In recent years, the need for an accurate identification of the conditions of the earth has become apparent, in response to the growing need for larger and more deep underground spaces., underground excavations can be classified into three groups of tunnels, caverns and mines. The new township tunnels of the Pardis are part of the Phase 5, 8.9, and 11 new Pardis projects, which aim at providing access to these phases independently to the highway and the large Pardis of Tehran, and the arterial axis of the first phase of the 3.2 phase 1 and 4 new Pardis cities. The purpose of this research is to use different numerical methods for studying and analyzing the stability of Pardis tunnels in Karaj Formation using numerical methods of finite difference in continuous environment (FLAC software) and separate element in the discontinuous environment (UDEC software). In this research, the sustainability analysis of the tunnels of the Pardis was first performed and optimized by applying a variety of numerical methods. Finally, the results of different methods were compared with the results of the instrumentation. The results show that the model made by UDEC software is closer to real Earth conditions compared to the FLAC software. According to the results obtained from the comparison of the amount of displacement occurring around the drilled space, this environment has a discontinuous behavior.

The study examined the influence of cohesion, friction angle, and tunnel diameter on stability within engineering and geotechnical frameworks, while considering the consequences of nearby excavations on the overall stability assessment. The results show that a higher angle of internal friction leads to a decrease in soil stability number and weighting coefficient. Tunnel diameter significantly affects face support pressure, with larger diameters requiring stronger support due to increased stress. Higher friction angles help stabilize tunnel faces and mitigate diameter-related pressure effects. Stress redistribution around the tunnel is significant within 2 meters from the center, transitioning to elastic behavior elsewhere. A safety factor of 1.3 ensures tensile failure prevention in single and twin tunnels. Balanced stress distribution between tunnels with a slight difference is observed under isotropic in-situ stress. Numerical modeling enhances stress estimations and reveals changes during tunnel excavation, weakening the rock mass. Ground reaction curve analysis with support measures shows reduced tunnel convergence after implementation, suggesting support strategies like extended bolts using updated rock mass rating. The study improves tunnel design and stability assessment by comprehensively understanding stress redistribution and support strategies.

Due to the increase in population and the increasing need for construction, the issues related to excavation and stability of the excavation have been given importance. The stability of excavations can be controlled and improved by various methods such as anchoring, retaining walls, shielding, etc. that in each project, according to the characteristics of that project and the type of factors threatening the stability of that excavation, one or more stabilization methods can be used. The excavation investigated in this research is stabilized by two pile-anchor and concrete pile methods. One of the factors leading to the instability of the excavation is the infiltration of water into the excavation. Water infiltration into the excavation can be due to various reasons such as rainfall, rise of the underground water level, pipe burst, etc.; Therefore, the possibility of water infiltration into the excavation should be checked in each excavation, and necessary measures should be taken in case of water infiltration. matric suction is defined as the difference between pore air pressure and pore water pressure, which plays a major role in the shear resistance behavior of unsaturated soils; Now, water infiltration reduces matric suction and as a result reduces shear resistance and increases soil volume in expansive soils. The excavation studied in this research has been exposed to factors that change matric suction such as pipe burst, absorption well and climate conditions. The boundary conditions of pipe bursting and absorption well are assumed for a period of one year; Also, the weather conditions have been obtained from the meteorological data of the two rainy months of Sarakhs city. Using sigma/W software and Couple analysis, the simultaneous effect of change in matric suction and change in stress and strain has been investigated. Also, the Penman-Monteith method has been used for the calculation of evaporation and transpiration to model the climate conditions. In this research, a comparison was made between different excavation stabilization situations (pile-anchor and pile method) under different conditions of matric suction (pipe burst, absorption well and weather conditions). Also, in this research, the effect of the location of the burst pipe and absorption well (distance from the excavation wall) on factors such as deformations, the moment created in the pile and the forces created in the anchors (behavior of the excavation) was investigated. Considering the destructive behavior of expansive soils in unsaturated conditions, the soil studied in this research is of expansive type. The characteristics of the modeled soil are related to the area of Sarakhs city. In order to consider the effect of soil swelling, the used elasticity modulus is related to the effective stress and as a result matric suction, which is called the swelling modulus. The results showed that the increase in moisture in the soil and as a result the decrease in matric suction in the swelling soil increases the force in the anchors and the bending moment in the pile. Also, the increase in the force of the anchors and the displacement created in the case of pipe bursting and absorption well modeling is much more than the conditions of the climate boundary effect for the two rainy months of the year. By increasing the distance of the absorption well and the bursting of the pipe from the excavation, the increase in the force created in the anchors decreases. climate conditions affect the upper 6 meters of the excavation, i.e. the active zone.

