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Prefabricated construction is one of the development directions of green construction in China. Its characteristics of fast construction speed and low energy consumption can promote the rapid development of prefabricated buildings. This paper compares the development of prefabricated components at home and abroad. Through literature review and questionnaire survey, five main factors restricting the development of prefabricated buildings are determined. After that, with the government and the market as the main body, the paper puts forward countermeasures to promote the development of prefabricated buildings from demand, technology, cost and other aspects.

Rooftops provide accessible locations for solar energy installations. While rooftop solar arrays can offset inbuilding electricity needs, they may also stress electric grid operations. Here we present an analysis of net electricity generation potential from distributed rooftop solar in Los Angeles. We integrate spatial and temporal data for property-level electricity demands, rooftop solar generation potential, and grid capacity constraints to estimate the potential for solar to meet on-site demands and supply net exports to the electric grid. In the study area with 1.2 million parcels, rooftop solar could meet 7200 Gigawatt Hours (GWh) of on-site building demands (~29% of demand). Overall potential net generation is negative, meaning buildings use more electricity than they can produce. Yet, cumulative net export potential from solar to grid circuits is 16,400 GWh. Current policies that regulate solar array interconnection to the grid result in unutilized solar power output of 1700 MW. Lowerincome and at-risk communities in LA have greater potential for exporting net solar generation to the grid. This potential should be recognized through investments and policy innovations. The method demonstrates the need for considering time-dependent calculations of net solar potential and offers a template for distributed renewable energy planning in cities.

Strength reduction finite element method (SRFEM) has been widely used to analyze the slope stability. Strength Reduction Factor (SRF) is yielded as the slope Factor Of Safety (FOS) when a running-though shear failure zone comes into being, in which the Plastic Element EQuivalent strain (PEEQ) is employed as the judgment of shear failure initiation in this paper. Moreover, the filed variable is set as same as SRF along the solution processing, FOS can be directly determined as the cor-responding value of field variable when the shear failure zone goes through. Three typical slopes with varying foot gradients of 26.6, 45 and 78.7 in degree are analyzed and fantastic results have been yielded, well agreeing with the Spencer’s results, when the linear Mohr-coulomb failure criterion is employed. However, during the solution process, tensile failure zone initiates at the slope top while the plastic failure zone initiates at the slope toe and this indicates that the failure mode of slope is combined. The results show that the combined failure zone with plastic failure and tensile failure appears much earlier than the unique plastic failure zone, which indicates that the traditional analytic method and SRFEM based on the unique linear Mohr-coulomb plasticity criteria overestimated the slope stability factor.

School buildings are significant energy consumers. They are important targets for energy efficiency improvements, which can reduce energy spending and meet energy policy goals for state and federal governments. In the US, few studies have quantified electricity and natural gas consumption patterns in schools. Such information vitally supports energy planning and benchmarking. We present an analysis of high-detail electricity and natural gas consumption for schools in Los Angeles County over an extended period of time. Using a robust database of monthly account-level consumption, we examine electricity and natural gas consumption trends for hundreds of schools in relation to key structural and categorical characteristics, including size, geography, and school type. Results show that school energy use varies greatly across socio-demographic, structural, and climate factors. Correlations between electricity and natural gas consumption are time dependent and seasonally distinct. The analysis provides a useful case study with benchmarks for US public schools and demonstrates challenges with devising large-scale studies of school energy use. We conclude with a discussion of policy implications.