No abstract

As a new type of bridge foundation, rectangular closed diaphragm walls (RCDWs) provide an efficient solution to controlling the settlement of high-speed railway bridges. However, the scant research on settlement prediction for RCDWs has hindered their application in practical engineering. This paper attempts to establish a simplified approach for predicting the settlement of RCDWs. First, a simplified analytical model of an RCDW is established in accordance with the load transfer approach. Then, the load transfer curves and related coefficients of skin friction and foot resistance are discussed, and special attention is given to the determination of inner skin friction based on the results of a model test. In addition, an iterative procedure is applied to facilitate the solution process; moreover, a program named SPFRCDW, written in Matlab, is developed to estimate the settlement of RCDWs based on the proposed approach. Finally, a case study is conducted to verify the calculation results of SPFRCDW. The results predicted by the proposed method are shown to agree well with the measured data.

No abstract

A new application of the internet of things in a low-cost greenhouse with no networked intelligent control equipment.The systematic water-saving management focused over the whole growth stage of crops, and it can effectively increase yield and quality.Replace some chemical fertilizer with fully-decomposed organic fertilizer and new types of fertilizer to reduce negative impact on soil and the environment.Regarding pesticide usage, we advocate prevention first and treatment second.Improve systematic water-saving management with regard decreases in crop yield and quality.Abstract. A basic greenhouse is an inexpensive type of greenhouse, which lacks networked intelligent control equipment; it is currently the most common type of greenhouse used in China. To manage planting activities intelligently and improve water use efficiency in these greenhouses, an intelligent planting management platform for strawberry based on the internet of things (IoT) is developed. On the platform, human-computer interaction occurs through the WeChat app on a mobile phone so that manual control of the strawberry environment in the greenhouse can be conducted. In this study, we add a user module in the perception layer of the IoT to obtain the information and manually control the environment in a basic greenhouse. The network layer uses narrowband IoT wireless transmission technology based on 4G. The application layer is designed with a systematic water-saving management knowledge base for strawberry. The systematic water-saving management feature includes seven parts: strawberry variety selection, planting seedlings, flower and fruit thinning, environmental control, disease and pest prevention and treatment, fertilizer management, and water-saving irrigation. Through the human–computer interaction platform, growers can receive decision-making options, planting management evaluation, query information retrieval, and regular relevant planting information. The application results of the platform showed the following: compared with management experience of growers, the water use efficiency of yield (WUEy) increased by 128.55%, the water use efficiency of production value (WUEpy) increased by 226.31%; the amount of chemical fertilizer decreased by 40%, the amount of pesticide decreased by 61.67%, and the cost of pesticide decreased by 32.48%; thus a decrease in the use of both fertilizer and pesticide was achieved. This study can directly provide technical support for strawberry intelligent management in basic greenhouses, and can also be used as a basic platform intelligent management systems for other crops grown in basic greenhouses. Keywords: Basic greenhouse, Intelligent agriculture, Internet of things, Sensor network , Systematic water-saving management, Water-use efficiency.

No abstract

No abstract

No abstract

Geobag retaining wall using construction waste is a new flexible supporting structure, and the usage of construction waste to fill geobags can facilitate the construction recycling. In this paper, model tests were performed on geobag retaining wall using construction waste. The investigation was concentrated on the slope top settlement, the distribution characteristics of the earth pressures on retaining walls and horizontal wall displacements, and slope failure modes. The results indicated that the ultimate loads that the slope tops with retaining walls could bear were 87.5%∼125% higher than that of the slope top without retaining walls. The ultimate loading of strengthened slopes with different slope ratios from 1 : 0.75 to 1 : 0.25 could be reduced by 11.8% to 29.4%. The horizontal displacements of the retaining walls constructed from geobags were distributed in a drum shape, with the greatest horizontal displacements occurring about 1/3∼1/2 of the wall height away from the bottom of the wall. As the slope ratio increased, the failure of the slope soil supported by geobag retaining wall using construction waste changed from sliding to sliding-toppling (dominated by sliding) and then to toppling-sliding (dominated by toppling). The range of 1/3∼1/2 of wall height is the weak part of the retaining walls, which should be strengthened with certain measures during the process of design and construction.