In the field of underground mining, the steel props within the coal face are frequently not fully salvaged, resulting in a low recovery rate. At the present time, approximately 60% of coal mining is conducted through underground methods. Consequently, there is a growing number of mechanical roof supports that utilize steel props. Furthermore, as the raw materials for the manufacture of these props are becoming increasingly scarce, it is of paramount importance to recover steel supports from unused mine shafts and those situated along coal seams. However, the recovery process is beset with numerous challenges due to the complex geological conditions and the arduous and perilous nature of the work, which has resulted in a dearth of attention to prop recovery in these areas during the coal mining process. Phase 2 software from Rock science was employed to ascertain the impact of the dismantling equipment on the mining excavation. Therefore, this paper presents a technical solution to enhance the efficiency of the steel prop recovery process in these shafts by utilizing a combination of hydraulic and mechanical structures to form a cohesive equipment setup for effective recovery.

Drift-and-fill mining is a variation of cut-and-fill mining method. Drift-and-fill mining method refers to the excavation of several parallel drifts in ore. Excavation of a new drift could start when its adjacent drifts are backfilled or not excavated. The amount of ore material and its grade depends on the excavation sequence of drifts. As the number of drifts increases, one will need a model to optimize the drift excavation and backfilling sequence. This paper introduces a mathematical model to determine the optimal drift-and-fill sequence while the safety constraints, excavation, and backfilling capacities and their dependencies are satisfied. The model seeks to minimize the deviations from some predefined goals, and it handles the long-term and short-term constraints in separate and integrated scenarios. An application of the model is presented based on the data available from a lead/zinc underground mining project. There are 91 drifts in the selected level. Based on the monthly planning horizon, the integrated model leads to the slightest deviations in both the mining rate and average grade, and the deviation from the predetermined annual goals is negligible. For the case where long-term and short-term plans are determined separately, the deviation is approximately 10%.

Facilities built in areas affected by earthquake activity, such as tunnels, which have always been an integral part of human life, must withstand both dynamic and static loading. It has led to the need for practical studies on the effects of earthquakes on underground structures and the factors affecting their destruction. For this purpose, in this research, at first different patterns of tunnel’s excavation were investigated and by using Plaxis 2D software and based on Tabas earthquake in Iran, sensitivity analysis on geotechnical parameters of the soil surrounding tunnel such as cohesion, friction angle, unit weight and modulus of elasticity was carried out, and the parameters whose changes have the greatest and least effects on the bending moment changes on the tunnel lining are introduced. The results show that tunnel excavation patterns significantly affect the bending moment, axial forces, displacements, and surface settlement of the tunnel. Often, by dividing tunnel excavation area to small parts, the values of bending moment, axial forces, displacements, and surface settlement of the tunnel decreases in static analysis. Also, outputs of sensitivity analysis on geotechnical parameters of the soil surrounding tunnel showed that modulus of elasticity of the soil surrounding tunnel has the most effect and cohesion changes have the least effect on bending moment induced on tunnel lining..

