Assessment and mapping of quality of surface water are essential because chemical and physical characteristics of the water determine its suitability for domestic, industrial, and agricultural usages. Geographic information system (GIS) is an effective and efficient technique in problem-solving where spatial data are essential. Six Physicochemical parameters; Biological Oxygen Demand, Minimum Dissolved Oxygen, Level of Acidity or pH, Nitrate, Phosphate, and Ammonia from Laguna Lake and its tributary rivers were examined from the year 2016 to 2019. Ordinary Kriging and Universal Kriging were used as the spatial interpolation methods that carried out the estimation of the concentrations of the parameters at the unsampled location. It showed that Ordinary kriging performed better compared to Universal Kriging. This paper attempted to obtain the water quality index (WQI) from the year 2016 to 2019. Results showed that Laguna Lake has a WQI rank of marginal to excellent. The WQI of its tributary rivers is mostly poor. The physicochemical parameters indicated that the life of the lake and its tributaries are in threat. Rehabilitation must be given attention and must be suitably planned and executed. The national government and the responsible authorities must collaborate for the effort in rehabilitating and cleaning.

Structural Health Monitoring (SHM) is not new in the field of structural engineering and its application goes from the monitoring to evaluation of bridges, dams, buildings, and other similar structures. As per National Structural Code of the Philippines (NSCP) Volume 1[1-4], the Implementing Rules of earthquake recording instrumentation of buildings has been continually advancing, but not in the case of bridges and dams. The objective of this paper is to apply the established sensor-driven accelerometer developed by USHER (Universal Structural Health Evaluation and Recording) system in the evaluation of Padre Jacinto Zamora Bridge in Manila; specifically, to determine the proper installation of the developed accelerometer in the identified critical parts of the bridge. SHM addresses the problem of structural integrity assessment and help in assuring repair cost to a minimal. SHM helps quantify the strength of a structure by identifying the damage. Often evaluations are made using visual inspection and by age consideration. Most of the time, the use of this type of evaluation tend to be expensive. Repairs are not directed to the damaged component alone but the whole structure. Hence, the expenditure expands. SHM with the application of Micro-Electro-Mechanical Sensors (MEMS) will allow gathering of data that can be converted in the form of the structure’s modal properties (i.e. natural frequency, mode shape, and damping ratio) [6, 7]. Structural health is then determined and be ready to compare it to the structural model simulation results. A method was developed to incorporate seismic fragility curves [5] to determine the thresholds for the evaluation of the structural health. Capacity spectrum method was utilized to derive the seismic fragility function. A Monte Carlo Simulation was used to derive the flood fragility curves.

Bridge load limit monitoring is a major problem in the Philippines. Since this was not implemented strictly, the structural integrity of the bridges was affected hence it resulted to frequent maintenance, retrofitting of strucutral members and collapse. The integrity of the bridge continously decreases through time once the maximum load limit was experienced by the structure. Therefore, this study aims to emphasize the importance of traffic load monitoring in conducting structural health assessment of bridges aside from earthquake and mass loads. The 7.7% increase in the flexure stress of the bridge deck indicates that truck loading has a significant effect on the bridge. In addition for this, variation on the truck volume for peak hours and non peak hours will correlate to the reading of the smart sensor attached on the bridge for structural health monitoring.

No abstract

Philippines is located in the pacific ring of fire, which indicates that seismic movement is frequently happening. West valley fault line located in the central Luzon might move due to its 400 to 500-year recurrence, and the last recorded movement was on 1958. According to MMIERS, the movement of west valley fault with 7.2 magnitude earthquake can cause one of the biggest devastation in Metro Manila. In preparation for that, this study aims to assess the vulnerability of a pre-stress bridge against seismic movement by the aid of USHER technology. The USHER system includes structural assessment, remote sensing, and real time monitoring through the portal. This study will focus on the structural assessment of the bridge, which identify the acceleration limits that the bridge can endure to interpret different level of damage. As a result, by 10% of probability of exceedance from SEAOC using the moderate damage fragility curve, the results in three directions are 0.37641g in longitudinal axis, 0.366025g in transverse axis, and 0.394498g in the vertical direction. The most critical is in the transverse direction, which can produce a maximum of 67mm displacement of the bridge in the inelastic stage. In validation through the sensor, which has a reading from the smart bridge project, the maximum acceleration recorded was 0.138g. This concludes that the bridge is safe and no retrofitting works is need.