diff --git a/mysql_preview_server.py b/mysql_preview_server.py
index 746435c..a9079f3 100644
--- a/mysql_preview_server.py
+++ b/mysql_preview_server.py
@@ -50,6 +50,7 @@ SITE_SYNC_JOBS = {}
 SITE_SYNC_LOCK = threading.Lock()
 DB_INIT_LOCK = threading.Lock()
 DB_SCHEMA_READY = False
+DB_WRITE_LOCK = threading.Lock()
 
 
 def configure_sqlite_connection(conn):
@@ -64,6 +65,24 @@ def open_db_connection(timeout=30):
     return configure_sqlite_connection(conn)
 
 
+def run_db_write(write_fn, retries=4, delay=0.2):
+    last_error = None
+    for attempt in range(retries):
+        try:
+            with DB_WRITE_LOCK:
+                with open_db_connection() as conn:
+                    ensure_db_schema(conn)
+                    return write_fn(conn)
+        except sqlite3.OperationalError as error:
+            last_error = error
+            if 'locked' not in str(error).lower() or attempt == retries - 1:
+                raise
+            time.sleep(delay * (attempt + 1))
+    if last_error:
+        raise last_error
+    raise RuntimeError('DB write failed')
+
+
 
 def init_db(conn):
     global DB_SCHEMA_READY
@@ -1152,16 +1171,22 @@ def _parse_budget_predeck(rows):
 
 
 def _parse_budget_crossbeam(rows):
-    result = {'height': '', 'length': '', 'quantity': '', 'remarks': ''}
+    result = []
     if len(rows) < 2:
         return result
-    values = rows[1] + [''] * max(0, 4 - len(rows[1]))
-    result.update({
-        'height': _as_text(values[0]).strip(),
-        'length': _as_text(values[1]).strip(),
-        'quantity': _as_text(values[2]).strip(),
-        'remarks': _as_text(values[3]).strip(),
-    })
+    for row in rows[1:]:
+        if not row:
+            continue
+        first = _as_text(row[0]).strip()
+        if not first or '조회된 내용이 없습니다' in first:
+            continue
+        values = row + [''] * max(0, 4 - len(row))
+        result.append({
+            'height': _as_text(values[0]).strip(),
+            'length': _as_text(values[1]).strip(),
+            'quantity': _as_text(values[2]).strip(),
+            'remarks': _as_text(values[3]).strip(),
+        })
     return result
 
 
@@ -4004,25 +4029,13 @@ class Handler(BaseHTTPRequestHandler):
                 q = parse_qs(parsed.query)
                 page_name = q.get('page', ['const'])[0]
                 refresh = q.get('refresh', ['0'])[0] in ('1', 'true', 'yes')
-                with open_db_connection() as conn:
-                    ensure_db_schema(conn)
-                    if refresh:
-                        search_text = q.get('searchText', [''])[0]
-                        result = fetch_erp_project_codes(page_name, search_text)
-                        sync_info = replace_erp_project_code_cache(conn, result['page'], result['rows'])
+                if refresh:
+                    search_text = q.get('searchText', [''])[0]
+                    result = fetch_erp_project_codes(page_name, search_text)
+                    sync_info = run_db_write(lambda conn: replace_erp_project_code_cache(conn, result['page'], result['rows']))
+                    with open_db_connection() as conn:
+                        ensure_db_schema(conn)
                         cached = get_erp_project_code_cache(conn, result['page'])
-                        return self._json(
-                            200,
-                            {
-                                'count': len(cached['rows']),
-                                'rows': cached['rows'],
-                                'source': 'erp_cache',
-                                'page': cached['sourcePage'],
-                                'syncedAt': sync_info['syncedAt'],
-                            },
-                        )
-
-                    cached = get_erp_project_code_cache(conn, page_name)
                     return self._json(
                         200,
                         {
@@ -4030,21 +4043,35 @@ class Handler(BaseHTTPRequestHandler):
                             'rows': cached['rows'],
                             'source': 'erp_cache',
                             'page': cached['sourcePage'],
-                            'syncedAt': cached['syncedAt'],
+                            'syncedAt': sync_info['syncedAt'],
                         },
                     )
 