The environmental conditions present in underground (UG) mines working site significantly impacts the productivity, efficiency, effectiveness as well as threatened security levels. Consequently, maintaining safety in mineral excavation process requires continuous monitoring of the intricate and perilous operating conditions within the mining work site. At this juncture of time, in this information age, when all walks of life is undergoing continuous modernization, with today's workplace being no exception, Internet of Things (IoT) technology is playing a key role in acquiring relevant information to support monitoring vital operational man and machine safety parameters such as temperature, pressure, humidity, luminance and noise levels, and miner's location in subterranean mining operations. This study has attempted to exhaustively explore state of current research on the use of IoT in underground mining applications. This paper examines the utilization of IoT applications for monitoring several environmental parameters, including obnoxious mine gases and dust concentrations, temperature, humidity, groundwater levels, and strata behaviour to facilitate ground support activities. This paper attempts exploitation of possible scopes of IoT integration from the implementation perspective to monitor and control the various aspects that contribute towards various types and incidents of mine accidents. This research elucidates the primary obstacles that impede the widespread implementation of IoT-enabled systems in underground mining applications.

A better understanding of rock mass behavior is an essential part of the design and construction of underground structures. Any improvement in the understanding of the behavior of rock mass will facilitate the improvement of the design in terms of the safety of the working environment, long-term safety of the structure, environmental effects, and sound management of public or private resources. Thus, in step one in this paper the experience gained from the application of the GDE (Geo Data Engineering) multiple graph approach for rock mass classification and assessment of its behavior through the course of excavation of the Alborz tunnel is presented. The predicted hazards are compared with the experienced problems and suggestions are given to be considered in future works of tunnel construction. In step two, the GDE multiple graph approach is compared to the rock mass behavior types proposed by Palmstrom & Stille (2007) in terms of the continuity of rock mass. The result of this comparison together with the data obtained from rock mass classification in the Alborz tunnel are used to develop a system that determines the applicability of the rock bolt supporting factor (RSF) in different rock mass behavior classes.

The development of underground transportation activities in cities, such as tunnel boring, may exert short-term or long-term effects on the groundwater and springs of such areas. The construction of the tunnel of Tehran Metro Line 6 (TML6) through alluvium and carbonate rocks of Ali Spring has aroused concern due to the caused fluctuations in discharge and temporary dryness of the spring. The hydrochemical properties of the groundwater and catchment area were investigated to find a connection between the aquifers around the spring and determine the major aquifer feeding it. The estimated volume of water penetrated to the tunnel and the most greatly affected area by the water leakage into the tunnel was determined using analytical methods of water leakage into the tunnel and the DHI method. The statistics for precipitation with the changes in the discharge of the spring before and after the excavation of the metro tunnel were compared to evaluate the changes in the discharge of the spring with the precipitation in the area. The results showed that the metro tunnel excavation has dramatically affected the hydrological system of the area and discharge of the Ali Spring. Moreover, continuing the extraction may produce adverse effects on the discharge of other springs and wells and alter the flow system of the area temporarily or forever.

In today’s society, pipelines as vital arteries play a significant role in maintaining people’s peace and satisfaction. According to growing developments in societies, the necessity of constructing, refurbishing, repairing, and maintaining underground installations such as petrol pipelines, gas, water, wastewater, runoffs, and connections is considered as the indispensable part of civil and installation operations. Regarding problems stemming from the open trench excavation methods and growth of underground installations, using trenchless technologies in the construction industry is increasing in order to solve the problems more economically and effectively. The present project aimed at recognizing and ranking the most important effective factors in accepting the trenchless technology in Iran. This research has a practical target and has been performed by the survey and the describing method. The statistical population of this research includes middle managers, contractors, and civil projects engineers of Isfahan province. In this regard, a sample of 87 people was randomly selected and the questionnaire was distributed among them. Eventually, a total of 68 questionnaires were collected with favorable consistency. This questionnaire has been designed by the investigator according to the Likert scale with high stability. Accordingly, the factors were grouped in the form of 28 criteria and 8 major groups as the effective factors on accepting the trenchless technology in Iran. Descriptive and inferential methods and the Friedman test were used to rank the effective factors, and the SPSS software was applied to analyze the data. Among the 8 major groups of executive management, environmental, demographics, technology, economically, project productivity (construction management), organizational, and individual had the first to the 8th rank, respectively. In addition, control system, risks, environment, budget, chief executive officer (CEO), special and geographical performance, and direct costs ranked the top among the 28 factors.