Analysis of the Structure of the Existing Mess Korem 012 Building as an Alternative Safety Building in Meulaboh

. West Aceh district is one of the districts that was affected by the earthquake and tsunami that occurred in 2004. As a district that is in a strong earthquake condition, the aspect of earthquake-resistant buildings is an important object of concern. The Mess Ex KOREM 012 building is one of the buildings that was affected by the 2004 earthquake and tsunami tragedy, resulting in damage to structural elements. There are still very few alternative rescue buildings in Meulaboh, so the former Korem 012 Mess Building is an alternative that can be used to build this building. So this study aims to determine the structural capacity of the Mess Existing Korem 012 building which is intended as an alternative rescue building. This research method uses response spectrum analysis using the Structural Analysis Program (SAP2000) to obtain a structural response to the internal forces of the structure. These data were then processed again with SNI 2847-2019 in order to obtain data on the interaction of forces and moments of the P-MM column ratio and the joint ratio of beam-column relations (HBK). To produce data on the ability of structural elements in accordance with the Requirements for Special Moment-Bearing Frame Systems (SRPMK). The results of the analysis show that in the column area, there is a P-MM condition and the joint ratio HBK > 1. This shows that the ratio of structural capabilities exceeds the capability of the structure, thus the structure of the Mess Ex Korem 012 Building must be repaired to meet the earthquake-resistant building requirements of the SRPMK so it deserves to be used as an alternative rescue building in Meulaboh.


Introduction
The city of Meulaboh, Aceh Province, Indonesia, was badly damaged by the 26 December tsunami.The rush of water reaches 4 km inland.Settlements and facilities along the coastal area were destroyed [1].Responding to this disaster, the central and regional governments have decided to prepare cities to be able to face the tsunami disaster by implementing regional rehabilitation and reconstruction programs that embed disaster mitigation aspects.The aspect of infrastructure damage that was affected by the tsunami disaster in 2004 was damage to residential buildings, offices and economic activity centers (markets).As a result of the damage to the infrastructure, the Government of Aceh carried out a large-scale reconstruction.However, considering the quantity of damage to the infrastructure, the government should pay attention to the structural strength of the buildings to be constructed to prevent the same damage if a similar disaster occurs again.If the structure of a building is not able to withstand the load from the linear elements, the building will experience construction failure.One of the evaluation results that is often obtained for building infrastructure or high-rise buildings is damage after an earthquake, which can be visually observed for cracks in several parts of the building [2].
The problems of buildings caused by earthquakes are usually more directed to the structural part of a building.The impact of earthquakes on buildings is often only discussed about technical issues related to building strength calculations.This is very understandable, but not entirely true, because the safety of users of a building does not only depend on the strength of the structure but also on overall design concept of the building (Idham, 2014).During an earthquake, the energy that destroys a lot of buildings is seismic energy.According to Ghaidan in Idham (2014), the distribution of seismic energy affects wave characteristics such as duration, amplitude, and frequency [1].
The city of Meulaboh, West Aceh is one of the areas affected by the 2004 Aceh earthquake and tsunami, so parts of the building structure in locations affected by the earthquake and tsunami experienced a decrease in concrete strength compared to areas that were not affected, but several buildings affected by the tsunami are still standing.Upright Samsunan (2015), thus re-checking the strength of this structure is very necessary to determine the capacity and feasibility of the building to be occupied, so that it is safe and comfortable to be occupied with the function of each building [2].
In this study, observations were made of buildings, namely the former West Aceh Korem Dormitory Building.

