Early Paleozoic volcanic rocks were discovered in the northern region of East Tianshan, which are subdivided into the Daliugou, Hongliuxia, and Kalatag formations. Here, we report zircon U–Pb ages of volcanic rocks and quartz diorite porphyry, and whole‐rock geochemical and Sr–Nd isotope data of Early Paleozoic volcanic rocks in order to investigate its petrogenesis and geodynamic setting. Zircon U–Pb analyses of the rocks suggest that the Kalatag Formation formed at ca. 438–413 Ma. Geochemical characteristics of the Early Paleozoic volcanic rocks exhibit typical subduction‐related features. They have high Mg# (44–75), positive εNd(t) values (0.25–7.88), low 87Sr/86Sr ratios (0.70457 to 0.70588), and young two‐stage Hf isotope model ages (446–551 Ma), consistent with a depleted mantle origin with limited crustal contamination. The basaltic andesite and andesite have relatively high MgO contents (6.1–9.4 wt%), suggesting that they belong to high‐magnesian andesites. They were most likely derived from the partial melting of mantle peridotite caused by the addition of fluids released by subducted oceanic slab. Based on regional geology, geochemical characteristics, and previous studies, we infer that the southward subduction of the Junggar Ocean slab resulted in the generation of Early Paleozoic volcanic rocks and arc setting‐related metallogenic systems in the Kalatag area.

In the Qinghai-Tibet Plateau, fractures and fault zones have developed in this area, where earthquakes and extreme rainfall frequently induce debris flow disasters, which seriously threaten the safety of the people and properties. In this study, Zhujiagou, Minxian County, Gansu Province in China, has a typical debris flow channel in a small watershed on the northeastern edge of the Qinghai-Tibet Plateau, which has been used as the case study for risk assessment. A debris flow-risk assessment method has been developed in this study. The fusion algorithm of entropy weight and coefficient of variation has been used to evaluate the susceptibility of debris flow in each tributary channel in the watershed. Further, numerical simulation of the debris flow events at the main channel and at the high-prone debris flow tributary channel has been carried out. The “7.18” Zhujiagou debris flow event has been used to verify that the accuracy of the numerical simulation is higher than 74.12%. This method has been applied to design the Zhujiagou debris flow-risk zoning under extreme rainfall conditions, aimed at forming a set of debris flow-risk evaluation system suitable for this type of small watershed. The results show that the peak single-width clear water flow at the mouth of the channel, the length of the channel, and the shallow surface rock formation are the main factors influencing the susceptibility of debris flow. The main tributaries of the watershed are Hagu channel, Zhuling channel, Songshu channel, and Langjia channel which are all high-prone debris flow channels. The Zhujiagou debris flow accumulation fan under the designed 1% rainfall frequency will block the Taohe, which will threaten the safety of the residents and properties near the channel, at the mouth of the channel and in the urban area on the opposite bank of the Taohe. Compared with Hagugou, Zhulinggou, and Songshugou, the low-risk area is Langjiagou. The research results of this study can be used for evaluation methods and as a basis for preventing debris flow disasters on the northeastern edge of the Qinghai-Tibet Plateau.