+                with open_db_connection() as conn:
+                    ensure_db_schema(conn)
+                    cached = get_erp_project_code_cache(conn, page_name)
+                return self._json(
+                    200,
+                    {
+                        'count': len(cached['rows']),
+                        'rows': cached['rows'],
+                        'source': 'erp_cache',
+                        'page': cached['sourcePage'],
+                        'syncedAt': cached['syncedAt'],
+                    },
+                )
+
             if parsed.path == '/api/erp-contract-detail':
                 q = parse_qs(parsed.query)
                 page_name = q.get('page', ['const'])[0]
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 refresh = q.get('refresh', ['0'])[0] in ('1', 'true', 'yes')
+                if refresh:
+                    detail = fetch_erp_contract_detail(page_name, project_code, project_name)
+                    run_db_write(lambda conn: replace_erp_contract_detail_cache(conn, detail))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    if refresh:
-                        detail = fetch_erp_contract_detail(page_name, project_code, project_name)
-                        replace_erp_contract_detail_cache(conn, detail)
                     cached = get_erp_contract_detail_cache(conn, page_name, project_code)
                 if not cached:
                     return self._json(404, {'ok': False, 'error': '계약정보 캐시가 없습니다.'})
@@ -4062,11 +4089,11 @@ class Handler(BaseHTTPRequestHandler):
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 refresh = q.get('refresh', ['0'])[0] in ('1', 'true', 'yes')
+                if refresh:
+                    result = fetch_erp_bridge_overviews(page_name, project_code, project_name)
+                    run_db_write(lambda conn: replace_erp_bridge_overview_cache(conn, result))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    if refresh:
-                        result = fetch_erp_bridge_overviews(page_name, project_code, project_name)
-                        replace_erp_bridge_overview_cache(conn, result)
                     cached = get_erp_bridge_overview_cache(conn, page_name, project_code)
                 return self._json(
                     200,
@@ -4083,11 +4110,11 @@ class Handler(BaseHTTPRequestHandler):
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 refresh = q.get('refresh', ['0'])[0] in ('1', 'true', 'yes')
+                if refresh:
+                    result = fetch_erp_budget_plan(page_name, project_code, project_name)
+                    run_db_write(lambda conn: replace_erp_budget_plan_cache(conn, result))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    if refresh:
-                        result = fetch_erp_budget_plan(page_name, project_code, project_name)
-                        replace_erp_budget_plan_cache(conn, result)
                     cached = get_erp_budget_plan_cache(conn, page_name, project_code)
                 if not cached:
                     return self._json(404, {'ok': False, 'error': '공사시행계획서 캐시가 없습니다.'})
@@ -4271,9 +4298,7 @@ class Handler(BaseHTTPRequestHandler):
                 q = parse_qs(parsed.query)
                 page_name = q.get('page', ['const'])[0]
                 result = fetch_erp_project_codes(page_name)
-                with open_db_connection() as conn:
-                    ensure_db_schema(conn)
-                    sync_info = replace_erp_project_code_cache(conn, result['page'], result['rows'])
+                sync_info = run_db_write(lambda conn: replace_erp_project_code_cache(conn, result['page'], result['rows']))
                 return self._json(
                     200,
                     {
@@ -4294,9 +4319,9 @@ class Handler(BaseHTTPRequestHandler):
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 detail = fetch_erp_contract_detail(page_name, project_code, project_name)
+                sync_info = run_db_write(lambda conn: replace_erp_contract_detail_cache(conn, detail))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    sync_info = replace_erp_contract_detail_cache(conn, detail)
                     cached = get_erp_contract_detail_cache(conn, page_name, project_code)
                 return self._json(
                     200,
@@ -4317,9 +4342,9 @@ class Handler(BaseHTTPRequestHandler):
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 result = fetch_erp_bridge_overviews(page_name, project_code, project_name)
+                sync_info = run_db_write(lambda conn: replace_erp_bridge_overview_cache(conn, result))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    sync_info = replace_erp_bridge_overview_cache(conn, result)
                     cached = get_erp_bridge_overview_cache(conn, page_name, project_code)
                 return self._json(
                     200,
@@ -4341,9 +4366,9 @@ class Handler(BaseHTTPRequestHandler):
                 project_code = q.get('projectCode', [''])[0]
                 project_name = q.get('projectName', [''])[0]
                 result = fetch_erp_budget_plan(page_name, project_code, project_name)
+                sync_info = run_db_write(lambda conn: replace_erp_budget_plan_cache(conn, result))
                 with open_db_connection() as conn:
                     ensure_db_schema(conn)
-                    sync_info = replace_erp_budget_plan_cache(conn, result)
                     cached = get_erp_budget_plan_cache(conn, page_name, project_code)
                 return self._json(200, {'ok': True, 'syncedAt': sync_info['syncedAt'], 'plan': cached})
             except Exception as e:
diff --git a/project-codes.html b/project-codes.html
index 3bb6563..916ef4e 100644
--- a/project-codes.html
+++ b/project-codes.html
@@ -669,13 +669,23 @@
         .replace(/(?<=\d)-(?=\d)/g, '-\n');
     }
 
