Journal of Civil and Environmental Engineering

It is extremely challenging to describe the time dependent behaviour of sandstone under stress due to its homogeneity at the macro scale and heterogeneity at the macro scale. Crack initiation and progression may be affected by macro scale heterogeneity. The development of macro scale fractures is strongly influenced by crack clusters. A time-dependent damage model is presented in this paper to investigate the effect of crack evolution on the occurrence of fractures during creep deformation. Based on the elastoplastic theory of rock and the micro-heterogeneous characteristics of sandstone, the instantaneous elastoplastic damage model of sandstone was initially developed. The Nishihara model and the elastoplastic damage constitutive model were combined to create a viscoelastic plastic creep damage model. The outcomes of the corresponding analytical solutions have confirmed the proposed models. The time-dependent behaviour of sandstone was examined using conventional constant strain rate tests and multi-step creep tests to support the model. Both the time-dependent viscoelastic deformation characteristics of sandstone and the creep behaviour’s viscoelastic plastic deformation characteristics are well-represented by the proposed damage model, as demonstrated by the findings.

This study examines the government's approach to segregation through urban planning and the history of master planning in Kabul. The first of five master plans was created. The city of ethnic division was exacerbated by the civil war. The Pashtun, Tajik, and ethnic groups that live in three distinct zones make up the majority of the city's ethnic diversity. Starting with the initial master plan for Kabul in the continuing through the current urban design framework for Kabul, the urban planning literature and master plans for the city are examined. The authoritarian planning of the first three master plans was based on technical rather than communicative rationales. However, the city's ethnic segregation was abstractly addressed in the fourth master plan, which was developed through citizen involvement. In terms of participatory planning, the fifth master plan, the urban design framework, was a step backward by unequally distributing the future economic zones, administrative hubs, and facilities hubs it also ignored the city's ethnic segmentation. The city's ethnic segregation has been ignored in previous master plans the city approach to segregation through urban planning is not outlined in detail. The term divided city refers to a variety of phenomena in which cities are geographically separated according to ethnicity, race, income, and age. Social and ethnic segregation in western cities, civil war in Beirut, political division in Berlin, and intense inter communal conflict and violence as a result of ethnic or nationalist fractures all occur in an alarming number of cities.