فصلنامه جاده
سال بیست و یکم شماره 2 (پیاپی 75، تابستان 1392)

The road transport sector more important because the in Iran done the main contribution of the movement of goods and passengers by this section and efficient management and correct of activities for road transportation can accelerate the growth of this sector.
The objective of this paper is Estimate of production function in the Iran''s road transport sector using Translog production function during years of 1974-2011. The results show that if a percent Capital stock Increase¡ the value added of road transport will grow 16.86 percent. Partial elasticity of Labor is 14.26 that show increasing a percent in labor of road transport increased value added of road transport to 14.26. Another effective variable on factors of production in the Iran''s road transport sector is energy consumption that has a positive impact and the effect is 8.958 that Show increasing a percent in energy consumption of this sector¡ increased value added of road transport to 8.95.

Pavements that exposed to moisture and heavy axial loads deteriorate rapidly and are destroyed. Stripping is one of the main distresses that occur in asphalt pavements. Because of this distress mainly either resulting from moisture or dominating by moisture thus usually calls as moisture damage. This problem not only is as a distinct distress but also can cause to the other asphalt distresses such as cracking, raveling and rutting. Hydrated lime (in the amounts of 1-2%) is considered as the most important anti-stripping additive for prevention & rehabilitation of this distress in all of the literatures. The main goal of this research is studying of the stripping in asphalt mixtures. The key factors which be considered in this research are temperature and selecting suitable approach (using of hydrated lime) for control and assessment of this distress in the laboratory conditions. In this research, the aggregates of west of Tehran and the AC60-70 bitumen of Esfahan refinery are used. In this research with the aim of investigation of the effects of temperature and additives on moisture susceptibility, mixes containing various amounts of hydrated lime (0, 1, 1.5 and 2%) were prepared at two different (40 and 60 ) temperatures. The optimum binder content was obtained 6% from Marshall Method of mix design and then the effects of temperature and hydrated lime on moisture susceptibility of asphalt mixtures investigated using Wheel Tracking (AASHTO T-324) and Marshall Quotient (ASTM D-1559) tests. The results (in the dry and saturated condition at above mentioned temperatures) indicated that the addition of hydrated lime in asphalt mixes reduced the moisture susceptibility of hot mix asphalt. Also, it is shown that the use of hydrated lime at the saturated condition, results in better properties compared to the dry condition.

Bus stops are one of the most important infrastructures at bus transportation system that decreases the role near-side bus stop with regard to having it before the intersection and the effect on the traffic stream of Inter section area is very important. The purpose of this article linear Modeling for predicted to place near-side bus stop in intersections with signal control use of Survey five elected stop in Mashhad city. Number of Records has statistics for modeling; record 575 has been with the use of the analysis multiple linear regressions by SPSS 19 software. The results caused by the evaluation of proposed models coefficient of determination above 0. 9 are that this put satp orange of models. Validity proposed models with the use of the data collection of the other stop in Mashhad city which indicates the results satisfaction for predicted place near-side bus stop in intersections with signal control. As regards in our country to examine Micro Models location for the bus stops; not been paid¡ the results can be the existing problems in this section improve to some extent.

In discussion about digging tunnel and well in loose ground¡ there are methods and different machines to control special conditions for ground reinforcing. One way which has global utilization is cement grouting (cement and additive materials) for hollow places in construction. There are some elements which delay and prolong the dig such as decreasing the thickness into upper layers in tunnel project of surface parts relate to civic ground and presenting non resistant and loose mineral materials. This subject makes that digging method change abruptly. And other special methods will be used such as cement grouting by influence of cement grouting by means of cement compaction grouting to jet-grouting and etc. Selecting the correct method for rock and soil resisting depend on different conditions for example type and alternative layers of charged scale¡ mode and project type. The various kinds of cement grouting methods will be reviewed on their properties in this paper. We hope that geotechnical and mine engineering can select proper methods for improving problematic soil and solve their problems.

Since the nanoscinence is an interdisciplinary field of science¡ various industries and sciences have been influenced. The use of nanotechnology in the manufacture of new materials is increasing day by day. Due to significant influence of these additives on important the quality and properties of materials caused a significant increase in researches of this field. The main role of pavement is to persist again the detriment effects of traffic loading and climate conditions. This goal can be better achieved¡ by applying the nanotechnology in pavement engineering. This paper investigates the results of various researches about effects of three groups of nano materials consist of Sio2¡ Tio2 and Carbon nano tube on the engineering properties of cement concrete mixes that have been designed to use in pavement application. Based on obtained results. The results show that the optimum contents of nano-particles improved the mechanical properties of concrete mix such as tensile strength¡ flexural and compressive strength. Subsequently¡ the strength properties of concrete reduced with increasing the nano-particles quantity more than the optimum content.

Tunnel excavation disturbed the orientation and intensity of stress field around the tunnel. In addition¡ it becomes drainage systems that change the ground water path and decrease the water level. As a result of this¡ non-uniform pressures distribute on the lining and cause the non-uniform displacement. Water intrusion not only makes trouble in excavation process¡ but also it has many effect on tunnel lining during their working life and on other device like rail¡ electronic and mechanical device and etc. In this paper¡ damaging effects of water on ground (external effect) and tunnel lining (structural effect) was studied. Also¡ its effect during the service time (practical effect) was discussed.