Guidelines for Installation of Sensors in Smart Sensing Platforms in Underground Spaces

The purpose of this study is to propose guidelines for sensor installation in different types of underground space smart sensing platforms. Firstly, we classify the underground space, analyze the scene requirements according to the classification of underground space, and sort out the requirements for sensors in various types of underground space. Secondly, according to the requirements of underground space scenes for sensors, the types of sensors and corresponding parameters are clarified. After that, the system design and sensor installation guidelines of the underground space smart sensing platform are proposed by sorting out the data acquired by the sensor.


Introduction
This paper clarifies the sensor types and corresponding parameters for smart sensing scenes by analyzing the needs of different types of underground space scenes. Based on the sensor parameters and acquired data required by the underground space smart sensing platform system, the sensor installation guidelines are formed accordingly.
This study needs to clarify types of underground spaces, and we can refer to the laws and regulations of underground spaces in each country. Japan has a perfect legal and management mechanism for underground spaces [1][2][3][4], such as the "Act on Special Measures concerning Public Use of Deep Underground", which clarifies the specific problems and technical measures for underground space utilization. Meanwhile, for different types of underground spaces, there are different technical standards and construction regulations [5], such as "Standard Specification for Tunneling" and so on. The "State Lands Act" and "Land Acquisition Act" clarify the classification basis and ownership of underground spaces, and the "Common Services Tunnels Act" and others have introduced new technical requirements for different underground spaces. There are also different technical standards and construction procedures in different underground space classifications such as "Railway applications Fixed installations Electric traction overhead contact lines". In the United States, there is also a relatively complete legal and management mechanism for underground space [6], and state laws such as "Laws of Minnesota for 1985 Mined Underground Space" and "Oklahoma Statutes Property" have clarified the technical measures in the development and use of underground space according to the characteristics of each state. There are also different technical standards and construction procedures in Table 1. Summary of the requirements of the existing guidelines for underground space devices and the devices commonly used in the current underground space.

Rules for Equipment Requirements Mentioned in the Guidelines Current Use of the Devices
Lighting Equipment

Theoretical Concept and Methodology
To meet the monitoring and early warning needs of maintenance management, this study considers that the guidelines for setting up sensors in underground spaces need to clarify the classification of underground spaces and also the properties of sensors such as communication methods, the properties of data and the basic framework of the sensing system, thus taking the following research steps to propose guidelines for setting up sensors for smart scenes in underground spaces: 1.
Classify the underground space according to the classification standard of Japanese underground space and the functional characteristics of each type of underground space, and by clarifying the functional requirements of each type of underground space for sensors on the basis of the classification of underground space; 2.
Based on the above-mentioned requirements for sensors in the underground space, the sensors are screened on the basis of the temperature and humidity applicable to the underground space, and the sensor types and parameters are selected to meet the smart scene and functional requirements of the underground space; 3.
Based on the functional requirements met by the above sensors as well as the sensor types and parameters, the types of data acquired by each type of sensor and the data attributes are clarified; 4.
Based on the classification of underground space, sensor attributes and data attributes in I, II and III above, clarify the data transmission methods and data flow between sensors of various types of data, propose the basic framework of smart sensing system in underground space and form the guidelines for setting up sensors for smart scenes in underground space.

Underground Space Classification and Scene Requirements Analysis
Various types of underground spaces have different needs for sensors. Since the planning and construction of underground spaces in Japan is at an advanced level internationally, this study refers to the Japanese classification standard for underground space, which distinguishes between civilian land and public land, and classifies underground spaces according to the depth of various underground facilities in Figure 1. space, and by clarifying the functional requirements of each type of underground space for sensors on the basis of the classification of underground space; 2. Based on the above-mentioned requirements for sensors in the underground space, the sensors are screened on the basis of the temperature and humidity applicable to the underground space, and the sensor types and parameters are selected to meet the smart scene and functional requirements of the underground space; 3. Based on the functional requirements met by the above sensors as well as the sensor types and parameters, the types of data acquired by each type of sensor and the data attributes are clarified; 4. Based on the classification of underground space, sensor attributes and data attributes in I, II and III above, clarify the data transmission methods and data flow between sensors of various types of data, propose the basic framework of smart sensing system in underground space and form the guidelines for setting up sensors for smart scenes in underground space.

