橋上的(de)大(dà)門
松山國家級自然保護區(qū)的(de)入口設在兩山之間面南(nán)的(de)一條小溪之上，一座東西走向的(de)公路橋北(běi)側。
基地夾在東西兩側的(de)山峰之間，山上流下(xià)的(de)溪水(shuǐ)在基地北(běi)側彙聚成了(le)一個(gè)水(shuǐ)潭。這(zhè)一潭水(shuǐ)甯靜中包容著(zhe)四季的(de)變化(huà)，山，水(shuǐ)，橋，瀑及植被這(zhè)些自然的(de)元素，共同構成了(le)松山入口處的(de)自然環境特征。
我們把松山大(dà)門作爲一個(gè)集散和(hé)疏導人(rén)流的(de)重要場(chǎng)所來(lái)設計。大(dà)門東西兩端分(fēn)别設置了(le)售票(piào)辦公空間和(hé)紀念品服務商店(diàn)。中置的(de)弧型牆将大(dà)門分(fēn)割成了(le)内外兩個(gè)區(qū)域，這(zhè)些區(qū)域都分(fēn)别設置了(le)休息座椅。遊客在大(dà)門的(de)區(qū)域内可(kě)以随性停留。
動線，大(dà)門結合北(běi)側的(de)水(shuǐ)塘形成一個(gè)小環線，進出人(rén)流不交叉。
視線，遊客從外部看到是兩山之間一道比橋面略高(gāo)的(de)屋頂脊線。從景區(qū)内看，廊橋隐藏于環境之中。弧形牆的(de)中間開設的(de)景窗(chuāng)，讓景區(qū)内的(de)流水(shuǐ)和(hé)潭邊的(de)景物(wù)撲面而來(lái)。
曲線，大(dà)門的(de)兩側是高(gāo)起的(de)山峰。大(dà)門起到續接自然的(de)圖景，以屋頂的(de)一條下(xià)弦弧線完成兩邊山勢的(de)連接，同時(shí)又與下(xià)面的(de)橋洞形成了(le)倒影(yǐng)般的(de)映射關系。
Gates on the bridge
-- Entrance of Beijing Songshan National Nature Reserve
The entrance of the Songshan National Nature Reserve is located on a small stream facing south between the two mountains, and on the north side of an east-west highway bridge.
The base is sandwiched between the peaks on the east and west sides, and the streams flowing down the mountain converge into a water pond on the north side of the base. The pond contains the changes of the four seasons. The natural elements of mountains, water, bridges, waterfalls and vegetation together form the natural environmental characteristics.
The gate is an important place for visitor’s gathering and leaving. Ticket office and souvenir shop are set at the east and west ends while the central curved wall divides the gate into two areas, the inside and the outside, each of which have many seats. Visitors can have a rest at these areas.
Circulation, a small loop combines with the north pond.
Sight, from outside there is a roof ridge line slightly higher than the bridge deck. inside, the covered bridge is hidden in the environment. The hole in the middle of the curved wall lets the flowing water and the scenery come out.
Curve, the gate serves as a continuation of the natural landscape. A lower chord arc on the roof completes the connection between the two sides of the mountain, and at the same time forms a reflective view with the bridge.
