During last years the need of knowing the forest in its various aspects, quantitative and qualitative, has enabled the appearance of a new technique forestry geomatics. Named as “the science of future” this technique integrates multiple technologies such as Remote Sensing, Airborne Photogrammetry, LIDAR, Geographic Information System (GIS), Global Positioning Systems (GPS) or classical geodetic technology for data acquisition, data processing, data analysis and data management. The purpose is to provide specific information regarding the evaluation natural forestry resources. In this paper will be presented the utilization of terrestrial 3D laser scanner and GIS technologies in forestry inventory.
In this paper, four specimens of steel beam to column joints with different configuration of bolted angle connections are experimentally tested. The specimens are double sided beam to column connections and are tested under bending loading conditions in order to investigate elastic and inelastic connection behaviour. The semi-rigid beam-to-column connections were subjected to monotonous static loading. The bolted beam-to-column connections are composed from top and seat angle connections with and without web angles as well as with stiffened top and seat angle cleats. The intent of the experimental investigations is to highlight the ability of the connections to maintain strength and to provide rotational capacity. The experimental results are evaluated with the measured force displacement data, from which the characteristic moment-rotation curves were established. The experimental results indicate the primary failure modes include member deformation. The moment-rotation relationship of the tested joints exhibits a significant inelastic nonlinear response. The paper concludes with the comparison of the tested joints in terms of strength and stiffness, highlighting the advantages and weaknesses of the studied joint typologies.
The article presents aspects related to the calculation of heat loss through the pipes of the interior central heating system. The purpose of the article is to detail the local heat losses in case of central heating systems. Based on the conclusions of the article, we propose the modification of the calculation methodology related to the building energy audit.
From the entire globe surface which is over 13.5 billion ha, the agricultural area represents more than one quarter (means 3.4 billion ha). The cultivated areas cover approximately 1.5 billion ha, which means 8% of the total lands, to each inhabitant of the planet assuming the 0.25 ha. The most agricultural space is located in the temperate zone (about 2 billion ha), which represents 55% of agricultural space world and also here lies mostly in the sown area of the planet (830 thousand ha, 59%).
An issue more and more important in construction science represents the rehabilitation of structures placed on difficult soils. This paper presents the behaviour analysis of an existing structure and summarizes several consolidation solutions at both levels of a severely damaged construction placed on a shrinking and swelling soil, located in Arad County - Romania, situated on 55 Revolutiei Avenue. These types of soils are known in specialty literature as shrinking fields, expansive or active soils, having the property to modify sensitively their entire volume when there are variations of moisture, being spread on a large scale in Romania. After the assessment of seismic safety for a section of the damaged structure, which is characterized by a high risk of collapse from seismic action, reason for which it has been proposed to immediate by consolidate the damaged construction.
Malta is a representative model for recording and preserving archaeological remains and historical monuments. Being a historically and culturally rich location, it requires creating, maintaining and updating a database in order to keep a record of the state of degradation or the actions to restore historical monuments. One way to preserve the image and shape of a historical monument is by creating a three-dimensional model. The advantage of such a model is its visualization and keeping in a form close to the real shape of a monument in a particular moment in time. It can thus highlight the levels of wear and degradation, the eventually necessary rehabilitation works or simply reproduce the impressions that the building would actually leave on a visitor.
Irina Smical, F. Filip-Văcărescu, G. Danku and V. Paşca
The recycling issues related to the construction and demolition (C&D) wastes in the sustainable development and the circular economy context represent a continuous challenge for researchers. This paper reveals the possibility to recycle the hardened mortar recovered from C&D wastes. Thus, the recovered hardened mortar with grains size less than 16 mm was used in the concrete structure. The compression resistance of the final concrete was determined using a Heckert 3000 KN testing machine and the results showed a better compressive strength for the samples with C&D waste content than the standard sample of about 1.19 times. This is a good premise for improving the researches related to C&D waste usage in concrete production.
L. Kopenetz, A. Cătărig and Mihaela Teodora Ghemiş
In the case of light structures membrane type the form is confused with the structure and vice versa. Thus the analysis process, non-linear type, the one for form finding is also a means of optimizing these structures. To respect the natural principle of minimum it is advisable that the structure’s shape is similar to the minimum surface area. The numerical problem solving is based on using finite elements with constant strain of soap film. Based on these considerations, the paper presents aspects of determining the shape of the membrane structure using finite elements of soap film.
Intended contribution emphasizes the statics and kinematics of semi-rigid steel frames seismically acted upon. The dynamic model of analyzed structures consists of multi degree of freedom systems with lumped masses located at floor levels. The dynamic degrees of freedom are the lateral seismically induced floor displacements. A cyclic behavior of semi-rigid beam – column connections associated with the four parameters analytical bending moment M – relative rotation θr is considered. Time history seismic analyses are performed on multi-story steel planar frames equipped with several top and seat and web angle beam – column connections acted upon by recorded seismic actions. The computed numerical results refer to the contrary static and effects of semi-rigidity: the increase in lateral floor displacements accompanied by a decrease in the seismic base shear force. Relevant comments are drawn.
The paper presents the results of numerical analysis on the effects of thermal bridges at wood frame buildings with or without thermal insulation placed on the exterior surface of the wall. The heat flow crossing the wooden thermal bridges, respectively the linear heat transfer coefficients ψ and the temperature factors fRsi, can be established based on the plane temperature field in stationary thermal regime. The “PSIPLAN” computer program used to determine the temperature field, derived from the original program “CIMPLAN” with its first version developed in 1980. The program allows graphic description of the plane section of a thermal bridge and discretizes automatically the section on both axes in accordance with the stipulations of the EN ISO 10211-1:1995 standard and EN ISO 10211:2007 standard. The computer program generates automatically the system of equations that is solved using iterative methods until the heat flows on the two surfaces of the section are balanced. The calculation results are presented with numerical values and in a graphical manner by isothermal surfaces. The program has various libraries that include several types of wood thermal bridges.