+    function normalizeCrossbeamRows(crossbeam) {
+      if (Array.isArray(crossbeam)) {
+        return crossbeam.length ? crossbeam : [{ height: '', length: '', quantity: '', remarks: '' }];
+      }
+      if (crossbeam && typeof crossbeam === 'object') {
+        return [crossbeam];
+      }
+      return [{ height: '', length: '', quantity: '', remarks: '' }];
+    }
+
     function renderBudgetPlanInlineTables(plan) {
       if (!plan) return '-';
       const inputDays = plan.inputDays || {};
       const inputRebar = plan.inputRebar || {};
       const girderSpecs = Array.isArray(plan.girderSpecs) ? plan.girderSpecs : [];
       const predeck = plan.predeck || {};
-      const crossbeam = plan.crossbeam || {};
+      const crossbeamRows = normalizeCrossbeamRows(plan.crossbeam);
 
       return `
         <div class="inline-plan-wrap">
@@ -739,27 +749,33 @@
           </table>
           <table class="plan-table plan-table-split">
             <tr>
-              <th rowspan="2">프리덱</th>
+              <th colspan="4">프리덱</th>
+              <th colspan="4">가로보</th>
+            </tr>
+            <tr>
               <th>일반부(㎡)</th>
               <th>중분대(㎡)</th>
               <th>방호벽부(㎡)</th>
               <th>비고</th>
-              <th rowspan="2">가로보</th>
               <th>형고(m)</th>
               <th>길이(m)</th>
               <th>수량(EA)</th>
               <th>비고</th>
             </tr>
-            <tr>
-              <td>${escapeHtml(predeck.generalArea || '-')}</td>
-              <td>${escapeHtml(predeck.medianArea || '-')}</td>
-              <td>${escapeHtml(predeck.barrierArea || '-')}</td>
-              <td class="plan-left">${escapeHtml(predeck.remarks || '-')}</td>
-              <td>${escapeHtml(crossbeam.height || '-')}</td>
-              <td>${escapeHtml(crossbeam.length || '-')}</td>
-              <td>${escapeHtml(crossbeam.quantity || '-')}</td>
-              <td class="plan-left">${escapeHtml(crossbeam.remarks || '-')}</td>
-            </tr>
+            ${crossbeamRows.map((row, index) => `
+              <tr>
+                ${index === 0 ? `
+                  <td rowspan="${crossbeamRows.length}">${escapeHtml(predeck.generalArea || '-')}</td>
+                  <td rowspan="${crossbeamRows.length}">${escapeHtml(predeck.medianArea || '-')}</td>
+                  <td rowspan="${crossbeamRows.length}">${escapeHtml(predeck.barrierArea || '-')}</td>
+                  <td rowspan="${crossbeamRows.length}" class="plan-left">${escapeHtml(predeck.remarks || '-')}</td>
+                ` : ''}
+                <td>${escapeHtml(row.height || '-')}</td>
+                <td>${escapeHtml(row.length || '-')}</td>
+                <td>${escapeHtml(row.quantity || '-')}</td>
+                <td class="plan-left">${escapeHtml(row.remarks || '-')}</td>
+              </tr>
+            `).join('')}
           </table>
         </div>
       `;
@@ -920,7 +936,7 @@
       const inputRebar = plan.inputRebar || {};
       const girderSpecs = Array.isArray(plan.girderSpecs) ? plan.girderSpecs : [];
       const predeck = plan.predeck || {};
-      const crossbeam = plan.crossbeam || {};
+      const crossbeamRows = normalizeCrossbeamRows(plan.crossbeam);
 