Underground Space Classification and Scene Requirements Analysis
Various types of underground spaces have different needs for sensors. Since the planning and construction of underground spaces in Japan is at an advanced level internationally, this study refers to the Japanese classification standard for underground space, which distinguishes between civilian land and public land, and classifies underground spaces according to the depth of various underground facilities in Figure 1. Based on the Japanese classification standard for underground space, underground space can be divided into six types of underground infrastructure: rail transit, under-  Based on the Japanese classification standard for underground space, underground space can be divided into six types of underground infrastructure: rail transit, underground functional places (underground stores, parking lots, subway stations, etc.), elevated bridges, underground tunnels, underground municipal pipelines, and underground heat source heat pumps in Table 2. Different functions of the underground space are monitored differently during maintenance. Therefore, there are also differences in the requirements for sensors. In order to meet the operational requirements ( Figure 2), the discussion needs to be based on the classification of the underground space in question. ground functional places (underground stores, parking lots, subway stations, etc.), elevated bridges, underground tunnels, underground municipal pipelines, and underground heat source heat pumps in Table 2. Different functions of the underground space are monitored differently during maintenance. Therefore, there are also differences in the requirements for sensors. In order to meet the operational requirements ( Figure 2), the discussion needs to be based on the classification of the underground space in question. Underground spaces have different requirements for various types of sensors in different types of spaces, which are organized according to the Table 3 below. Obtain support structure information Reduce the collapse potential caused by damage such as support cracks, and deal with cracks that have a greater impact in a timely manner Underground municipal pipeline Real-time monitoring of pipeline structure Prevent the occurrence of liquid leakage and air leakage, and respond to liquid leakage and air leakage in a timely manner Underground spaces have different requirements for various types of sensors in different types of spaces, which are organized according to the Table 3 below. Table 3. Summary of underground space requirements.

Smart Scene Type Requirements Purpose
Basic scenes (generic scenes)

Monitoring of natural and man-made disasters
Response before and after disasters, mainly natural disasters (flooding, earthquakes, extreme weather (extreme cold and heat, thunderstorms)) and man-made disasters (fire, equipment failure, construction personnel health)

Monitor construction and operational environments
Monitoring and adjusting the air environment, sound environment, geotechnical environment, and light environment to make people feel comfortable Obtain information on pillar structure Prevention of collapse due to damage to the column structure Table 3. Cont.

Smart Scene Type Requirements Purpose
Underground tunnel Obtain support structure information Reduce the collapse potential caused by damage such as support cracks, and deal with cracks that have a greater impact in a timely manner

Underground Space Sensor Sorting
Based on the classification of the underground space, and the requirements of sensors for different underground space scenarios, the sensors on the market are screened on the basis of the temperature and humidity applicable to underground space, and the types of sensors and the corresponding parameters of sensors that can meet the needs of the scenario are obtained in Table 4.

Underground Space Data Sorting
Based on the functional requirements of the underground space for sensors, sensor types and parameters, the attributes of the data acquired by various types of sensors are clarified, including data transmission methods and data monitoring scopes. The final results will be classified based on data types and attributes to form a data summary table (Table 5).

Basic Framework of Underground Space Smart Sensing Platform
Based on the analysis of underground space classification and scene requirements, sensor attributes and data attributes, the framework of underground space smart sensing platform (smart sensing system control) is proposed in Figure 3. Based on the data transmission methods and data flow between sensors in the underground space, the data flow of the sensing platform is clarified in Figure 4: smart monitoring devices (sensors) acquire data Multiple sensors are combined to form smart scenarios The data acquired by each sensor is integrated as task (or the data acquired by each scene as Ambience), through the central processor and the database data for comparison, through the network transport module to the database module (update data without problems) or data report generation visualization real-time management module (problem data for feedback) feedback to smart monitoring equipment (alarm device) through forecast and early warning module with problematic data. Based on the data transmission methods and data flow between sensors in the underground space, the data flow of the sensing platform is clarified in Figure 4: smart monitoring devices (sensors) acquire data Multiple sensors are combined to form smart scenarios The data acquired by each sensor is integrated as task (or the data acquired by each scene as Ambience), through the central processor and the database data for comparison, through the network transport module to the database module (update data without problems) or data report generation visualization real-time management module (problem data for feedback) feedback to smart monitoring equipment (alarm device) through forecast and early warning module with problematic data.

