左洞起訖樁號LK405+932~LK408+495,長2563m,右洞起訖樁號RK406+096~RK 408+543,長2447m,兩洞總長度為4983m。單洞凈寬14.992m,凈高7.90m的三心圓弧拱型式,兩側(cè)各設(shè)0.75m的檢修道。兩洞間共設(shè)置三條行人橫洞、兩條行車橫洞,行人橫洞分別長87.755m、88.303m,59.827m,斷面為凈寬2.5m,凈高3.3m的直墻圓弧拱形式;行車橫洞分別長115.759m,87.810m,斷面為凈寬5.0m,凈高6.4m的直墻圓弧拱形式。
主要監(jiān)測左洞:LK407+930、LK408+225 右洞:RK408+231、RK408+098兩個(gè)斷面。每個(gè)斷面主要監(jiān)測(1)襯砌裂縫;(2)拱頂?shù)某两?;?/span>3)襯砌溫濕度和環(huán)境溫濕度;(4)周邊的收斂;(5)不均勻沉降監(jiān)測;(6)應(yīng)力應(yīng)變監(jiān)測。
1. 拱頂?shù)某两担好繂蝹€(gè)監(jiān)測斷面布置2個(gè)測點(diǎn);
2. 裂縫的監(jiān)測:每單個(gè)監(jiān)測斷面選取有代表性的裂縫監(jiān)測1條;
3. 溫濕度監(jiān)測: 每個(gè)斷面1個(gè)監(jiān)測點(diǎn),監(jiān)測襯砌溫濕度和環(huán)境濕溫度;
4. 監(jiān)測數(shù)據(jù)存儲與展示:監(jiān)測設(shè)備主控智能網(wǎng)關(guān)內(nèi)置64Gflash存儲芯片,本地?cái)?shù)據(jù)可以長期留存;
5. 應(yīng)力應(yīng)變監(jiān)測:監(jiān)測各斷面應(yīng)力應(yīng)變的變化,每個(gè)斷面5個(gè)監(jiān)測點(diǎn);
6. 不均勻沉降監(jiān)測:采用液壓式靜力水準(zhǔn)儀每個(gè)斷面監(jiān)測一個(gè)點(diǎn)。