Methodology
Earthquakes are a natural phenomenon that is very dangerous for the buildings above it, where earthquakes cause a lot of loss and damage, especially to building structures that are crossed by the earthquake [5].The current state of Indonesia's seismicity BMKG records that from 1976-2006 there have been 3,486 with a magnitude of more than 6.0 SR, and since 1991-2009 there have been 13 major damages and tsunamis caused by earthquake phenomenan [3].This is also inseparable from the condition of Indonesia which is located at the meeting point of the earth's plates, as can be seen in Figure 1 as follows.The planning data used in the case study includes the Mess Esk Korem 012 West Aceh with an earthquake priority factor of 1.In evaluating the seismicity of buildings, a plan spectrum response analysis is used based on SNI 1726-2019 where the site classification at the location is SE.To make it easier to retrieve spectrum response data, the authors use data issued directly from PUPR.co.id as a reference for the response spectrum loads of the three buildings.Figure 5 shows the design response spectrum graph in the SE site class (Soft Soil).The design response spectrum and parameters can be seen in Table 1 design response spectrum data.The yield mechanism is the concept of inelastic yield in buildings where it is hoped that this yield mechanism will occur first in the beam so that the concept of an earthquakeresistant building with a strong column weak beam can be fulfilled (Dewobroto, 2016).This behavior must be fulfilled to avoid the instantaneous collapse of buildings.where the collapse behavior can be seen in Figure 6 and the limitation of the SCWB value can be seen in equation 1 as follows.
∑Mn > ∑M b (1) Where, ∑Mn = total moment on a column ∑Mb = total moment on beams The minimum bending strength of this column aims to avoid yielding in the column which is considered to be designed as a seismic design bearer (SNI 2847, 2019).Evaluation of earthquake resistance for existing buildings, the vulnerability of existing buildings can be carried out before an earthquake occurs based on the Federal Emergency Management Agency (FEMA 154).A simple evaluation can be carried out based on FEMA 154 called Rapid Visual Screening (RVS), which is a visual examination of the condition of the building including structural, non-structural, architectural and utility buildings, after inspection the building can then be categorized as at risk or not for an earthquake [5].Further inspection can be carried out with a more in-depth structural analysis with existing data as a reference for analyzing the building structurally, even though the structural elements that are evaluated include all elements.For inspection of the existing column, an examination of the strength ratio obtained from the P-M-M ratio issued by the SAP2000 program shows the relationship between axial force (P) and moment (M).

Result and Discussion
The description of the building including area and height can be seen in Table 2 below.The analysis was carried out using the location spectrum response loading, the following can be seen in Figure 7 the response of the structure to loading.From the results of the analysis that has been carried out, the basic shear forces due to the loading spectrum response to the building are obtained, this includes the basic shear forces for the x and y directions in the building and can be seen in table 3 as follows.

OK OK
The results of the analysis also include connectivity between columns and column beams which are a requirement for strong column weak beam SCWB in buildings with a moment resisting frame system (SRPMK), as well as checking the P-MM ratio for columns to determine the capacity of the columns in each building.The P-MM ratio can be seen in table 4 and for the joint ratio it can be seen in table 4 as follows.From the results of the evaluation of the P-M-M ratio and joint ratio, it can be seen that the P-M-M in the column at the Mess Ex Korem location > 1, which from this shows that there is an overstrength column, this indicates that the HBK is not fulfilled in several columns.For the results of the P-MM ratio in the Mess Eks Korem building after several structural elements were given a solution by adding the cross-sectional area and the number of reinforcement resulting in P-MM < 1 can be seen in table 6 as follows.

Conslusion
From evaluating the strength of the structure with the help of SAP2000 software in the Mess Ex Korem 012 building, the conclusions obtained are as follows: 1.The factors affecting the P-MM ratio > 1 are due to the column cross-section and the percentage of the amount of reinforcement that is lacking in the column of the Existing Korem Mess Building.2. Factors affecting the joint ratio > 1 due to the amount of column reinforcement in the Mess Ex Korem 012 Building 3. The value of the P-MM ratio and joint ratio < 1 after being given a conservative solution in accordance with SNI 2847 the addition of cross-sectional area and reinforcement in the column.

Fig 2 .
Fig 2. Front View of the Korem 012 West Aceh Mess Building

Fig 3 .
Fig 3. Condition of column of the Korem 012 West Aceh Mess Building

Fig 4 .
Fig 4. Condition of beams and floor plates of the Korem 012 West Aceh Mess Building

Fig 5 .
Fig 5. Design response spectrum of the Korem 012 West Aceh Mess Building

Fig 7 .
Fig 7. (a) idealized translation in the x direction, (b) idealized translation in the y direction, (c) idealized rotation in the z direction.It can be seen in Figure (a) the condition of the structure undergoes translation in the x direction, Figure (b) the condition of the structure undergoes translation in the y direction, Figure (c) the condition of the structure undergoes rotation in the direction of the z axis.This condition is in accordance with the response criteria for the translation structure x,y then rotation.From the results of the analysis that has been carried out, the basic shear forces due to the loading spectrum response to the building are obtained, this includes the basic shear forces for the x and y directions in the building and can be seen in table 3 as follows.

Table 1 .
Design Response Spectrum Data

Table 1 .
Structural data

Table 3 .
Seismic base shear force

Table 5 .
Rasio Joint Column and Beam

Table 6 .
P-MM column ratio of the Mess Ex Korem 012 building after being enlarged Column area of Mess Ex Korem Building with P-MM force and moment interaction and joint ratio < 1