Production of Sensor Installation Guidelines for Underground Space
In this paper, we make a summary analysis of the requirements of different underground space types to clarify the types of underground space sensor requirements as well as the parameters of the sensors and the monitoring data of the underground space to form the sensor installation guidelines in the underground space smart sensing platform. To facilitate the designers to carry out the design work related to the underground space smart, we will finally form the sensor design and installation guidelines table (Table 6) and the installation location schematic according to the characteristics of the sensors used in different scenarios (Figures 5-16).   Shield construction method: continuous excavation and discharge of sand and soil is required; Earth cutting: to prevent subsidence, groundwater protrusion and inflow of soil and sand into the end well, reinforcement and improvement of the soil around the cavern ring are required; Soil cutting volume: the cutting soil and sand must be discharged exactly in line with the amount of excavation; 4. Equipment: the shield machine has the feature that it can only enter but not retreat, so pay attention to the construction status of the shield machine.  3 implementing water pressure test. 4 laying of buried marker plate. 5 setting buried markers on the ground surface. 6 Confirming the construction around the header.
2. Heat exchange well section. 1 Capture geological information Record in excavation. 2 Simultaneous setting confirmation of water tension in the underground heat ex-changer, proper reloading, and thermometer setting at insertion. underground heat exchanger, proper reloading, and thermometer setting at insertion.
Self-painted by the author.   The door opens automatically after entering the detection range of new-type PSD, after which drop test camera opens and the user enters the detection range of drop test camera. (d): When the user falls off the track, environment resistance obturation sensor will sound an alarm. He or she will remain in the detection range of drop test camera. At this time, drop test camera will determine the location of the fall accident and upload it.

Conclusions
In this paper, we analyze the requirements of different types of underground space scenes and clearly establish the sensor types and corresponding parameters for smart sensing scenes. Based on the sensor parameters and the acquired data, we propose a system design for smart sensing platform in underground space and form the sensor installation guidelines accordingly. The guidelines are mainly divided into two parts: installation guideline table and installation schematic, and the purpose of setting the guidelines is to guide the work related to the construction of smart scenes in underground space.
The study of requirements in this paper focuses largely on maintenance management. The next step will be to refine the process of developing and constructing smart scenes in underground spaces, and to propose different development proposals and guidelines at different phases according to the refined process.

Conclusions
In this paper, we analyze the requirements of different types of underground space scenes and clearly establish the sensor types and corresponding parameters for smart sensing scenes. Based on the sensor parameters and the acquired data, we propose a system design for smart sensing platform in underground space and form the sensor installation guidelines accordingly. The guidelines are mainly divided into two parts: installation guideline table and installation schematic, and the purpose of setting the guidelines is to guide the work related to the construction of smart scenes in underground space.
The study of requirements in this paper focuses largely on maintenance management. The next step will be to refine the process of developing and constructing smart scenes in underground spaces, and to propose different development proposals and guidelines at different phases according to the refined process.
Author Contributions: Conceptualization, X.T. and Z.S.; methodology, X.T.; software, Z.S.; validation, Z.S. and X.T.; formal analysis, X.T.; investigation, Y.Z. and W.X.; resources, X.T.; data curation, Y.Z.; writing-original draft preparation, Y.Z. and X.T.; writing-review and editing, X.T. and Y.Z.; Figure 16. Smart interaction function for underground heat source heat pump. (a): Smart devices in drainage pipes. Water monitoring devices and pipeline structure monitoring devices are the main focus. All kinds of devices are linked by optical fiber, and the electrical signal is transmitted to the data recorder and wireless transceiver after water quality problems or structural problems, and uploaded by the wireless transceiver. (b): Smart devices in comparison wells, intake wells and drainage wells. Water quality monitoring devices and well structure monitoring devices are the main focus.

Conclusions
In this paper, we analyze the requirements of different types of underground space scenes and clearly establish the sensor types and corresponding parameters for smart sensing scenes. Based on the sensor parameters and the acquired data, we propose a system design for smart sensing platform in underground space and form the sensor installation guidelines accordingly. The guidelines are mainly divided into two parts: installation guideline table and installation schematic, and the purpose of setting the guidelines is to guide the work related to the construction of smart scenes in underground space.
The study of requirements in this paper focuses largely on maintenance management. The next step will be to refine the process of developing and constructing smart scenes in underground spaces, and to propose different development proposals and guidelines at different phases according to the refined process.