       planModalTitle.textContent = `${bridgeName || plan.projectName || '프로젝트'} 공사시행계획서`;
       planModalBody.innerHTML = `
@@ -948,10 +964,25 @@
         </table>
         <div class="plan-section-title">교량제원 - 프리덱 / 가로보</div>
         <table class="plan-table">
-          <tr><th>프리덱 일반부</th><td>${escapeHtml(predeck.generalArea || '-')}</td><th>가로보 형고</th><td>${escapeHtml(crossbeam.height || '-')}</td></tr>
-          <tr><th>프리덱 중분대</th><td>${escapeHtml(predeck.medianArea || '-')}</td><th>가로보 길이</th><td>${escapeHtml(crossbeam.length || '-')}</td></tr>
-          <tr><th>프리덱 방호벽부</th><td>${escapeHtml(predeck.barrierArea || '-')}</td><th>가로보 수량</th><td>${escapeHtml(crossbeam.quantity || '-')}</td></tr>
-          <tr><th>프리덱 비고</th><td>${escapeHtml(predeck.remarks || '-')}</td><th>가로보 비고</th><td>${escapeHtml(crossbeam.remarks || '-')}</td></tr>
+          <tr><th colspan="2">프리덱</th><th>형고(m)</th><th>길이(m)</th><th>수량(EA)</th><th>비고</th></tr>
+          ${crossbeamRows.map((row, index) => `
+            <tr>
+              ${index === 0 ? `<th>일반부(㎡)</th><td>${escapeHtml(predeck.generalArea || '-')}</td>` : ''}
+              ${index === 1 ? `<th>중분대(㎡)</th><td>${escapeHtml(predeck.medianArea || '-')}</td>` : ''}
+              ${index === 2 ? `<th>방호벽부(㎡)</th><td>${escapeHtml(predeck.barrierArea || '-')}</td>` : ''}
+              ${index >= 3 ? `<th>비고</th><td>${escapeHtml(predeck.remarks || '-')}</td>` : ''}
+              <td>${escapeHtml(row.height || '-')}</td>
+              <td>${escapeHtml(row.length || '-')}</td>
+              <td>${escapeHtml(row.quantity || '-')}</td>
+              <td>${escapeHtml(row.remarks || '-')}</td>
+            </tr>
+          `).join('')}
+          ${crossbeamRows.length < 4 ? `
+            ${crossbeamRows.length <= 0 ? '' : ''}
+            ${crossbeamRows.length < 2 ? `<tr><th>중분대(㎡)</th><td>${escapeHtml(predeck.medianArea || '-')}</td><td colspan="4"></td></tr>` : ''}
+            ${crossbeamRows.length < 3 ? `<tr><th>방호벽부(㎡)</th><td>${escapeHtml(predeck.barrierArea || '-')}</td><td colspan="4"></td></tr>` : ''}
+            ${crossbeamRows.length < 4 ? `<tr><th>비고</th><td>${escapeHtml(predeck.remarks || '-')}</td><td colspan="4"></td></tr>` : ''}
+          ` : ''}
         </table>
       `;
     }