نشریه عمران و پروژه
سال دوم شماره 2 (پیاپی 12، اردیبهشت 1399)

The purpose of this research is to investigate the methods of excavation and the use of guard structures in residential construction in comparison with the existing standards in Tehran. The research method is descriptive-survey and of applied type. A library research tool and a researcher-made questionnaire are closed responses with Likert scale. In order to observe the validity of the questionnaire, in addition to the opinions of the supervisor and consultant professors, the validity of the factor analysis has also been used. To test the reliability of the research tool, the Cronbach's alpha test has been used, which is 0.831. The statistical population is all managers and engineers employed in construction companies in Tehran, randomly clustered 384 people. Descriptive statistics and inferential statistics including t test were used. Based on the calculations done, it can be concluded that the assumption of the research that "the methods of excavation and methods of using guard structures in residential construction are in accordance with the standard" is accepted with 95% confidence.

The country's climate and water resources indicate a serious limitation of water resources, with more than two-thirds of the country's dry, semi-arid and desert areas being the main centers and population centers, including the country's metropolises, whose water supply resources rely on groundwater. It is located in less than a third of the country in other climates with humid and semi-humid climates. Therefore, the country's groundwater resources are currently in crisis due to over-harvesting due to the increase in unauthorized wells and overdrafts of authorized wells, along with the occurrence of consecutive droughts. Groundwater is one of the most important and main water resources in In addition to providing drinking water, agriculture and industry, the country plays an important role in the country's economic prosperity. In this study, the laws governing Iran's groundwater are examined and legal avenues are provided to rehabilitate canals, abandoned and barren wells, and so on.

Civil projects is one of the leading industry sectors that spurred economic growth. Risk management and its evaluation are keys to the success of projects. Since risk is a part of any project connot be could denied. But, its proper management can offer solutions to control it. We identify the risks in the arark-khoramabad freeway project using the PMBOK. In this study, total of 16 possible risks were identified through a comprehensive literature review and field study by experts. More ever, there 16 risks were clustered into 4 components; 1) Technical, functional and qualitative risk 2) Organizational risk 3) Management risk 4) External risk. Applying expert opinions and the Best-Worst Method (BWM) that is a multi-criteria decision-making method, the relative importance (weights) of these criteria were calculated. The result show that management risk is most important criterion. The lack of financial sources and government supports are the main sub criterion and risks. Finally, with detected risk ranked, reaction programs to important risk were provided and enables the project manager and authorities to keep face of risks.

Human resource efficiency is an important concern of modern organizations; because it is considered as the most basic stimulus to achieve desired results and promote competition. Improving the efficiency of human resources in any organization requires investment, or in other words, the ways to use various types of capital to increase efficiency, and recognizing any type of capital in order to improve the efficiency of human resources is necessary. Therefore, the present study aimed at presenting the causal model of human capital efficiency in civil projects based on social capital and knowledge sharing. The applied objective of the present study and the data collection procedure is descriptive and correlational. The participants of the present study included the 300 hundred employees of Shiraz Municipality's Deputy for Civil Engineering. Sampling method in groups and sample volume through Cochran formula 168 was identified. A standard questionnaire was used for data collection procedure and measuring the research variables. The content validity of the measuring instrument was confirmed and its reliability was confirmed by Cronbach's alpha coefficient. Lisrel software was used to analyze the data. The results of path analysis showed that the dimensions of social capital have a significant effect on the efficiency of human capital in civil projects .the results also showed that knowledge sharing played a significant role in social capital and efficiency of human capital in civil projects.

Today, the use of high strength concrete in large projects around the world has become very common. It is almost impossible to build the world's largest and tallest structures without using high strength concrete technology. On the other hand, due to the wide range of concrete structures in our country, the regulations for the design of concrete structures do not mention the effects of concrete strength on the dynamic performance of the structure; Therefore, the aim of this study is to investigate the seismic performance of concrete structure with common and high strength concrete by using nonlinear dynamic time history analysis, so that the effect of parameters such as roof displacement, base shear, and axial force of the columns is compared. Therefore, at first, 2-storey concrete moment frame structure with intermediate ductility was designed in three-dimensional mode, according to the available regulations, then the real details were modeled in ABAQUS software. In order to perform nonlinear analysis, nonlinear model is used for structural elements and seismic analysis of the system is performed using three near-fault pairs of accelograms. The results show that increasing the strength of the concrete increasing the base shear as well as the stiffness of the stories, and the axial force values of the columns is almost ineffective.

Construction projects can mainly achieve the desired level of perfection by using different approaches. Assuming the conventional approach to project management is to face a systematic and predictable world. However, features such as the large number of components, the interdependence between them, the high degree of synergy, the variety of components and most importantly, the nonlinear behavior that is a key feature of complex systems, has made the nature of construction projects, It looks completely different than before. Therefore, the present study was conducted with the aim of influencing stress management and time management on the success of project management in the construction industry. The present study is a descriptive correlation from the perspective of applied purpose and from the perspective of data collection method. The statistical population of the present study of the staff of Isfahan Municipality Civil Organization was considered to be 135 people, the sampling method was determined as a group (random class) and the sample size was determined by Cochran's formula as 100. A standard questionnaire was used to collect the desired information and measure the research variables. The validity of the measurement tool is confirmed by its content and its reliability is confirmed by Cronbach's alpha coefficient. Software (SPSS 24) was used to analyze the data. The results showed that time management with a path coefficient of 0.945 has the greatest impact on project management.